CN111819003A - Apparatus and method for recovering particles from slurry - Google Patents

Abstract

The present invention relates to an apparatus and method for recovering suspended particles from a slurry. The apparatus comprises a main body, at least one operably inclined corrugated plate and a collector. The main body defines a slurry flow area and has an inlet and an outlet at an operable upper area and a lower area of the main body, respectively, and the flow area extends between the inlet and the outlet. The corrugated plate is contained in the main body and comprises at least one corrugation forming a peak extending within the flow area. The collector is associated with at least one peak and is positioned on the inlet side of the corrugated plate, the mouth of the collector being positioned at the edge of the corrugated plate to allow low-density particles in the slurry within the slurry flow area to rise and be guided along the bottom surface of the peak toward the mouth of the collector. In an inverted configuration, the apparatus and the associated method can be used to recover particles having a density greater than that of the slurry from the slurry.

Description

Apparatus and method for recovering particles from slurry

technical field

The present invention relates to an apparatus and method for recovering particles from a slurry. It is especially useful for recovering suspended particles (eg, hollow ceramic microspheres) from slurries containing suspended particles (eg, water-based slurries). However, in an inverted configuration, the apparatus and method can be used to recover particles from the slurry that are greater than the density of the slurry.

Background technique

Hollow ceramic microspheres consisting of alumina and silica filled with air or inert gas are a by-product of burning coal at temperatures between about 1500°C and 1750°C. These hollow ceramic microspheres, called "hollow microbeads," are found in fly ash from thermal power plants. Their chemical composition and physical properties vary depending on the combustion process and the composition of the coal used. Each such ceramic microsphere typically has a diameter of about 5 to 500 microns and a density between 0.4 and 0.8 g/cm3, which is less than the density of water.

Hollow ceramic microspheres were initially considered an undesirable and intractable waste because, once dry, it becomes a persistent airborne dust. Additionally, its low density makes it unsuitable for landfills, where groundwater would wash it to the surface. However, at the time of filing this application, it has become a valuable commodity with a commercial value of approximately $1000 per ton. Depending on its grade, hollow ceramic microspheres have a variety of industrial applications, including use in lightweight insulation products, just to name a few; fillers for paints, varnishes, and plastics; lightweight aggregates in concrete; and as a filler for asphalt rubber. filler. The benefits of using hollow ceramic microspheres as fillers in such applications include weight reduction, lower viscosity, lower shrinkage, and improved fire performance.

The main by-products of coal-fired thermal power plants are slag, bottom ash and fly ash. The heavier slag and bottom ash are removed at the bottom of the power plant boiler, while the lighter fly ash rises and is usually transported with the flue gas from which the fly ash is separated and transported to the ash by dry or wet processes. dam.

Wet transport of fly ash may form a slurry and discharge into a settling tank. Here, most of the ash will settle and the floating hollow ceramic microspheres will rise to the surface. However, the density difference between the hollow ceramic microspheres and the water makes the rate at which the microspheres rise towards the water surface extremely slow. Workers need to manually collect the floating hollow ceramic microspheres by skimming them from the water surface. Therefore, the process can be quite laborious and time-consuming.

Furthermore, about 80% of the hollow ceramic microspheres contained in the fly ash were destroyed during transport to the sedimentation tank, trapped or contaminated with the ash, or rendered unusable. Since the formation of these hollow ceramic microspheres is only about 0.2% to 2% of the fly ash from which they are derived, further losses of such a high percentage are unsustainable.

Accordingly, there is room for improvement in this regard, and the invention disclosed herein addresses these and other deficiencies, at least to some extent. Furthermore, since the device is reversible to separate particles from the slurry with a density greater than that of the slurry, the present invention can achieve a dual purpose.

The preceding discussion of the background of the invention is intended only to facilitate an understanding of the invention. It should be understood that this discussion is not an admission or admission that any of the material cited was part of the common general knowledge in the art as of the priority date of this application.

