CN116174168A - Flotation cell - Google Patents

Abstract

A flotation cell for treating particles suspended in a slurry is disclosed. The flotation cell includes: a flotation cell (10), the flotation cell (10) comprising a center (11), a periphery (12), a substantially horizontal flat bottom (13), and a side wall (14); -a launder (2) surrounding the perimeter (12) of the trough (10), -a launder rim (21); an open froth surface (Af) at the top of the flotation cell (10); and a foam plug (6) shaped to direct foam (5) in the open foam area (Af) towards the launder edge (21); and a jet pipe (4) for introducing a slurry feed (100) into the flotation cell. In addition, a flotation line and the use of the flotation line are disclosed.

Description

Flotation cell

This application is a divisional application of an invention patent application named "Flotation Cell" and application number 201910706195.4.

technical field

The present disclosure relates to a flotation cell for separating particles containing valuable material from particles suspended in a slurry, and a flotation line and use thereof.

Contents of the invention

The flotation cell according to the present disclosure is characterized by the flotation cell set forth in claim 1 .

The flotation line according to the present disclosure is characterized by the flotation line set forth in claim 25 .

The use of the flotation line according to the present disclosure is characterized by what is stated in claim 30 .

A flotation cell is provided for treating particles suspended in a slurry and separating the slurry into an underflow and an overflow. The flotation cell comprises: a flotation cell comprising a center, a perimeter, a substantially horizontal flat bottom, and side walls; a launder and a launder around the perimeter of the cell; the flotation cell an open foam surface at the top of the trough; and a foam plug shaped to direct foam in the open foam region toward the rim of the trough. The flotation cell is characterized in that the flotation cell further comprises a spray pipe for introducing slurry feed into the flotation cell. The injection tube comprises an inlet nozzle for feeding a slurry feed into said injection tube; an inlet for pressurized gas, said slurry feed being subjected to said pressurization as it is discharged from said inlet nozzle; pressurized gas; an elongate chamber, which is arranged to receive the slurry feed under pressure; and an outlet nozzle, which is configured to restrict the flow of the slurry feed from the outlet nozzle, and maintain the The slurry feed in the elongated chamber is under pressure.

According to one aspect of the present invention, a flotation line is provided. The flotation line comprises a plurality of fluidly connected flotation cells, and the flotation line is characterized in that at least one of said flotation cells is a flotation cell according to the invention.

According to another aspect of the invention, the use of a flotation line according to the invention is intended for the recovery of particles comprising valuable material suspended in a slurry.

With the invention described herein, the recovery of fines in flotation processes can be improved. The particles may, for example, comprise mineral ore particles, such as metal-containing particles.

In froth flotation of mineral ores, upgrading of concentrates involves an intermediate particle size range between 40 μm and 150 μm. Therefore, fine particles are particles with a diameter of 0 μm to 40 μm, and ultrafine particles can be considered to fall in the lower limit of the fine particle size range. Coarse particles have a diameter greater than 150 μm. In froth flotation of coal, upgrading the concentrate grade involves a median particle size range between 40 μm and 300 μm. Fine particles in coal processing are particles with a diameter of 0 μm to 40 μm, and those ultrafine particles falling in the lower limit of the fine particle size range. Coarse coal particles have a diameter greater than 300 μm.

Recovering very coarse or very fine particles is challenging because in conventional mechanical flotation cells fine particles are not easily captured by the flotation air bubbles and thus may be lost in the tailings. Typically in froth flotation, flotation gas is introduced into the flotation cells or cells via mechanical agitators. The flotation bubbles so generated have a relatively large size range (typically 0.8 mm to 2.0 mm or even larger) and are not particularly suitable for trapping particles with finer particle sizes.

This can be done by increasing the number of flotation cells in the flotation line, or by recycling previously floated material (overflow) or tailings stream (underflow) back to the start of the flotation line or to the preceding cells while improving fine particle recovery. Also for fine particles, cleaning flotation lines can be used in order to improve the recovery of fine particles. In addition, many flotation devices have been designed which employ fine flotation bubbles or even so-called microbubbles. The introduction of these smaller or microbubbles can be done before feeding the slurry into the flotation cells, i.e. the ore particles are subjected to small bubbles at feed connections etc. to promote the formation of ore particle-microbubble agglomerates, The aggregates can then be floated in a flotation cell such as a flash flotation cell or a column cell. Alternatively, small or microbubbles can be introduced directly into the flotation cell, for example by eductors utilizing cavitation. With regard to mechanical flotation cells, these types of solutions are not necessarily feasible as the turbulence caused by mechanical agitation can cause ore particles - small air bubble conglomerates before they can rise into the froth layer to be trapped in the overflow in and thus decomposes before being recycled.

A columnar flotation cell acts as a three-phase settler in which particles move downward in a hindered settling environment against the rising flow of flotation bubbles generated by ejectors located near the bottom of the flotation cell. While cylindrical flotation cells can improve recovery of finer particles, particle residence time is dependent on settling velocity, which can affect flotation of larger particles. In other words, while the flotation solutions described above can have a beneficial effect on the recovery of fine particles, the overall flotation performance (recovery of all valuable material, grade of material recovered) may be negatively affected by the recovery of larger particles. weakened by the influence.

To overcome the above-mentioned problems, so-called pneumatic flotation cells are used, in which flotation gas is introduced with the slurry feed into a high shear device (such as a downcomer or jet tube), thereby generating Smaller flotation bubbles that trap finer particles. However, such high throughput flotation cells may require vacuum generation in the jet tubes to effectively achieve the required bubble formation rate to capture the desired particles during the short time the slurry feed resides in the jet tubes.

Once having left the jet tube, the flotation bubble-particle agglomerate immediately rises towards the froth layer on the top part of the flotation cell and no further attack on the particles takes place in the part of the flotation cell down from the jet tube outlet Capture further. This may result in a substantial portion of the particles containing the desired material (mineral) simply falling to the bottom of the flotation cell and ending up as tailings, which reduces the recovery rate of the flotation cell.

However, generally so called high throughput flotation cells or Jameson cell type pneumatic flotation cells do not include any flow restriction for controlling the pressure inside the jet tube after the formation of flotation bubble-particle agglomerates has occurred. This control of the pressure is also advantageous considering the pressure at which the flotation bubbles are formed (the effect on the bubble size), and for the adjustment of the relative pressure when the flotation bubbles are to be used in the flotation cell. This control is also beneficial. In this way, aggregation of air bubbles after their formation can be minimized. This is particularly advantageous because the rate at which particles are captured by the bubbles of flotation decreases as the size of the bubbles increases (assuming the ratio of air to liquid remains the same).

Additionally, so-called high throughput flotation cells can be used in coal dissociation operations where there is usually a flotation line comprising one or two such flotation cells at the end of the dissociation circuit Pools are selected for the recovery of particularly fine coal particles. In the dissociation circuit, the treated water recirculation system circulates water from the end part of the circuit (ie from the flotation line and dewatering circuit) back to the previous circuit (starting point of the dissociation circuit). Flotation chemicals, especially frothers, often cause problems in the processing ahead of the flotation line. The problem can be alleviated to some extent by minimizing the use of frother in the flotation line, but if not enough frother is added to the flotation process, the Foam formation can be poor, leading to unstable process conditions in the flotation cells and particularly unstable jet tube operation and froth layers, which in turn negatively affects the recovery of desired particles, especially coarse particles. As the bubble size increases with lower blowing agent dosage, the recovery of particles throughout the particle size distribution of the slurry is affected, especially the recovery of coarse particles.

In prior art jet tubes, the flotation gas is introduced in a self-priming manner due to the vacuum created in the downcomer. The residence time of the flotation air to be carried into the slurry is very short (3 to 5 seconds), so the system is very sensitive to process variations. The constant addition of blowing agent is required to overcome the limiting effect on the air flow required to maintain or even increase the vacuum inside the downcomer in order to keep the conditions as constant as possible for the bubble-particle engagement because the blowing agent prevents the bubbles from coalescing and Rise back into the unfilled air space inside the jet tube that is not filled with slurry. However, adding the amount of foaming required to stably use prior art downcomers creates problems in other parts of the process, particularly in coal operations, as described above. Therefore, the solution is to reduce the dosage of blowing agent, which negatively affects downcomer vacuum, bubble formation, and bubble size and surface area, and significantly reduces the recovery of desired particles, making the high throughput known in the prior art Quantitative flotation cells are inefficient in this application.

By using a flotation cell according to the invention, the amount of frother required to optimize the flotation process can be significantly reduced without significantly compromising bubble formation, bubble-particle bonding, stable froth layer formation, or the desired Material recycling. At the same time, problems associated with recirculating treated water from a downstream circuit to a preceding circuit can be alleviated. The jet tubes operating under pressure are completely independent of the flotation cells. A better flow of flotation gas can be obtained and smaller bubbles can be generated and the use of frother can be optimized since the operation of the jet tube is not dependent on the frother dosage.

In the solutions known from the prior art, the problem relates in particular to the limitation of the quantity of flotation gas that can be supplied relative to the quantity of liquid flowing through the downcomer, and to the relatively high concentration of bubbling in order to generate small bubbles. additives or other expensive surfactants. With the invention presented herein, by reducing the size of the flotation gas bubbles introduced into the slurry feed into the jet tube, by increasing the flotation gas supply rate relative to the flow rate of the particles suspended in the slurry, and by increasing The shear strength or energy dissipation rate in or near the jet tube can improve the flotation of fine and ultrafine particles containing eg mineral ores or coal. Finer particles have an increased likelihood of attaching to or being trapped by smaller flotation cells and the recovery of desired materials such as minerals or coal is improved. In the flotation cell according to the invention, sufficiently small flotation air bubbles (so-called ultrafine air bubbles) can be generated to ensure effective capture of fine ore particles. Typically, ultrafine cells may have a cell size distribution of 0.05 mm to 0.7 mm. For example, reducing the average flotation bubble size to a diameter of 0.3mm to 0.4mm means that the number of bubbles in ^1m3 of slurry can be as high as 30 million to 70 million and the total average surface area of the bubbles can be as high as ^15m2 to 20m ² . In contrast, with an average cell size of approximately 1 mm, the number of cells in 1 m ² of slurry is approximately 2 million and the total average surface area is 6 m ² . Thus, in the flotation cell according to the invention a 2.5 to 3 times higher air bubble surface area can be achieved than in the flotation cell according to prior art solutions. It goes without saying that the effect of this increase in the surface area of the gas bubbles in the recovery of particles containing valuable material is significant.

At the same time, recovery of coarser particles can be kept at an acceptable level by obtaining a high flotation gas fraction in the slurry and by having no areas of high turbulence in the region below the froth layer. That is, the known advantages of mechanical flotation cells can be utilized even though there may not necessarily be any mechanical agitation in the flotation cell. Also, the upward movement of the slurry or slurry within the flotation cell increases the likelihood that the coarser particles will rise with the flow of the slurry towards the froth layer.