SUMMARY OF THE INVENTION

According to the present invention, an apparatus is provided, comprising:

a body defining a slurry flow region and having an inlet and an outlet, respectively, in opposing first and second regions of the body, the slurry flow region extending between the inlet and the outlet;

at least one operatively inclined corrugated plate contained within the body, the corrugated plate including at least one corrugation forming a peak or valley extending within the slurry flow region; and

A collector is provided on the inlet side of the corrugated plate, and:

The collector is associated with at least one peak, and the mouth of the collector is positioned at the edge of the corrugated plate to allow particles in the slurry in the slurry flow region that are less dense than the slurry to rise and be removed along the underside of the peak. leading to the mouth of the collector; or

The collector is associated with at least one valley, and the mouth of the collector is positioned at the edge of the corrugated plate to allow particles of greater density than the slurry in the slurry in the slurry flow region to descend and be pierced along the upper side of the valley. Guide to the mouth of the collector.

It is a further feature having the apparatus having a plurality of spaced and operably inclined corrugated plates contained within the body, each corrugated plate including at least one corrugation formed in the slurry flow region extending a peak or a valley; and each corrugated sheet has a plurality of corrugations to form a plurality of peaks and a plurality of valleys.

Another feature is that the valleys of the corrugated sheet are arranged such that the high density particles contained in the slurry are directed downwardly along the operative top side of the valleys.

When the density of the particles to be recovered is lower than the density of the slurry, the opposing first and second regions of the body refer to the operative upper and lower regions of the body, respectively. In a further feature, the corresponding corrugations of adjacent corrugated plates form peak groups; and each peak group has a collector associated therewith disposed on the inlet side of the corrugated plate, the mouth of each collector abutting against the opening of the corrugated plate. edge.

Another feature is that each collector is in fluid communication with a riser operatively extending upwardly from the collector to direct low density particles from the mouth of the collector and out of the body through the riser. Another feature is that the collector is operable to taper upwardly to intersect the riser, thereby assisting low density particles in the slurry to enter and travel along the riser.

Alternatively, when the density of the particles to be recovered is greater than the density of the slurry, the opposing first and second regions of the body are referred to as the operative lower and upper regions, respectively. A further feature is that the corresponding corrugations of adjacent corrugated sheets are formed into valley groups; and for each valley group there is associated therewith a collector disposed on the inlet side of the corrugated sheet, the mouth of each collector abutting on the edge of the corrugated sheet.

Another feature is that each collector is in fluid communication with a sinker tube operatively extending downwardly from the collector to direct high density particles from the mouth of the collector and out of the body through the sinker tube. Another feature is that the collector is operable to taper downwardly to intersect the immersion tube, thereby assisting high density particles in the slurry to enter and travel along the immersion tube.

Another feature is that the body is made to define an intermediate space between its inlet and the corrugated plate, and that the intermediate space contains one or more baffles positioned transverse to the slurry flow area.

A still further feature is that the body has an operable vertical portion and an inclined portion downstream of the operable vertical portion, the inlet is provided in the operable vertical portion, and the one or more corrugated plates are located in the inclined portion; and Make the second region of the main body a funnel-shaped intake outlet.

A further feature is that each corrugated sheet operates at an inclination of between 60° and 80° from the horizontal, preferably 70°; and that the inclined portion of the body has substantially the same inclination as the corrugated sheet.

A further feature is that a slurry is provided comprising a mixture of water, fly ash and hollow ceramic microspheres; the low density particles are hollow ceramic microspheres; the hollow ceramic microspheres are hollow microspheres.

The present invention extends to a method of extracting low density particles from a slurry, the method comprising:

provide a device as described above;

receiving a slurry containing low density particles into the body through an inlet;

flowing the slurry along a slurry flow region;

raising the low density particles and being directed along the underside of at least one peak formed by at least one inclined corrugated plate;

The low density particles are passed into the port of the collector associated with each peak.

The present invention also extends to a method of extracting low density particles from slurry comprising the steps of:

the slurry flows into the body through the inlet and flows through a flow region containing at least one operatively inclined corrugated plate, the corrugated plate including at least one corrugation forming a peak extending along the flow region;

raising low density particles and being directed along the bottom side of at least one peak formed by at least one inclined corrugated plate;

in one or more collectors associated with each peak, collecting low-density particles rising along at least one peak formed by at least one inclined corrugated plate; and

Low density particles from the collector are directed through the riser operatively upwardly above the level of the inlet into the body.