One of the effects that can be obtained by the present invention is to increase the depth or thickness of the foam layer. A thicker froth layer contributes to higher grades and improves the recovery of smaller particles and allows for the elimination of a separate froth washing step typically used in column flotation cells.

By arranging a plurality of jet tubes in the flotation cell according to the invention, the probability of collisions between flotation air bubbles and between air bubbles and particles can be increased. Having multiple jet tubes ensures improved distribution of the flotation gas bubbles within the flotation cell and that the gas bubbles leaving the jet tubes are evenly distributed throughout the cell, with the distribution areas of the individual jet tubes having the possibility of intersecting and converging with each other , thereby promoting a broad and uniform distribution of the flotation bubbles within the flotation cell, which in turn can beneficially affect the recovery of especially smaller particles and also contribute to the aforementioned uniform and thick froth layer. When multiple jet tubes are present, collisions between flotation bubbles and/or particles in the slurry feed from different jet tubes are facilitated as the different streams mix and create localized mixing sub-regions. As the collision increases, more bubble-particle agglomerates are created and trapped into the foam layer, thus improving the recovery of valuable materials.

Hydrophobic particles can be introduced into the froth layer and into the flotation cell by generating fine or ultrafine flotation bubbles, by contacting the bubbles with the particles, and by controlling the flotation bubble-particle aggregate-liquid mixture of the slurry Recovery in the overflow or concentrate is maximized, thereby increasing the recovery of the desired material regardless of the particle size distribution of the desired material within the slurry. High grade can be achieved for a portion of the slurry stream while high recovery can be achieved for the entire slurry flow through the flotation line.

By arranging the outlet nozzles of the jet tubes at a suitable depth, ie at a certain vertical distance from the rim of the launder, the distribution of the flotation bubbles can be optimized in a uniform and constant manner. Since the residence time of the air bubbles in the mixing zone can be kept high enough by the proper depth of the jet tube outlet nozzle, the air bubbles can effectively contact and attach to the fine particles in the slurry, improving the recovery of smaller particles, and Also promotes froth depth, stability and uniformity at the top of the flotation cell.

By mixing zone is meant herein the vertical portion or section of the flotation cell where effective mixing of particles suspended in the slurry with flotation air bubbles takes place. In addition to such mixing zones formed throughout the vertical section of the flotation cell, separate and localized separate mixed subregions of . This can further facilitate the contact between the flotation gas bubbles and the particles, thereby increasing the recovery of valuable particles. Also, this additional mixing can eliminate the need for a mechanical mixer to suspend the solids in the slurry.

By settling zone is meant the vertical portion or section of the flotation cell in which particles not associated with the flotation bubbles or otherwise unable to rise towards the froth region on the top portion of the flotation cell are directed towards the flotation cell The bottom of the stream falls and settles to be removed in the tailings as an underflow. The settling zone is below the mixing zone.

By locating the tailings outlet at the side wall of the flotation cell, the underflow can be removed at the area where most of the slurry comprises particles that descend or settle towards the bottom of the flotation cell. In the flotation cell according to the invention, the settling zone is deeper near the side walls of the flotation cell. At such regions, the mixing action and turbulence generated by the jet tubes do not affect the settled particles, most of which do not contain any or only very small amounts of valuable material. It is also at this section that settling is most pronounced since there is no turbulence to interfere with the descent of the particles under the force of gravity. In addition, the friction created by the side walls of the flotation cells further reduces turbulence and/or flow. Therefore, taking the underflow from the flotation cell at a location arranged on such a relatively calm settling area ensures that as few particles as possible are removed from the flotation cell containing valuable material - which should instead be floated , or if for some reason it ends up in the settling zone, it should be recirculated as slurry feed through the jet tube back into the flotation tank. Furthermore, by removing the underflow from the settling area near the side walls of the flotation cell, the entire volume of the flotation cell can be efficiently utilized - there is no need to construct a separate lower settling area below the jet tube, as is the case in e.g. Jameson cells . In some embodiments, it is even foreseeable that the volume of the flotation cell may be reduced in the center of the flotation cell, thereby reducing the settling zone where turbulence caused by the slurry feed from the jet tube may affect the particles The volume of the possibility of settling towards the bottom of the flotation cell and allows the full utilization of the volume of the flotation cell. For example the volume of the flotation cell can be reduced at the center of the flotation cell by arranging a bottom structure at the bottom of the flotation cell at the center of the flotation cell. In addition, it is possible to arrange the injection pipes (outlet nozzles) relatively deep in the flotation cell, but still ensure a sufficiently calm settling area at the side walls of the flotation cell. This also further facilitates efficient utilization of the entire volume of the flotation cell.

By using the invention described herein, it is possible to more efficiently and reliably direct so-called "fragile froth" towards the froth overflow lip and froth catch chute, i.e. comprising the usual A loosely textured froth layer of larger flotation cells. Fragile foams can break easily because the cell-ore particle aggregates are less stable and have reduced toughness. This froth or froth layer cannot readily sustain the transport of ore particles, especially the coarser particles, towards the froth overflow edge to be caught in the launder, thus causing the particles to fall back into the flotation cell or slurry within the flotation cell or slurry, and reduce recovery of desired materials. Fragile foam is generally associated with low mineralization, i.e. air bubbles with a limited amount of ore particles containing the desired minerals that have been able to attach to the air bubbles during the flotation process within the flotation cell or flotation cells - Agglomerates of ore particles. This problem is especially evident in large flotation cells or flotation cells with large volume and/or large diameter. With the present invention, foam can be jammed and directed towards the foam overflow lip to reduce the foam transport distance (and thus reduce the risk of falling back) while maintaining or even reducing the overflow lip length. In other words, the handling and guiding of the froth layer in the froth flotation cell or flotation tank can be made more efficient and straightforward.

It is also possible to improve froth recovery, thus especially in later stages of the flotation line (for example in the roughing and/or scavenging stages of the flotation process) from fragile froth in large flotation cells or flotation cells Recover valuable mineral particles.

Furthermore, with the invention described herein, the area of froth on the surface of the slurry inside the flotation cell can be reduced in a robust and simple mechanical manner. At the same time, the total overflow lip length in the froth flotation cell can be reduced. In this case, robustness is considered to mean structural simplicity and durability. By reducing the froth surface area of the flotation cell by froth plugs rather than adding additional froth collection launders, the froth flotation cell as a whole can be of simpler construction, e.g. because there is no need to direct the trapped froth and/or The overflow leaves the added plug. In contrast, the captured overflow would have to be tapped from an additional launder, which would increase the constructional components of the flotation cell.

Especially in the downstream end of the flotation line, the amount of desired material that can be trapped into the froth within the slurry can be very low. In order to capture this material from the foam layer into the foam capture launder, the foam surface area should be reduced. By arranging the froth plugs in the flotation cell, the open froth surface between the froth overflow edges can be controlled. A plug may be used to direct or guide the upwardly flowing slurry within the flotation tank closer to the froth overflow lip of the froth catch launder, thereby enabling froth formation very close to the froth overflow lip or enabling all The froth is easier to form, which increases the capture of valuable ore particles. Foam plugs can also affect the overall incorporation of flotation bubbles and/or bubble-ore particle agglomerates in the froth layer. For example, if the bubble and/or bubble-ore particle agglomeration flow is directed towards the center of the flotation cell, foam plugs can be utilized to increase the froth area at the periphery of the flotation cell and/or closer to any desired The foam area of the foam overflow lip. Additionally, the open froth surface can be reduced relative to the overflow lip length, thereby improving recovery efficiency in froth flotation cells.

The flotation cell, and flotation line and use thereof according to the invention have the technical effect of allowing flexible recovery of various particle sizes and efficient recovery of mineral-containing ore-containing raw materials from initially relatively low amounts of valuable minerals Ore grains of valuable minerals. The advantages offered by the structure of the flotation line allow precise adjustment of the structural parameters of the flotation line according to the target valuable material at each device.

By treating the slurry according to the invention as defined in this disclosure, the recovery of particles containing valuable material can be increased. The initial grade of recovered material may be lower, but the material (ie slurry) is thus also readily ready for further processing (which may include, for example, regrinding and/or cleaning).

In this disclosure, the following definitions are used with respect to flotation.

Basically, flotation aims to recover a concentrate containing ore particles containing valuable minerals. By concentrate it is meant herein the portion of the slurry recovered in the overflow or underflow drawn from the flotation cells. By valuable mineral is meant any mineral, metal or other material of commercial value.

Flotation refers to phenomena related to the relative buoyancy of objects. The term flotation includes all flotation techniques. Flotation may be, for example, froth flotation, dissolved air flotation (DAF) or induced gas flotation. Froth flotation is a process used to separate hydrophobic material from hydrophilic material by adding a gas such as air or nitrogen or any other suitable medium to the process. Froth flotation can be performed based on natural hydrophilic/hydrophobic differences or based on hydrophilic/hydrophobic differences obtained through the addition of surfactants or collector chemicals. Gas can be added to the flotation feedstock object (slurry or pulp) in a number of different ways.

Flotation cells are used to process mineral ore particles suspended in a slurry by flotation. Thus, ore particles containing valuable metals are recovered from the ore particles suspended in the slurry. By flotation line is meant herein a flotation device in which a plurality of flotation cells are arranged in fluid connection with each other such that the bottom flow of each preceding flotation cell is introduced as feed to the subsequent or subsequent flotation cell , until the last flotation cell of the flotation line, from which the bottom flow is directed away from the flotation line as tailings or reject flow. The slurry is fed to the first flotation cell of the flotation line through the feed inlet to initiate the flotation process. A flotation line may be part of a larger flotation apparatus or device comprising one or more flotation lines. Thus, as is known to those skilled in the art, many different pre- and post-treatment devices or stages may be operatively connected to the components of the flotation device.

The flotation cells in a flotation line are fluidly connected to each other. Fluid connections can be made through conduits (such as pipes or tubes) of varying lengths, the length of which depends on the overall physical configuration of the flotation unit. Between the flotation cells of the flotation line, pumps or grinding/regrinding units can also be arranged. Alternatively, the flotation cells may be arranged in direct cell connection with each other. By direct cell connection is meant herein an arrangement in which the outer walls of any two consecutive flotation cells are connected to each other to allow the outlet of a first flotation cell to be connected to a subsequent cell without the aid of any separate conduit. The entrance of the flotation tank. Direct contact reduces the need for piping between two adjacent flotation cells. Thus, it reduces the need for components during construction of the flotation line, speeding up the process. Also, it reduces sanding and simplifies flotation line maintenance. The fluid connections between the flotation cells may include various adjustment mechanisms.

By "adjacent", "adjacent" or "adjacent" flotation cell, it is meant herein that the flotation cell is immediately adjacent to any flotation cell in a roughing flotation line or in a sweeping flotation line. After or before (downstream or upstream), or between the flotation cells of the rougher flotation line and the flotation cells of the sweep flotation line into which the underflow from the flotation cells of the rougher flotation line is directed relation.

By flotation cell is meant herein a tank or vessel in which the steps of the flotation process are carried out. Flotation cells are generally cylindrical in shape defined by one or more outer walls. Flotation cells generally have a circular cross-section. The flotation cells may also have polygonal (eg rectangular, square, triangular, hexagonal or pentagonal) or other radially symmetrical cross-sections. As is known to those skilled in the art, the number of flotation cells may vary depending on the particular flotation line and/or operation being used to process a particular type and/or grade of ore.

The flotation cell may be a froth flotation cell, such as a mechanically agitated type or tank cell, a cylindrical flotation cell, a Jameson cell, or a double flotation cell. In a double flotation cell, the flotation cell consists of at least two separate vessels, a first mechanically agitated pressure vessel with mixer and flotation gas input, and a second mechanically agitated pressure vessel with tailings output and overflow froth discharge. and two containers, the second container being arranged to receive the agitated slurry from the first container. The flotation cell may also be a fluidized bed flotation cell (such as a HydroFloat ^™ cell) in which air bubbles or other flotation bubbles dispersed by the fluidization system permeate through the settling hindered area and attach to the hydrophobic component, altering the composition of the hydrophobic component. density and make the hydrophobic fraction sufficiently buoyant to be floated and recovered. In fluidized bed flotation cells, axial mixing is not required. The flotation cell may also be an overflow flotation cell operating with a constant slurry overflow. In overflow flotation cells, the slurry is treated by introducing flotation air bubbles into the slurry and by creating a continuous upward flow of slurry in the vertical direction of the first flotation cell. At least a portion of the ore particles containing valuable metals attach to the air bubbles and rise by buoyancy, at least a portion of the ore particles containing valuable metals attach to the air bubbles and rise with the continuous upward slurry flow, and at least a portion of the ore particles containing valuable metals The particles rise with the continuous upward flow of slurry. Valuable metal-containing ore particles are recovered by directing a continuous upward stream of slurry as a slurry overflow from at least one overflow flotation cell. Since the isopipe operates with little to no froth depth or layer, virtually no froth zone forms on the surface of the slurry at the top portion of the flotation cell. The froth may be discontinuous over the entire flotation cell. As a result of this, more ore particles containing valuable minerals can be carried into the concentrate stream and the overall recovery of valuable material can be improved.

All the flotation cells of the flotation line according to the invention may be of a single type, namely roughing flotation cells in the roughing section, sweeping flotation cells in the sweeping section, and sweeping flotation cells of the sweeping flotation line. The selected cleaning flotation cells may be of a single type of flotation cell such that the flotation unit comprises only one type of flotation cell as listed above. Alternatively, multiple flotation cells may be of one type and others of one or more types such that the flotation line includes two or more types of flotation cells as listed above.

Depending on the type of flotation cell, the flotation cell may include a mixer for agitating the slurry to keep it in suspension. By mixer is meant herein any suitable device for agitating the slurry in the flotation cell. The mixer can be a mechanical agitator. The mechanical agitator may comprise a rotor-stator with a motor and a drive shaft, the rotor-stator structure being arranged at the bottom part of the flotation cell. The flotation cell may have auxiliary agitators arranged higher in the vertical direction of the flotation cell to ensure a sufficiently strong and continuous upward slurry flow.

By foam plug, it is meant herein a foam plug, foam baffle, or plug board, or plug board arrangement, or any other such structure or side structure (such as a sloped or vertical Straight side walls, ie plug side walls), which may also be plug side walls inside the flotation cell, ie inner peripheral plugs.

The flotation cell may comprise a bottom structure arranged on the bottom of the flotation cell with features that allow particles suspended in the slurry to mix in a mixing zone above the bottom structure and to settle in a settling zone surrounding the bottom structure. The shape of the mixing zone is created by the slurry feed flow from the outlet nozzle of the jet tube.

By arranging a bottom structure at the bottom of the flotation cell, which bottom structure extends upwards in the flotation cell, a better distribution of fine and/or small particles suspended in the slurry can be obtained. At the center of the flotation cell, the particles cannot fall and settle because the slurry feed flow from the jet tube reaches the raised center part of the flotation cell, which ensures good mixing at said raised center part . Due to the turbulent conditions in the mixing zone, particles that may have broken free from the flotation bubbles and started to descend can be recaptured by the bubbles. On the other hand, the bottom of the flotation cell closer to the periphery of the flotation cell has a sufficiently deep region that allows the unfloated, most likely worthless particles to settle and descend to be efficiently removed from the flotation cell. This settling area is not affected by the slurry feed flow from the jet tube. Also, this relatively calm zone can inhibit the formation of short streams of slurry flow within the flotation cells (where the same slurry material remains recirculated within the flotation cells without proper separation or settling). The above features can facilitate improved recovery of fine particles.

By arranging the bottom structure to have a certain size in particular with respect to the mixing zone, the mixing zone and the settling zone can be designed with the desired characteristics (size, depth, turbulence, residence time of particles in the mixing zone, non-valuable fraction Settling speed and probability in the settling area, etc.). In a traditional flotation cell, the majority of this area (without any mechanical mixing at the bottom of the flotation cell) would be subject to sanding as there is little or no mixing. If this area is filled with solids, there is a risk of this solid material collapsing and simultaneously blocking the tailings outlet and/or the recirculation outlet at the settling area.

By jet tube it is meant a double high shear device in which flotation gas is introduced into the slurry feed, thereby creating finer flotation bubbles capable of trapping also finer particles already during bubble formation in the jet tube. In particular, the jet tubes in the flotation cell according to the invention operate under pressure and do not require a vacuum.

By overflow it is meant herein the portion of the slurry that is caught in the launders of the flotation cell and thus leaves the flotation cell. The overflow may include foam, foam and slurry, or in some cases only slurry or a majority of slurry. In some embodiments, the overflow may be a receiving stream containing particles of valuable material captured from the slurry. In other embodiments, the overflow may be a reject stream. This is the case when the flotation device, apparatus and/or method is used for reverse flotation.

By underflow, it is meant herein that part or portion of the slurry that does not float into the surface of the slurry during the flotation process. In some embodiments, the bottom flow may be a reject flow that exits the flotation cell via an outlet typically arranged in the lower portion of the flotation cell. Ultimately, the bottom flow from the last flotation cell of a flotation line or flotation plant can leave the entire plant as the tailings stream or final residue of the flotation plant. In some embodiments, the underflow may be a receiving stream containing valuable mineral particles. This is the case when flotation devices, equipment and/or methods are used in reverse flotation.

The term "reverse flotation" refers herein to the reverse flotation process generally utilized in the recovery of iron. In this case, the flotation process is used to capture the non-valuable portion of the slurry stream into the overflow. The overflow used in the reverse flotation process for iron often contains silicates, while mineral particles containing valuable iron are captured in the underflow. Reverse flotation can also be used for industrial minerals, ie geological minerals mined for their commercial value (which are not sources of fuel nor metals), such as bentonite, silica, gypsum and talc.

By downstream, we mean in this paper the direction that is consistent with the slurry flow towards the tailings (forward flow, indicated by an arrow in the figure), and by upstream, we mean in this context the direction opposite to the slurry flow towards the tailings or relative direction.

By concentrate it is meant herein the flotation part or fraction of a slurry of ore particles containing valuable minerals. In normal flotation, the concentrate is the portion of the slurry that floats into the froth layer and is thus collected as overflow into the launder. The first concentrate may comprise ore particles comprising one valuable mineral and the second concentrate may comprise ore particles comprising another value mineral. Alternatively, the distinct definitions "first", "second" may refer to two concentrates of ore particles comprising the same valuable mineral but having two distinct particle size distributions.

By rougher flotation, a rougher section of a flotation line, a rougher stage and/or a rougher cell, is meant herein the flotation stage that produces the rougher concentrate. The aim is to remove the maximum amount of valuable minerals with the coarsest possible particle size. Roughing flotation does not require complete dissociation, just sufficient dissociation to release enough gangue from valuable minerals for high recovery. The main purpose of the roughing stage is to recover as much valuable minerals as possible, with less emphasis on the quality of the concentrate produced.

The rougher concentrate is usually subjected to a further cleaning flotation stage in a rougher cleaning flotation line to discard more of the undesired minerals that have been entrained to the froth in a process called cleaning. The cleaned product is called cleaned concentrate or final concentrate.

Rougher flotation is usually followed by sweep flotation applied to rougher tailings. By sweep flotation, sweep section of a flotation line, sweep stage and/or sweep cell, is meant a flotation stage in which the purpose is to recover any valuable mineral material that was not recovered during the initial roughing stage . This can be achieved by altering the flotation conditions to make them more stringent than the initial roughing, or in some embodiments of the invention, introducing microbubbles into the slurry. The concentrate from the sweep tank or stage can be returned to the rougher feed for re-flotation or directed to a re-grinding step and thereafter directed to a sweep-cleaning flotation line.

By cleaning flotation, rougher/sweep cleaning line, cleaner/cleaning stage and/or cleaning cell is meant a flotation stage in which the purpose of cleaning is to produce the highest possible concentrate grade.

By pretreatment and/or posttreatment and/or further treatment is meant eg comminution, grinding, separation, screening, classification, fractionation, conditioning or cleaning, all of which are conventional treatments known to the person skilled in the art. Further processing may also include at least one of: another flotation cell, which may be a conventional cleaning flotation cell, a recovery cell, a rougher cell, or a sweep cell.

The so-called slurry surface level herein refers to the height of the slurry surface in the flotation cell measured from the bottom of the flotation cell to the flow cell edge of the flotation cell. In practice, the height of the slurry is equal to the height of the rim of the flotation cell measured from the bottom of the flotation cell to the rim of the flotation cell. For example, any two consecutive flotation cells may be arranged in a flotation line in a stepped manner such that the slurry surface levels of such flotation cells differ (i.e., the first flotation cell in such flotation cells The slurry surface level of the cell is higher than the slurry surface level of the second flotation cell in such a flotation cell). This difference in slurry surface level is defined herein as a "step" between any two consecutive flotation cells. The step or difference in slurry surface level is to allow gravity action or gravity driven difference in slurry flow by creating a hydraulic head between two successive flotation cells.