The present invention further expands a method for extracting high-density particles from slurry, the method comprising:

Provide a device as above;

receiving a slurry containing high density particles into the main body through an inlet;

flowing the slurry along a slurry flow region;

sinking high-density particles and being directed along the upper side of at least one valley formed by at least one inclined corrugated plate;

The high density particles are passed into the mouth of the collector associated with each valley.

The present invention further extends to a method for total recovery of high density particles from pulp comprising the steps of:

flowing the slurry into the body through the inlet and through a flow region containing at least one operatively inclined corrugated plate, the corrugated plate including at least one corrugation forming a valley extending along the flow region;

sinking the high-density particles and being directed along the upper side of at least one valley formed by at least one inclined corrugated plate;

in one or more collectors associated with each valley, collecting high-density particles sinking from at least one valley formed by at least one inclined corrugated plate; and

The high-density particles from the collector are directed to flow operatively downward, where they are drawn from the body through the immersion tube, beyond the height of the body inlet.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

Brief Description of Drawings

In the picture:

Figure 1 is a perspective view of an apparatus for separating low density particles from a slurry according to the present invention;

Figure 2 is a cross-section of a corrugated plate contained within the body of the device shown in Figure 1;

Figure 3 is a cross-sectional view of two adjacent corrugated plates;

Figure 4 is a perspective view of a corrugated plate and a collector associated with the peaks of the corrugated plate;

5 is a perspective view of an alternate embodiment of a corrugated plate and collector associated with the peaks of the corrugated plate;

Figure 6 shows a flow chart of a method for separating low density particles from a slurry using the apparatus shown in Figure 1;

7 is a perspective view of an apparatus for separating high-density particles from a slurry according to a second embodiment of the present invention; and

FIG. 8 is a cross-section of two adjacent corrugated sheets of the apparatus shown in FIG. 7 .

Detailed description with reference to the accompanying drawings

An apparatus for separating low density particles from a slurry is provided. It has particular application in the removal of hollow ceramic microspheres from water-based slurries that are part of a process for wet separation of fly ash from coal-fired thermal power plants.

In an exemplary embodiment, the hollow ceramic microspheres may be hollow microspheres.

The device has a body defining an area along which, in use, the slurry can flow. The body has, in its operative upper region, an inlet for receiving the slurry, and an outlet through which the remaining slurry (ie the portion of the slurry remaining after the low density particles have been at least partially extracted therefrom) may pass. The exit leaves the main body.

The body includes at least one operably inclined corrugated plate having at least one peak-forming corrugation. For efficiency reasons, the body may typically contain a plurality of corrugated sheets, each corrugated sheet having a plurality of corrugations, thereby forming a plurality of peaks and valleys. Adjacent corrugated sheets are spaced apart to form a flow region between them through which the slurry can flow. The direction of the sloped peaks and valleys of the corrugated sheet generally extends in the flow path.

The apparatus further includes one or more collectors, each associated with a peak and disposed on the inlet side of the corrugated plate. The mouth of each collector is positioned at the edge of the corrugated sheet. When multiple corrugated sheets are used, corresponding corrugations on adjacent corrugated sheets may form peak groups. Thus, a collector can be associated with each peak, so that a group associated with the port of the associated collector can be provided, wherein the group of peaks terminates on the inlet side of the corrugated plate.

In use, a slurry containing low density particles, such as a slurry containing hollow ceramic microspheres, may enter the body through the inlet and may flow to the outlet. The low density particles can rise and be directed along the bottom of each peak to the mouth of each collector. Therefore, particles traveling along the base of a particular set of peaks may enter a common collector.

Since the operation of the apparatus is dependent on gravity and the relative densities of the slurry components, it should be understood that references to "vertical" or "horizontal" throughout the specification refer to the orientation of the apparatus in use. Similarly, relative orientations such as "below" and "above" refer to the device in an upright orientation.