By flotation line is meant herein a component or device comprising a plurality of flotation cells or flotation cells in which a flotation stage is carried out to form a flotation line, and the plurality of flotation cells or flotation cells The cells are arranged in fluid connection with each other to allow gravity driven or pumped slurry flow between the flotation cells. In a flotation line, several flotation cells are arranged in fluid connection with each other such that the bottom flow of each preceding flotation cell is directed as feed to the following or subsequent flotation cells up to the last flotation cell of the flotation line , the bottom flow is directed away from the flotation line from the last flotation cell as tailings or reject flow. It is also conceivable that the flotation line may comprise only one flotation stage carried out in one flotation cell or eg in two or more parallel flotation cells.

The slurry is fed to the first flotation cell of the flotation line through the feed inlet to start the flotation process. A flotation line may be part of a larger processing facility comprising one or more flotation lines, and many other processing stages for dissociation, cleaning and other processing of desired materials. Accordingly, many different pre- and post-treatment devices or devices may be operatively connected to the components of the flotation line, as is known to those skilled in the art.

By ultra-fine air bubbles it is meant herein flotation air bubbles falling in the size range of 0.05 mm to 0.7 mm which are introduced into the slurry in the jet tube. In contrast, "normal" flotation cells utilized in froth flotation exhibit a size range of approximately 0.8 mm to 2 mm. Larger flotation bubbles may have a tendency to coalesce into even larger bubbles during their stay in the mixing zone where collisions between particles and flotation bubbles and only collisions between flotation bubbles occur. Such aggregation of ultrafine air bubbles is less likely to occur since the ultrafine air bubbles are introduced into the slurry feed before it is fed into the flotation cells, and the size of the ultrafine air bubbles is The overall period in the cell can be kept small so as not to affect the ability of the ultrafine air bubbles to capture fine particles.

In an embodiment of the flotation cell according to the invention, the outlet nozzle is configured to generate a supersonic shock wave in the slurry feed, the supersonic shock wave causing the formation of flotation bubble-particle agglomerates.

Supersonic shock waves are generated when the velocity of the slurry feed through the outlet nozzle exceeds the speed of sound, that is, when the pressure ratio of the absolute pressure upstream of the outlet nozzle to the absolute pressure downstream of the throttle valve of the outlet nozzle exceeds a critical value. Flow becomes blocked. When the pressure ratio is above a critical value, the flow of the slurry feed downstream of the throttle portion of the outlet nozzle becomes supersonic and forms a shock wave. Small flotation bubbles in the slurry feed mixture are broken into even smaller bubbles due to being forced through the shock wave and are forced into contact with hydrophobic ore particles in the slurry feed, creating flotation bubbles - ore particle agglomerates . The supersonic shock waves generated in the slurry feed at the exit nozzle discharge are carried into the slurry in the flotation cell immediately adjacent to the exit nozzle, thereby also promoting the formation of flotation bubbles in the slurry outside the exit nozzle. After leaving the outlet nozzle, the fine ore particles can contact the fine flotation bubbles a second time because there are several such jet pipes/outlet nozzles that discharge into a common mixing zone where the The mixing flow of the slurry in the tube increases the possibility of secondary contact between air bubbles and particles.

In one embodiment of the flotation cell, the foam plug is a conical central foam plug arranged concentrically with the center of the flotation cell.

In another embodiment of the flotation cell, the central froth plug is arranged to plug 25 to 40% of the open froth surface.

In another embodiment of the flotation cell, the central froth plug has an included angle of 20 to 80°.

In one embodiment of the flotation cell, the foam plug is an inner peripheral plug arranged in the side wall of the flotation cell such that the lowest point of the inner peripheral plug is at a certain distance from the bottom of the flotation cell. distance.

In another embodiment of the flotation cell, the lowest point of the inner perimeter plug is at a distance from the bottom of the flotation cell that is 1/2 to 1/2 the height of the flotation cell measured as the distance from the bottom to the rim 2/3.

In another embodiment of the flotation cell, the inner perimeter plug comprises a diagonal entry opening from the lowest point, angled towards the center of the flotation cell, and between a first portion of the side wall of the flotation cell and the side The second portion of the wall extends between such that the angle of the diagonal inlet opening relative to the first portion of the side wall is 20 to 80°.

In another embodiment of the flotation cell the inner peripheral plug is arranged to plug 1/5 to 1/4 of the pulp area measured at a distance from the bottom of the flotation cell at the outlet nozzle.

In another embodiment of the flotation cell, the flotation cell includes, in addition to the inner peripheral plug, a central foam plug concentrically arranged with the center of the flotation cell.

In yet another embodiment of the flotation cell, the central froth plug is arranged to plug 25 to 40% of the open froth surface.

In another embodiment of the flotation cell, the central froth plug has an included angle of 20 to 80°.

By utilizing foam plugs in the manner described above, the foam load on the open foam surface around the central foam plug can be easily and simply balanced and controlled, and the guidance and flow of foam, especially fragile foam, can be effectively influenced. / or congestion. By foam load is meant herein the amount of foam in the open surface area in any given period of time. By pulp area is meant herein the effective open area of the flotation cell available for froth formation, as measured in the flotation cell at the height of the mixing zone, i.e. the area of the flotation cell The portion or region in the vertical direction in which the slurry is agitated or otherwise induced to mix ore particles suspended in the slurry with flotation air cells. Depending on the type of flotation cell and/or flotation cell, this mixing zone is variable.

By arranging the froth plugs at an inclination relative to the vertical of the flotation cell, flotation bubbles can be prevented from colliding and combining while still effectively reducing the froth area. This effect may be particularly advantageous when the froth plug comprises an inner peripheral plug arranged to extrude froth away from the side walls of the flotation cell. For sufficient extrusion action, the inner peripheral plug may have an inclination angle of 20-40° or even 20-80°, preferably about 30°, with respect to the vertical face of the flotation cell. Similar angles of inclination (included angles) may also be advantageous in a central foam plug for the same reason.

By arranging the central foam plug with an included angle of 20 to 80°, the foam can be squeezed out of the region where only a single injection pipe has influence, as opposed to the center of the flotation cell, In the center of the flotation cell there is abundant mixing and formation of flotation bubble-particle agglomerates due to the combined action of several jet tubes. By extrusion at areas closer to the side walls and/or the perimeter of the flotation cell, particle recovery at areas with less froth and/or fewer air bubbles can also be ensured.

In one embodiment of the flotation cell, the jet tube further comprises an impactor configured to contact the slurry feed flow from the outlet nozzle and to direct the slurry feed flow radially outward and upward from the impactor .

The impinger deflects the slurry feed flow radially outward to the side walls of the flotation cell and upwards towards the upper surface of the flotation cell (i.e. the froth layer) so small flotation bubble-ore particle agglomerates do not short flow circuit) into the tailings. All slurry feed from the jet tube is forced towards the top area of the flotation cell before gravity has a chance to impact particles not attached to the flotation cells, forcing them down and eventually entrained in the tailings stream or underflow where the foam layer rises. Thus, the possibility of short streams of particles containing valuable material can be reduced. The slurry is highly agitated by the energy of the deflected flow and forms a mixing vortex in which the size of the air bubbles can be further reduced due to the shear forces acting on the air bubbles. The high shear conditions advantageously also induce substantial contact between the flotation gas bubbles and the particles in the slurry within the flotation cell. As the slurry flow is forced upward toward the froth layer, turbulence is reduced and the flow becomes relatively uniform, which can aid in the stabilization of air bubbles that have formed, as well as in the flotation of air bubble-particle agglomerates (especially those that include coarser particles). the stability of those aggregates).

By arranging the outlet nozzle and the impactor at an optimal distance from each other, the impactor can be configured to deflect and direct the slurry feed flow radially outward and upward from the impactor to create the previously mentioned mixing within the flotation cell area, and facilitates the ascent of the particles towards the foam layer. At the same time, it may be desirable to minimize the wear on the impactor caused by the high velocity slurry flow. By positioning the outlet nozzle and the impactor in relation to each other, it is possible to optimize the flotation process in a flotation cell equipped with jet tubes and to minimize wear on the impactor components.

In one embodiment of the flotation cell, the ratio of the height of the flotation cell, measured as the distance from the bottom to the edge of the flow cell, to the diameter of the flotation cell, measured at a height from the bottom of the outlet nozzle, is from 0.5 to 1.5. In other words, the ratio of height to diameter may be 0.5 to 1.5.

In one embodiment of the flotation cell, the flotation cell has a volume of at least 20 m ³ , preferably 20 m ³ to 1000 m ³ .

By arranging the flotation cells with sufficient volume, the flotation process can be better controlled. The ascent distance to the froth layer on the top part of the flotation cell does not become too great, which can help to ensure that the flotation bubbles - ore particle agglomerates stay together up to the froth layer and can ensure less particle fall back . Moreover, a suitable bubble rising speed can be obtained to maintain a good concentrate quality. Utilization of a flotation cell of sufficient volume size to increase the probability of collisions between air bubbles generated in the flotation cell, for example by means of rotors, and particles containing valuable minerals, thereby increasing the recovery of valuable minerals, and flotation devices overall efficiency. Larger flotation cells have higher selectivity because more collisions between air bubbles and ore particles can occur due to the longer slurry residence time in the flotation cell. Thus, most of the ore particles including valuable minerals can be floated. Additionally, the fallback of buoyant ore particles may be high, meaning that ore particles containing very small amounts of valuable minerals fall back into the bottom of the flotation cell. Thus, the overflow and/or concentrate from the larger flotation cells can be of higher grade. These kinds of flotation cells ensure high grades. Furthermore, the overall efficiency of the flotation cell and/or the entire flotation line can be increased. Additionally, if the first flotation cell in the flotation line has a relatively large volume, a large subsequent flotation cell may not be required, but instead, one or more flotation cells downstream of the first flotation cell may Smaller and therefore more efficient. In the flotation process of certain minerals it may be easy to float a substantial fraction of the high grade ore particles containing valuable minerals. In this case, a flotation cell with a smaller volume can be installed downstream of the flotation line and still obtain a high recovery rate.

In one embodiment of the flotation cell according to the invention, the flotation cell comprises 2 to 40 jet tubes, preferably 4 to 24 jet tubes.

The number of jet tubes directly affects the amount of flotation gas that can be dispersed in the slurry. In conventional froth flotation, dispersing increasing amounts of flotation gas will result in increased flotation bubble size. For example, in a Jameson cell, an air-to-bubble ratio of 0.50 to 0.60 is utilized. Increasing the average bubble size will adversely affect the bubble surface area flux ( _Sb ), which means that recovery may be reduced. In the flotation cell according to the present invention, using pressurized jet tubes, significantly more flotation gas can be introduced into the process without increasing the bubble size or reducing _Sb , because in the slurry The flotation air bubbles generated in the feed are kept relatively small. On the other hand, by keeping the number of injection tubes as small as possible, the cost of retrofitting an existing flotation cell or the capital expenditure of setting up such a flotation cell can be kept under control without causing a loss in the flotation performance of the flotation cell. any loss.

In one embodiment of the flotation cell, the injection pipe is arranged concentrically with the periphery of the flotation cell at a distance from the foam plug.

The exact number of jet tubes in the flotation cell may depend on the size or volume of the flotation cell, the type of material to be collected, and other process parameters. Uniformity of ultra-small bubbles can be ensured by arranging a sufficient number of jet tubes into the flotation cell and by arranging the jet tubes in a specific manner relative to the center, perimeter and/or side walls of the flotation cell and from the froth plug distribution, and the uniform mixing effect caused by the shear force in the fixed tank.

In one embodiment of the flotation cell, the flotation cell further comprises a regulating loop.

In another embodiment of the flotation cell, the regulating circuit comprises a pump tank in fluid communication with the flotation cell, in which the slurry fraction withdrawn from the flotation cell via the outlet is fed with fresh slurry Arranged to combine as slurry feed.

In another embodiment of the flotation cell, said outlet is arranged at a side wall of the flotation cell at a distance from the bottom of the flotation cell.

In another embodiment of the flotation cell, the distance of the outlet from the bottom of the flotation cell is 0% to 50% of the height of the flotation cell.

In another embodiment of the flotation cell, the regulating circuit further comprises a pump arranged to suck the slurry portion from the flotation tank and to convey the slurry feed forward from the pump tank.

In another embodiment of the flotation cell, the regulating circuit further comprises a distribution unit arranged to distribute the slurry feed.

By taking the slurry from the bottom of the flotation cell it is ensured that the finer particles that settle to the bottom of the flotation cell can be efficiently reintroduced into the flotation cell where effective flotation takes place before said finer particles are entrained to the tailings in the selected processing section. Thus, the recovery of valuable material can be increased since particles containing even minimal amounts of valuable material can be captured into the concentrate.

The flotation process can be made more efficient when only a portion of the slurry within the flotation cell is recycled back into the same flotation cell via the jet tube as slurry feed. In particular, due to the impactors (which are designed to direct the slurry flow radially outwards and upwards to create turbulent flow conditions for the mixing zone and additional mixing sub-zones, as explained earlier) are very effective in creating - Favorable conditions for particle agglomeration and thus ensuring efficient recovery of particles containing valuable material, so there may be no need to recirculate large amounts of slurry to be processed again in the same flotation cell. Processing tailings from another flotation cell in one flotation cell may be sufficient to ensure high recovery. Due to the possibility of a short stream of particles containing valuable material entering the tailings/underflow, it may not be necessary to recirculate a portion of the slurry from the flotation cells, or it may only be necessary to recirculate a small portion of the slurry in order to recycle as such way to increase recycling.

Jet tubes and especially impactors can create favorable conditions with respect to particle recovery, and the flotation cells can be arranged to process only new slurry, ie slurry feed from previous flotation cells or previous processing steps. It may not be necessary to recirculate the slurry from the flotation cell to be processed again in the same flotation cell, but any particles comprising valuable material remaining in the portion of the slurry that descends towards the bottom of the cell can be directed for further processing lead to subsequent flotation cells and still improve the recovery of valuable materials by the present invention.

In one embodiment of the flotation line according to the invention, the flotation cell according to the invention is preceded by a flotation cell. The preceding flotation cells may be of any suitable type.

In one embodiment of the flotation line, the flotation cell according to the invention is preceded by a mechanical flotation cell.

In another embodiment of the flotation line, the flotation line comprises: a rougher section with flotation cells; a sweep section with flotation cells arranged to receive underflow from the rougher section; A scavenging cleaning section of a cell arranged to receive overflow from the scavenging section, wherein the scavenging section and/or the last flotation cell of the scavenging cleaning section is a flotation cell according to the invention.

In yet another embodiment of the flotation line, the flotation cell according to the invention is preceded by a mechanical flotation cell.

One embodiment of the use of the flotation line according to the invention is in particular for the recovery of mineral ore particles containing non-polar minerals such as graphite, sulphur, molybdenite, coal and talc.

The processing of slurries for the recovery of industrial minerals such as bentonite, silica, gypsum or talc can be improved by using reverse flotation. In the recovery of industrial minerals, the goal of flotation may be, for example, to remove dark particles into a reject overflow and recover white particles into a receiving underflow. In this treatment, some of the lighter and finer white particles may end up in the overflow. Those particles can be efficiently recovered by the invention according to the present disclosure. In reverse flotation, particles containing unwanted material are removed from the slurry by arranging gas bubbles to attach to those particles and removing them from the flotation cell in the overflow, while recovering the particles of valuable material, thus reversing conventional flotation's accept flow to overflow and reject flow to underflow. Often in reverse flotation, the large mass pull of worthless material can cause major problems in controlling the flotation process.

One embodiment of the use of the flotation line according to the invention is in particular for the recovery of particles containing polar minerals.

One example of the use of a flotation line is particularly for the recovery of particles from minerals with a Mohs hardness of 2 to 3, such as galena, sulfide minerals, PGM minerals, and/or REO minerals.

Another example of the use of flotation lines is in particular for the recovery of Pt-containing particles.

One example of the use of a flotation line is in particular for the recovery of Cu-containing particles from minerals with a Mohs hardness of 3 to 4.

Another example of the use of flotation lines is notably for the recovery of Cu-containing particles from low-grade ores.

Minerals of value may be eg Cu, or Zn, or Fe, or pyrite, or metal sulfides such as gold sulfide. According to different aspects of the invention, mineral ore particles containing other valuable minerals such as Pb, Pt, PGM (platinum group metals Ru, Rh, Pd, Os, Ir, Pt), oxide minerals, industrial minerals such as Li (ie, spodumene), petalite, and rare earth minerals.

For example, during copper recovery from low grade ore obtained from lean mineral deposits, the amount of copper may be as low as 0.1% by weight of the feed (ie the slurry feed to the flotation line). A flotation line according to the invention would be very practical for recovering copper, since copper is a so-called easily floatable mineral. During the dissociation of copper-containing ore particles a relatively high grade can be obtained from the first flotation cell of the flotation line. The recovery can be further increased by means of the flotation cell according to the invention.

By using the flotation unit according to the invention, the recovery of such small amounts of valuable minerals, such as copper, can be efficiently increased and even lean ore deposits can be utilized economically. As known rich ore deposits have been increasingly used, there is also a definite need to treat lesser minerals that may not have been exploited previously due to a lack of adequate technology and processes for recovering very low quantities of valuable material in the ore. favorable deposits.

Description of drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description help to explain the principles of the disclosure. In the attached picture:

Figure 1 is a 3D projection of a flotation cell according to an embodiment of the invention,

Figure 2 shows a flotation cell when viewed from above according to an embodiment of the invention,

Figure 3 shows a flotation cell according to an embodiment of the invention in side view,

Fig. 4 is the vertical section along section A-A of the flotation cell of Fig. 3,

Figure 5 is a schematic illustration of a flotation cell according to the invention showing in detail the dimensions of the flotation cell,

Figures 6a and 6b are schematic diagrams of flotation lines according to embodiments of the present invention,

Figure 7 shows a schematic vertical section of an embodiment of a flotation cell according to the invention, and

Fig. 8 is a schematic diagram of a form of bottom structure according to an embodiment of a flotation cell.

Detailed ways

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

The following description discloses some embodiments in detail to enable those skilled in the art to utilize the flotation cells, flotation lines and uses thereof based on the present disclosure. Not all steps of the examples are discussed in detail since many steps will be apparent to those skilled in the art based on this disclosure.

For reasons of clarity, where components are repeated, the part reference numbers will be maintained in the following exemplary embodiments.

Figures 1-5 and 7 show the flotation cell 1 in more detail. The figures are not drawn to scale and many components of the flotation cell 1 have been omitted for clarity. Figures 6a-6b show in a schematic way an embodiment of a flotation line. The direction of slurry flow is shown in the figure by arrows.

The flotation cell 1 according to the invention is intended for processing mineral ore particles suspended in a slurry and for separating the slurry into an underflow 400 and an overflow 500 comprising a concentrate of the desired mineral.

Underflow 400 is removed or tapped from the flotation cell via tailings outlet 140 . According to one embodiment, the tailings outlet 140 may be arranged at the side wall 14 of the flotation cell 10 (see FIG. 4 ). The tailings outlet 140 may be arranged at the side wall ₁₄ of the flotation cell 10 at a distance L6 from the bottom 13 of the flotation cell 10 . Said distance should be understood as the distance from the lowest point of the tailings outlet 140 or outlet opening in the side wall 14 of the flotation cell 10 to the bottom 13 of the cell. The distance L ₆ may be 1% to 15% of the height H of the flotation cell 10 . For example, distance _L6 may be 2% or 5% or 7.5% or 12% of height H. Alternatively, the tailings outlet 140 may be arranged at the bottom 13 of the flotation cell 10 (see FIG. 1 ). The tailings outlet 140 may be controlled by a dart valve or by any other suitable means known in the art to control the flow of the underflow from the flotation cell 10 . The tailings outlet 140 is ideally located at the lower portion of the flotation cell 10, i.e. close to or adjacent to the flotation cell, even if it is controlled by an internal or external structure such as an upflow or downflow dart box respectively. at the bottom 13 of the flotation cell 10, or even at the bottom 13 of the flotation cell 10. More specifically, an underflow 400 or tailings is removed from the lower portion of the flotation cell 10 , and at or near the sidewall 14 of the flotation cell 10 .

With particular reference to FIGS. 1-5 , a flotation cell 1 comprises a flotation cell 10 having a center 11 , a perimeter 12 , a bottom 13 and side walls 14 . The flotation cell 1 also comprises a launder 2 and a launder rim 21 surrounding the periphery 12 of the flotation cell 10 .

In the figures, the launder 2 is a peripheral launder. It should be understood that the launder 2 may alternatively or additionally comprise a central launder arranged at the center 11 of the flotation cell 10 as is known in the art. The rim of the center launder may face the periphery 12 of the flotation cell 10 , or face the center 11 of the flotation cell 10 , or face both the periphery 12 and the center 11 of the flotation cell 10 . The overflow 500 is captured from the froth layer formed in the upper part of the flotation cell 10 into the launder 2 or in the launders as it passes over the rim 21 . The froth layer comprises an open froth surface A _f at the top of the flotation cell 10 .

The flotation cell 10 has a height H measured as the distance from the bottom 13 of the flotation cell 10 to the rim 21 of the flow cell. At the periphery 12 of the flotation cell 10 the height H is substantially equal to or greater than the height H of the flotation cell 10 at the center 11 . In other words, the flotation cell 10 may have different vertical profiles (see FIG. 7 ), eg the side wall 14 of the flotation cell 10 may comprise at its lower part a portion inclined towards the center 11 of the flotation cell 10 .