Figure 1 shows an exemplary embodiment of a device (1) for separating low density particles from a slurry. For illustrative purposes, the device (1) and its operation will be described with an example wherein the low density particles are hollow ceramic microspheres contained in a fly ash slurry. However, it will be apparent to those skilled in the art that the apparatus can be used to separate any particle or to screen particles having a lower density than the rest of the components contained in the slurry.

The device (1) has a body (3) with a vertical part (5) and an inclined part (7) below the vertical part. Both the vertical portion (5) and the inclined portion (7) have a substantially rectangular cross-section. In the vertical part (5) and near the top of the device (1) there is provided an inlet (9) through which the slurry can be received into the body (3). In the lower region of the inclined portion (7), the body defines a funnel (11), the outlet (13) of the body being provided at the narrow end of the funnel (11). In use, the slurry may flow through the body (3) from the inlet towards the outlet within a flow area (12) of the body defined between the inlet and the outlet.

In this embodiment, the inclined portion (7) is at an angle of approximately 70° to the horizontal. Within the inclined portion (7), a plurality of spaced apart and substantially parallel corrugated sheets (15) are contained, the corrugated sheets (15) also being substantially angled at 70° to the horizontal. Each corrugated sheet (15) has a plurality of corrugations and thus defines a plurality of peaks (17) and valleys (19) formed by the corrugations.

As shown more clearly in the transverse sectional view of Figure 2, the corresponding peaks (17) of adjacent corrugated sheets together form a parallel set of peaks (21). Turning now to Figure 4, at the inlet side edge (23) of the corrugated plate (15) there are collectors (25) at each peak group (21) so that each collector is associated with the corresponding peak group ( Peak (17) in 21) is associated. The port (27) of each collector is located against the edge (23) of the plate and is arranged to collect the microspheres flowing upwards from the peak set (21), as will be described in more detail below.

Each collector (25) is in fluid communication with a riser (29) extending upwardly from the collector for directing the microspheres from the port (27) of the collector (25) and through the The riser (29) exits the main body (3).

In the intermediate space (31) generally located between the inlet (9) and the corrugated plate (15), vertically spaced baffles (33) are provided so that the baffles are positioned transverse to the flow direction.

Figure 6 shows a flow diagram of a method (500) for separating low density particles from a slurry using the apparatus (1). As a first step, the fly ash slurry is fed (501) to the body (3) through the inlet (9). The slurry can be gravity fed, pumped into the body or a combination of the two. The slurry will enter the intermediate space (31) in the vertical section (5) and flow downwards through the baffle (33). Said baffles (33) help to reduce the turbulence of the slurry flow, as the result may be more efficient when the downward flow through the device is uniform or as close to uniform as possible.

As a second step, the slurry is flowed (502) along the slurry flow area and through the spaces between adjacent corrugated plates (15). The flow parameters of the slurry through these spaces between adjacent plates, especially its flow rate, are configured to allow separation of the hollow ceramic microspheres from the heavier remainder of the slurry, as further described with reference to FIG. 6 .

Figure 3 shows a longitudinal section of two adjacent corrugated sheets (15). The upper plate shown is sectioned at a peak (17), while the lower plate shown is sectioned at a valley (19). Figure 3 shows a state in which the space (50) between adjacent plates is completely filled with slurry, which in this exemplary embodiment is water-based. The slurry is a mixture of low density hollow ceramic microspheres (51) and high density ash particles (53) and other heavier impurities. It will be appreciated that the remainder of the space (50) between adjacent panels is filled with water.

The fact that the density of the hollow ceramic microspheres (51) is lower than that of the water will cause the microspheres to rise (503) in the water, provided that the flow rate must be slow enough to prevent the microspheres from being carried along. As the hollow ceramic microspheres (51) move upwards in the spaces (50) between adjacent plates (15), the microspheres will eventually meet the bottom surface of the upper plate. The hollow ceramic microspheres (51) will be directed along the upwardly sloping edges of the corrugations towards the peaks (17) of the upper plate. Once the microspheres (51) reach the peaks (17) of the upper plate, the microspheres will be directed upwards along the peaks of the bottom surface of the upper plate.