Furthermore, the flotation cell 10 has a diameter D measured at a distance h ₁ of the outlet nozzle 43 from the bottom 13 of the flotation cell 10 . In one embodiment, the ratio H/D of the height H to the diameter D of the flotation cell 10 is 0.5 to 1.5.

The flotation cell 10 may have a volume of at least 20 m ³ . The flotation cell 10 may have a volume between ^20m3 and ^1000m3 . For example, the volume of the flotation cell 10 may be 100m ³ , or 200m ³ , or 450m ³ , or 630m ³ .

The flotation cell 10 comprises an injection pipe 4 for introducing a slurry feed 100 into the flotation cell 10 . The injection pipe 4 comprises an inlet nozzle 41 for feeding the slurry feed 100 into the injection pipe 4; an inlet 42 for pressurized air or other gas so that the slurry feed 100 can be fed from the inlet nozzle 41 air or other gas subjected to pressurization when discharged; an elongated chamber 40 arranged to receive the slurry feed 100 under pressure; an outlet nozzle 43 configured to limit the passage of the slurry feed 100 from the outlet nozzle 43 Flowing, and maintaining the slurry feed in the elongate chamber 40 under pressure.

The flotation gas is entrained by turbulent mixing caused by the jets and is dispersed into small bubbles in the slurry feed 100 as it travels down through the elongated chamber 40 to the outlet nozzle 43, so The outlet nozzle 43 is configured to restrict the flow of the slurry feed 100 from the outlet nozzle 43 and is also configured to maintain the slurry feed under pressure in the elongated chamber 40 .

According to one embodiment, the outlet nozzle 43 may also be configured to generate supersonic shock waves in the slurry feed, which cause the formation of flotation bubble-particle agglomerates. For example, outlet nozzle 43 may induce a supersonic shock wave in slurry feed 100 as it exits jet tube 40 . In addition, supersonic shock waves can extend into the slurry adjacent to or around the outlet nozzle, so that even outside the jet tube, the generation of small-sized flotation bubble-particle agglomerates is thus possible.

To restrict flow, the outlet nozzle 43 may include a restriction, such as a throat restriction. The slurry feed 100 flows under pressure into the flotation cell 10 from the outlet nozzle 43 , more specifically from the throttle valve.

As the slurry feed 100 passes through the outlet nozzle 43 or through the throttle valve of the outlet nozzle 43 , the size of the flotation bubbles decreases due to pressure changes and due to the high shear environment downstream of the outlet nozzle 43 . When the flow becomes choked, the velocity of the gas-liquid mixture in the outlet nozzle 43 or the throttle valve may exceed the speed of sound, and the flow downstream of the throttle valve becomes supersonic and forms in the bifurcated part of the outlet nozzle 43 shock wave. In other words, the outlet nozzle 43 is configured to induce supersonic shock waves in the slurry feed 100 .

When the pressure ratio of the absolute pressure upstream of the outlet nozzle 43 to the absolute pressure downstream of the restriction of the outlet nozzle 43 exceeds a critical value, the flow of the slurry feed 100 becomes obstructed. When the pressure ratio is above a critical value, the flow of the slurry feed 100 downstream of the restriction of the outlet nozzle 43 becomes supersonic and forms a shock wave. The small flotation bubbles in the slurry feed 100 mixture are broken up into even smaller bubbles due to being compressed by the shock wave and are forced into contact with the hydrophobic ore particles in the slurry feed 100, thereby creating flotation bubbles - ore particles aggregates.

Outlet nozzles 43 may be disposed within the flotation cell 10 at a desired depth. The outlet nozzle 43 may be positioned at a vertical distance _L5 from the rim 21 of the launder, a distance _L5 of at least 1.5 m. In other words, the length of the part of the jet tube 4 which is arranged inside the flotation cell 10 below the level of the flow cell lip 21 is at least 1.5 m. In one embodiment, the distance L ₅ is at least 1.7 m and the distance h ₁ of the outlet nozzle 43 from the bottom 13 of the flotation cell 10 is at least 0.4 m. For example, distance _L5 may be 1.55m, or 1.75m, or 1.8m, or 2.2m, or 2.45m, or 5.25m; and regardless of distance _L5 , distance _h1 may be 0.45m, 0.55m, 0.68m , 0.9m or 1.2m. Also, the ratio of the distance _L5 to the height H of the flotation cell 10 may be 0.9 or less. The depth at which the jet tubes 4 are arranged in the flotation cell 10 may depend on many factors, for example on the properties of the slurry and/or valuable minerals to be treated in the flotation cell 1, or on the flotation water in which the flotation is arranged. Select the configuration of the flotation line for cell 1. The ratio h ₁ /H of the distance h ₁ of the outlet nozzle 43 from the bottom 13 of the flotation cell 10 to the height H of the flotation cell 10 may be 0.1 to 0.75.

The diameter of the outlet nozzle 43 may be 10% to 30% of the diameter of the elongated chamber 40 of the injection pipe 4 . The outlet nozzle 43 may have a diameter of 40 mm to 100 mm. For example, the diameter of the outlet nozzle 43 may be 55 mm, or 62 mm, or 70 mm.

By arranging the outlet nozzles to have a certain diameter, the velocity of the slurry feed can be maintained at a level that favors the creation of small sized flotation bubbles and the likelihood of these bubbles coming into contact with the ore particles in the slurry. In particular, in order to maintain the shock wave after the exit nozzle, it is necessary to maintain a slurry velocity of 10 m/s or higher. The effect of slurry feed flow in different types of flotation cells can be accounted for by designing the outlet nozzles relative to the jet tube size.

Injection tube 4 may also include an impactor 44 configured to contact the flow of slurry feed 100 from outlet nozzle 43 and to direct the flow of slurry feed 100 radially outward and upward from the impactor 44 . The slurry feed 100 exiting the outlet nozzle 43 is thus directed into contact with the impactor 44 . The distance L ₃ from the bottom 440 of the impactor 44 to the outlet nozzle 43 may be 2 times to 20 times the diameter of the outlet nozzle 43 . For example, the distance L ₃ may be 5 times, 7 times, or 12 times, or 15 times the diameter of the outlet nozzle 43 .

The ratio L ₃ /h ₁ of the distance L ₃ to the distance h ₁ of the outlet nozzle 43 from the bottom 13 of the flotation cell 10 may be lower than 1.0. Furthermore, the distance h ₃ of the bottom 440 of the striker 44 from the bottom 13 of the flotation cell 10 may be at least 0.3 m. For example, the distance h ₃ may be 0.4m, or 0.55m, or 0.75m, or 1.0m.

The impactor 44 may include an impact surface for contacting the flow of slurry feed 100 exiting the outlet nozzle 43 . Impact surfaces can be made of wear-resistant materials to reduce the need for replacement or repair.

The slurry (which is essentially a gas-liquid two-phase mixture) rising from the impactor 44 enters the upper portion of the flotation cell 10, and the flotation gas bubbles rise and separate from the liquid to form a froth layer. The froth rises and discharges as overflow 500 over the rim 21 into the launder 2 and out of the flotation cell 1 . Tailings or underflow 400 from which the desired material has been substantially removed exits the flotation cell 10 through an outlet arranged at or near the bottom 13 of the flotation cell 10 .

Some of the coarse hydrophobic particles entrained into the froth may then separate from the flotation air cells and fall back into the flotation cell 10 due to the coalescence of the bubbles in the froth. However, most of these particles fall back into the flotation cell 10 in such a way and position that they can be captured by air bubbles newly entering the flotation cell 10 from the jet tube 4 and carried again into the froth layer.

In the flotation cell 1, 2-40 spray pipes 4, or 4-24 spray pipes 4 can be arranged. In one embodiment, there are 16 injection pipes 4 . In another embodiment, there are 24 injection pipes 4 . In another embodiment, there are 8 injection pipes 4 . The exact number of jet tubes 4 may depend on the particular operation (e.g. the type of slurry being processed in the flotation cell 1, the volumetric feed flow to the flotation cell 1, the mass throughput to the flotation cell 1, Or the volume or size of the flotation cell 10) and select. In order to properly distribute the flotation gas into the flotation cell 10, 4 to 6 injection pipes 4 may be used.

The injection pipe 4 can be arranged concentrically with the periphery 12 of the flotation cell 10 at a distance from the center 11 of the flotation cell 10 . This may be the case when the cross-section of the flotation cell 10 is circular. The spray tubes 4 can also be arranged such that each spray tube 4 is located at a distance L ₁ from the outlet nozzle 43 to the center 11 of the flotation cell 10 , said distance being preferably equal for each spray tube 4 . For example, the distance L ₁ may be 10% to 40% of the diameter D of the flotation cell 10 . According to different embodiments of the flotation cell 1 , the distance L ₁ may be 12.5%, or 15%, or 25% or 32.5% of the diameter D of the flotation cell 10 .

The injection pipe 4 can be arranged parallel to the side wall 14 of the flotation cell 10 at a distance from the side wall 14 . This may be the case when the cross-section of the flotation cell 10 is rectangular. The distance L ₂ of the outlet nozzle 43 of the spray pipe 4 from the side wall 14 of the flotation cell 10 may be 10% to 40% of the diameter D of the flotation cell 10 . In one embodiment, the distance L ₂ is 25% of the diameter D of the flotation cell 10 . According to different embodiments of the flotation cell 10 , the distance L ₂ may be 12.5%, or 15%, or 27% or 32.5% of the diameter D of the flotation cell 10 . In addition, the spray pipes 4 arranged in parallel can also be arranged in a straight line in the flotation cell 10 .

Furthermore, in all the above-described embodiments, the injection pipes 4 may be arranged at equal distances from each other, so that the distance between any two adjacent outlet nozzles 43 is the same.

The slurry fraction 300 can be withdrawn from the flotation cell 10 via an outlet 31 arranged at the side wall 14 of the flotation cell 10 . This slurry portion 300 is recycled into the injection pipe 4 as feed slurry. In one embodiment, the slurry feed 100 includes 40% or less of the slurry fraction 300 . In one embodiment, the slurry feed 100 includes 50% or less of the slurry fraction 300 . For example, the slurry feed may comprise 5%, or 12.5%, or 20%, or 30%, or 45% slurry portion 300 . Alternatively, the slurry feed 100 may comprise a 0% slurry fraction 300, i.e. the slurry withdrawn from the flotation cell 10 is not recycled back into the flotation cell, but the slurry feed 100 comprises 100% New slurry 200, for example from a previous flotation cell (ie from the underflow 400 of the previous flotation cell) or from a previous processing step.

The slurry fraction 300 may be recycled to all jet tubes 4 of the flotation cell 10, or alternatively to some jet tubes 4, while other jet tubes 4 receive new slurry 200 comprising previously Depending on the position of the flotation cell 1 within the flotation line 8, the bottom flow 400 of the flotation cell or the slurry flow from some previous processing step. The outlet 31 may be arranged at a distance L ₄ from the bottom 13 of the flotation cell 10 . Said distance should be understood as the distance of the lowest point of the outlet or outlet opening in the side wall 14 of the flotation cell 10 from the bottom 13 of the cell. The distance L ₄ is 0% to 50% of the height H of the flotation cell 10 . The outlet 31 may advantageously be positioned at a settling zone where particles suspended in the slurry but not captured by the flotation air bubbles and/or the upward slurry flow descend towards the bottom 13 of the flotation cell 10 . In one embodiment, the outlet 31 is arranged at the lower part of the flotation cell 10 . For example, the distance L ₄ may be 2%, or 8%, or 12.5%, or 17%, or 25% of the height H of the flotation cell 10 . Even if the outlet 31 is controlled by an internal or external structure such as an upflow or downflow dart box, the outlet 31 is ideally located at the lower portion of the flotation cell 10, ie near or adjacent to the bottom 13 of the flotation cell. More specifically, the slurry portion 300 is removed from the lower portion of the flotation cell 10 .

The flotation cell 10 further comprises a froth plug 6 shaped to direct the froth in the open froth surface _Af towards the flow cell lip 21, or to direct the rising flotation fluid towards the froth layer 5 at the open froth surface _Af . Air bubbles - flow of ore particle agglomerates (see in particular Figure 4). The foam plug 6 may be a central foam plug 61 or an inner peripheral plug 62 arranged in the flotation cell 10 at a desired depth at the side wall 14 of the flotation cell 10 Inside.

The central foam plug 61 is arranged concentrically to the center 11 of the flotation cell 10 . The central foam plug 61 may have a conical or frusto-conical shape. The central foam plug 61 may have a pyramidal or truncated pyramidal shape. In other words, the vertical section of the central foam plug 61 may be an inverted triangle with the apex pointing towards the bottom 13 of the flotation cell. If the central foam plug 61 has a truncated structure or shape, the apex is only functional, i.e., it will be considered the lowest point of the structure or shape as it continues to the full untruncated form, given by This can identify the included angle α regardless of the actual shape or form of the central foam plug. The included angle α may be 20 to 80°. For example, the included angle α may be 22°, or 37.5°, or 45°, or 55°, or 63.75°, or 74°. In one embodiment, the central foam plug 61 is arranged to plug 25 to 40% of the open foam surface _Af .

As an alternative or in addition to the central foam plug 61, the flotation cell may include an inner peripheral plug 62 arranged in the side wall 14 of the flotation cell 10 such that the lowest point 620 of the inner peripheral plug is at a distance from The bottom 13 of the flotation cell 10 is at a distance _h2 . The distance h ₂ may be 1/2 to 2/3 of the height H of the flotation cell 10 . The inner perimeter plug 62 may be formed to include a diagonal entry opening 14c from the lowest point 620, angled towards the center 11 of the flotation cell 10, and between the first portion 14a of the side wall 14 of the flotation cell 10 and the The second portion 14b of the side wall 14 extends between such that the angle of inclination β of the diagonal inlet opening 14c relative to the first portion 14a of the side wall 14 is 20 to 80°. The inclination angle β may be, for example, 22°, or 37.5°, or 45°, or 55°, or 63.75°, or 74°. The inner peripheral plug 62 may be arranged to block 1/5 to 1/4 of the pulp area _Ap at the mixing zone A at a distance _h1 from the bottom 13 of the flotation cell 10 at the outlet nozzle 43 of the injection pipe 4 Measure the slurry area A _p at . The mixing zone A (i.e., the vertical portion or region of the flotation cell in which the slurry is agitated or otherwise induced to mix the ore particles suspended in the slurry with the flotation air bubbles) generally surrounds the jet tube The lower part of 4 and the impingement bowl 44 are formed at the vertical part of the flotation cell 10 (see FIG. 5 ).

In addition, the flotation cell 10 may further include a bottom structure 7 (see FIGS. 5 and 7 ), which is arranged on the bottom 13 and has a shape that allows particles suspended in the slurry to form on the bottom structure. Mixing in the mixing zone A above 7 and settling in the settling zone surrounding the bottom structure 7.

The shape of the bottom structure 7 can be defined as follows (see FIG. 8 ): the vertical section of the bottom structure can be understood as taking the form of a functional triangle 700 comprising A first (top) apex 71 ; a second apex 71 a ; and a third apex 71 b are arranged at the bottom 13 of the flotation cell 10 . The first side a is formed between the first vertex 71 and the second vertex 71a. The second side b is formed between the first vertex 71 and the third vertex 71b. The base c is formed between the second apex 71a and the third apex 71b, the base c is thus parallel to and on the bottom 13 of the flotation cell 10 . The central axis 70 of the functional triangle 700 is approximately concentric with the center 11 of the flotation cell 10 . In this context, "approximately" should be understood as possible that a slight deviation from the center 11 of the flotation cell 10 may naturally occur during manufacture and/or installation of the bottom structure 7 . However, it is intended that the two axes, namely the central axis 70 of the functional triangle (which is also the central axis of the bottom structure 7 ) and the central axis of the flotation cell 10 , be coaxial.

The base angle α between the first side a and the base c (and/or between the second side b and the base c) with respect to the bottom 13 of the flotation cell 10 is 20° to 60°. For example, angle α may be 22°, or 27.5°, or 35°, or 45°, or 53.75°. Moreover, the angle β between the first side a and the second side b is 20° to 100°. Preferably, the included angle β is 20° to 80°. For example, the included angle β may be 22°, or 33.5°, or 45°, or 57.75°, or 64°, or 85.5°. Thus, the functional triangle can be an isosceles triangle or an equilateral triangle.

A functional triangle is essentially a form that can be determined by the above-mentioned features regardless of the actual form of the bottom structure 7, which can be e.g. conical, truncated, depending on the cross section and other structural details of the flotation cell 10. Conical, pyramidal, or truncated pyramidal. A conical or frusto-conical shape may be a suitable form for a flotation cell with a circular cross-section. Pyramidal or truncated pyramidal may be suitable forms for flotation cells with rectangular cross-section.

The bottom structure 7 comprises a base 73 corresponding to the base c of the functional triangle 700 (i.e. the base c of the functional triangle 700 defines the base 73 of the bottom structure 7) and is arranged on the bottom 13 of the flotation cell 10 . Furthermore, the bottom structure includes a cover 72 . The shroud 72 is defined at least by the first vertex 71 , the second vertex 71 a and the third vertex 71 b of the functional triangle 700 . Thus, regardless of the actual form of the substructure 7 , the functional triangle 700 defines the extreme physical dimensions of the substructure 7 . For example, in case the bottom structure 7 has an irregular form but is still rotationally symmetrical, the bottom structure 7 will fit entirely into a functional triangle 700 (see last ray of FIG. 8 ). In one embodiment, the cover 72 is at least partially defined by a first side a and a second side b of a functional triangle. An example of such an embodiment is a bottom structure 7 having a frusto-conical form (see middle diagram of FIG. 8 ). In one embodiment, the cover 72 is substantially completely delimited by the first side a and the second side b of the functional triangle 700 , ie the bottom structure 7 has a conical form (see first diagram of FIG. 8 ).

The bottom structure 7 has a height h ₄ measured from the highest part of the bottom structure 7 to the bottom 13 of the flotation cell 10 . The highest part is also the first vertex 71 of the functional triangle 700 if the bottom structure is in the form of a cone or a pyramid. If the bottom structure 7 has a certain truncated form, the height h ₄ is measured from the horizontal top of the truncated form (see middle diagram of FIG. 8 ) to the bottom 13 of the flotation cell 10 . The height _h4 is greater than 1/5 and less than 3/4 of the height H of the flotation cell 10 . Further, the diameter d ₃ of the base 73 of the bottom structure 7 may be 1/4 to 3/4 of the diameter d ₁ of the bottom 13 of the flotation cell 10 . If the flotation cell 10 and/or the bottom structure 7 have a non-circular cross-section, the diameter is measured as the largest diagonal of the corresponding part (base 73 and bottom 13). In one embodiment, the surface area of the base 73 of the bottom structure 7 is less than 80% of the surface area of the bottom 13 of the flotation cell 10 . The surface area of the substrate 73 may be 25% to 80% of the surface area of the bottom 13 of the flotation cell 10 .

Furthermore, the volume of the flotation cell 10 occupied by the bottom structure 7 may be 30% to 70% of the volume of the flotation cell 10 occupied by the mixing zone A.

The bottom structure 7 may additionally comprise any suitable support structure and/or connection structure on the bottom 13 of the flotation cell 10 for mounting the bottom structure 7 into the flotation cell 10 . The bottom structure 7 may be made of any suitable material such as metal (eg stainless steel).

The flotation cell 1 can also comprise a regulating circuit 3 . The regulating circuit 3 may comprise a pump tank 30 or other such additional vessel in fluid communication with the flotation tank 10 . In the pump tank 30 , the slurry fraction 300 withdrawn from the flotation cell 10 via the outlet 31 and the feed of fresh slurry 200 are arranged to be combined into a slurry feed 100 . The new slurry 200 can be, for example, the underflow 400 from the previous flotation cell, or if the flotation cell 1 is the first flotation cell of the flotation line, the slurry from the grinding unit/step or the sorting unit/step. material. It is also possible that the slurry portion 300 and the fresh slurry 200 are dispensed into the injection pipe 4 without first being combined in the pump tank 30 .

The combined slurry may be recycled to all jet tubes 4 of the flotation cell 10, or alternatively to some jet tubes 4, while others receive new slurry 200 comprising previously floated Depending on the position of the flotation cell 1 within the flotation line 8, the bottom flow 400 of the cell is either the slurry flow from some previous processing step.

The outlet 31 may be arranged at the side wall 14 of the flotation cell 10 at a distance L ₄ from the bottom 13 of the flotation cell 10 . The distance L ₄ may be 0% to 50% of the height H of the flotation cell 10 . For example, the distance L ₄ may be 2%, or 8%, or 12.5%, or 20%, or 33% of the height H of the flotation cell 10 .

In addition, the regulating circuit may comprise a pump 32 arranged to suck the slurry fraction 300 from the flotation tank 10 and to convey the slurry feed 100 forward from the pump tank 30 to the injection pipe 4 . Slurry fraction 300 may include particles having a low settling velocity, such as slow-floating fine particles. The slurry portion may be withdrawn from the bottom of the flotation cell 10 or from near the bottom of the flotation cell 10 . Additionally or alternatively, the regulating circuit 3 may also comprise a distribution unit (not shown in the figures) arranged to distribute the slurry feed 100 into the injection pipe 4 . The pump 32 can also be used to forward the slurry feed 100 into the injection pipe 4 . In order to distribute the slurry feed 100 evenly into the injection pipes 4, a distribution unit can be utilized. The distribution unit may, for example, comprise a feed conduit inside the flotation cell 10 configured to distribute the slurry fraction 300 directly into the injection pipe 4 . For example, the distribution unit may comprise a conduit arranged outside the flotation cell 10 leading to a separate feed distributor configured to distribute the slurry fraction 300 or the slurry fraction 300 and fresh slurry 200 The combination is dispensed into the injection pipe 4.

According to another aspect of the invention, a flotation line 8 is shown in Figures 6a and 6b. The flotation line 8 comprises a plurality of fluidly connected flotation cells 1a, and at least one of the flotation cells is the flotation cell 1 of the above-described embodiment of the flotation cell 1 according to the invention. In one embodiment of the flotation line 8, the flotation cell 1 according to the invention is preceded by a flotation cell 1a. The flotation cell 1a may be of any type known in the art. Alternatively or additionally, the flotation cell 1 may be preceded by a mechanical flotation cell 1b (see Fig. 6a).

In one embodiment of the flotation line 8, the flotation line 8 comprises a roughing section 81 with the flotation cells 1a; a sweeping section 82 with the flotation cells 1a arranged to receive the underflow from the roughing section 81 400; and a scavenging cleaning section 820 with the flotation cell 1a arranged to receive the overflow 500 from the scavenging section 82 (see Fig. 6b). In the flotation line 8, the last flotation cell 1 of the scavenging section 82, and alternatively or additionally the last flotation cell 1 of the scavenging section 820, is a flotation cell 1 with jet tube 4 according to the invention. Choose pool 1. In addition, in the flotation line 8, the flotation cell 1 with jet tube 4 according to the invention may be preceded by a mechanical flotation cell 1b, as described above.

The flotation line 8 may be preceded by other treatments such as grinding, sorting, screening, dense media treatment, coarse particle recovery treatment, spiraling, and other separation treatments; and other flotation treatments. The flotation line 8 can be followed by various treatments such as regrinding, cleaning or other flotation treatments, centrifugation, filtration, screening or dewatering.

According to another aspect of the invention, the flotation line 8 may be used to recover particles containing valuable materials suspended in the slurry. In one embodiment, the use may involve recovery of particles containing non-polar minerals (eg, graphite, sulfur, molybdenite, coal, talc).

According to another embodiment, the use may involve the recovery of particles containing polar minerals.

In another embodiment, the use involves recovering particles from minerals with a Mohs hardness of 2 to 3, such as galena, sulfide minerals, PGM, and/or REO minerals. In yet another embodiment, the use specifically relates to the recovery of platinum-containing particles.

In another embodiment, the use involves recovering copper-containing particles from mineral particles having a Mohs hardness of 3 to 4. In yet another embodiment, the use relates in particular to the recovery of copper-containing particles from low-grade ore.

The embodiments described above can be used in any combination with each other. Several embodiments may be combined to form further embodiments. A flotation cell to which the present disclosure relates may comprise at least one of the embodiments described above. It is obvious to a person skilled in the art that, as technology advances, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not limited to the examples described above; instead they may vary within the scope of the claims.

Claims (39)

1. A flotation cell (1) for treating particles suspended in a slurry and for separating said slurry into underflow (400) and overflow (500), said flotation cell comprising: a flotation cell (10) comprising a center (11), a perimeter (12), a substantially horizontal flat bottom (13), and side walls (14); launder (2) surrounding the perimeter (12) of said flotation cell (10) and launder rim (21); an open froth surface ( _Af ) at the top of said flotation cell (10); and a foam plug (6) shaped to direct the foam (5) in said open foam surface (A _f ) towards said trough lip (21 ), It is characterized in that the flotation cell further includes a spray pipe (4) for introducing the slurry feed (100) into the flotation cell, and the spray pipe includes: an inlet nozzle (41) for feeding a slurry feed (100) into said injection pipe; an inlet (42) for pressurized gas to which said slurry feed is subjected as it is discharged from said inlet nozzle; an elongated chamber (40) arranged to receive said slurry feed under pressure; and an outlet nozzle (43) comprising a throttle valve and configured to restrict the flow of slurry feed from said outlet nozzle and to maintain the slurry feed in said elongate chamber under pressure, said outlet nozzle (43) configured to generate supersonic shock waves in said slurry feed (100), said supersonic shock waves causing formation of flotation bubble-particle agglomerates. 2. The flotation cell according to claim 1, characterized in that the height ( H) Up to 20% lower at the periphery (12) of the flotation cell than at the center (11) of the flotation cell. 3. The flotation cell according to claim 1, characterized in that the foam plug (6) is a conical central foam plug arranged concentrically with the center (11) of the flotation cell (61). 4. A flotation cell according to claim 3, characterized in that the central froth plug (61) is arranged to plug 25% to 40% of the open froth surface ( _Af ). 5. The flotation cell according to claim 3 or 4, characterized in that the included angle (α) of the central foam plug (61) is 20° to 80°. 6. The flotation cell according to claim 1, characterized in that the foam plug (6) is an inner peripheral plug arranged in the side wall (14) of the flotation cell (10) ( 62 ) such that the lowest point ( 620 ) of the inner peripheral plug is at a distance ( h ₂ ) from the bottom ( 13 ) of the flotation cell. 7. The flotation cell according to claim 6, characterized in that, the distance (h ₂ ) is that of the flotation cell (10) as from the bottom (13) to the edge of the flow cell ( 21) The distance is measured from 1/2 to 2/3 of the height (H). 8. A flotation cell according to claim 6 or 7, characterized in that said inner peripheral obstruction (62) comprises a diagonal inlet (14c) from said lowest point (620), said The diagonal inlets are angled towards the center (11) of the flotation cell and between a first portion (14a) of a side wall (14) of the flotation cell (10) and a second portion ( 14b) such that the angle (β) of said diagonal inlet opening (14c) relative to said first portion (14a) of said side wall is 20° to 80°. 9. A flotation cell according to claim 6 or 7, characterized in that the inner peripheral plug (62) is arranged to plug 1/5 to 1/4 of the slurry area (A _p ), at which The slurry area (A _p ) is measured at a distance (h ₁ ) from the outlet nozzle (43) to the bottom (13) of the flotation cell (10). 10. The flotation cell according to claim 6, characterized in that the flotation cell (10) further comprises a central foam plug (61) arranged concentrically with the center (11) of the flotation cell ). 11. A flotation cell according to claim 10, characterized in that the central froth plug (61) is arranged to plug 25% to 40% of the open froth surface ( _Af ). 12. The flotation cell according to claim 10 or 11, characterized in that the included angle (α) of the central foam plug (61) is 20° to 80°. 13. The flotation cell according to claim 1, characterized in that the jet tube further comprises an impactor (44) configured to contact the slurry feed stream from the outlet nozzle (43) and A stream of slurry feed (100) is directed radially outward and upward from the impactor. 14. The flotation cell according to claim 1, characterized in that the height ( The ratio (H/D) of H) to the diameter (D) measured at the height (h ₁ ) of the outlet nozzle ( 43 ) of the flotation cell from the bottom ( 13 ) is 0.5 to 1.5. 15. The flotation cell according to claim 1, characterized in that the volume of the flotation cell (10) is at least 20 ^m3 . 16. The flotation cell according to claim 15, characterized in that the volume of the flotation cell (10) is 20m ³ to 1000m ³ . 17. The flotation cell according to claim 1, characterized in that it comprises 2-40 injection pipes (4). 18. The flotation cell according to claim 17, characterized in that the flotation cell comprises 4-24 jet tubes. 19. The flotation cell according to claim 1, characterized in that the injection pipe (4) is connected to the periphery (12) of the flotation cell (10) at a certain distance from the foam plug (6). Arranged concentrically. 20. The flotation cell according to claim 1, characterized in that the flotation cell further comprises a regulating loop (3). 21. The flotation cell according to claim 20, characterized in that said regulating circuit comprises a pump tank (30) in fluid communication with said flotation cell (10), in which new slurry A slurry feed (200) and a slurry fraction (300) taken from said flotation cell (10) via an outlet (31) are arranged to be combined into a slurry feed (100). 22. The flotation cell according to claim 21, characterized in that the outlet (31) is arranged at the outlet distance (L ₄ ) from the bottom (13) of the flotation cell (10) at the At the side wall (14) of the flotation cell (10). 23. The flotation cell according to claim 22, characterized in that, the outlet distance (L ₄ ) is that of the flotation cell (10) as from the bottom (13) to the edge of the flow cell (21) The distance is measured from 0% to 50% of the height (H). 24. A flotation cell according to any one of claims 21 to 23, characterized in that the regulating circuit (3) further comprises a pump (32), the pump (32) being arranged to flow from the A flotation cell (10) sucks in the slurry portion (300) and forwards a slurry feed (100) from the pump cell (30). 25. A flotation cell according to any one of claims 20 to 23, characterized in that the regulating circuit (3) further comprises a distribution unit arranged to distribute the slurry feed (100). 26. A flotation line (8) comprising a plurality of fluidly connected flotation cells, characterized in that at least one of said flotation cells is according to any one of claims 1 to 25 The flotation cell A(1). 27. A flotation line according to claim 26, characterized in that the flotation cell A (1) is preceded by a flotation cell B (1a). 28. A flotation line according to claim 26 or 27, characterized in that the flotation cell A (1) is preceded by a mechanical flotation cell (1b). 29. The flotation line according to claim 27, characterized in that said flotation line comprises: roughing section (81) with flotation cell B (1a); a scavenging section (82) with flotation cells B (1a) arranged to receive an underflow (400) from said roughing section; and A scavenging cleaning section (820) with flotation cell B (1a) arranged to receive overflow (500) from said scavenging section, wherein said scavenging section and/or scavenging cleaning section The last flotation cell is the flotation cell A (1) according to any one of claims 1-25. 30. A flotation line according to claim 29, characterized in that the flotation cell A (1) is preceded by a mechanical flotation cell (1b). 31. Use of a flotation line (8) according to any one of claims 26 to 30 for recovering particles comprising valuable material suspended in a slurry. 32. Use according to claim 31 for recovering particles comprising non-polar minerals. 33. Use according to claim 32, the non-polar mineral being graphite, sulfur, molybdenite, coal or talc. 34. Use according to claim 31 for recovering particles comprising polar minerals. 35. Use according to claim 34 for recovering particles from minerals having a hardness of 2 to 3 on the Mohs scale. 36. The use according to claim 35, said mineral being galena, sulphide mineral, PGM, and/or REO mineral. 37. Use according to claim 35 for the recovery of particles comprising Pt. 38. Use according to claim 34 for recovering particles comprising Cu from a mineral having a Mohs hardness of 3 to 4. 39. Use according to claim 38 for recovering particles comprising Cu from low grade ore.

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