Instead, the ash particles (53) and other denser impurities move downwards in the spaces (50) between adjacent plates (15) due to their denser density than water. As the ash particles (53) move down, they will eventually meet the upper surface of the lower plate. The ash particles (53) will be directed towards the valleys (19) of the lower plate along the downwardly sloping edges of the corrugations. Once the ash particles ( 53 ) reach the valleys ( 19 ) of the lower plate, they will be directed towards the funnel ( 11 ) and the outlet ( 13 ) along the valleys of the upper surface of the lower plate.

When the microspheres ( 51 ) moving up the peaks reach the inlet side edge ( 23 ) of the corrugated plate ( 15 ), they will enter the mouth of the collector ( 25 ) associated with the associated peak group ( 21 ) (27). The microspheres ( 51 ) will continue to rise within the riser ( 29 ) and eventually leave the body ( 3 ), where they will be transported further. The remaining slurry, including high density ash (53) and other impurities, can be discharged from outlet (13) and transported for further processing.

Figure 4 shows the arrangement of parallel plates. The fact that the sheet is corrugated plays a very important role in the collection of microspheres. As the microspheres float up along the bottom surface of the sheet, they move towards the peaks of the higher sheet, where they concentrate and travel along these peak ridges to the top of the sheet. There they float into the inverted collection channel. These inverted channels cover all points of the peak where the microspheres leave the sheet. From there they float up through the riser and are collected at the top.

Figure 5 shows the parallel plate arrangement of Figure 4 with an alternative tapered embodiment of the collector (25) to better assist the microspheres (51) to enter and move up the riser (29). Although the conical collectors (25) are illustrated as operably tapering upwards from each end to intersect the midspan of the corresponding riser (29) of the collector (25), it should be understood that The riser (29) can be positioned anywhere along the length of the collector (25), as long as the collector (25) is appropriately tapered upwards to intersect the riser.

Similarly, the ash will slide down the sheet and move to the valleys of the sheet and drain to the outlet through the drainage chute.

The apparatus (1) and method (500) described above can solve two problems associated with the separation of hollow ceramic microspheres by flotation according to the prior art. The first problem to be solved is that the microspheres float up very slowly. They typically rise in water at a rate of 100mm per minute, depending on the density and size of the specific microspheres. By passing the slurry between closely spaced parallel sheets, typically about 10 mm apart, the microspheres only need to rise up about 15 mm to reach the bottom surface of the sheet directly above them. Its upward travel path is then defined by the peaks in the corrugations, and upon reaching the upper edge of the plate, will enter the mouth of the collector and travel further upwards in the riser.

In contrast, using conventional flotation methods, a very large flotation cell would be required to allow sufficient residence time for the hollow ceramic microspheres to escape to the surface of the mortar. For example, in a conventional 5m deep flotation cell, the microspheres will typically take 30min to reach the surface.

The second problem addressed is that the device and the method using it can improve the purity of the extracted microspheres compared to the purity extracted by conventional methods. This increase in purity may be due to the fact that once the microspheres reach the inverted collector tube or peak, they may no longer be in contact with the ash particles and only the microspheres will float up the riser (with as little impurities as possible) ). The extraction of microspheres from the riser will be above the water surface, away from the mortar below.

Throughout this specification, unless stated otherwise, the word "comprising" or variations such as "comprising" or "comprising" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers .

The device can further be fabricated in a modular configuration to provide a customized device for varying the slurry flow rate and/or hollow particle recovery. Said modular structure will consist of a standard device that accepts removable corrugated sheets inside, so that the number of corrugated sheets can be varied as required. Alternatively, the modular structure will consist of a standard unit with a fixed number of corrugated sheets, while the number of standard units making up the apparatus can be varied as desired.

Although the present invention has been described above with reference to preferred embodiments, it should be understood that many modifications or variations can be made in the present invention without departing from the spirit or scope of the invention. For example, and where the same reference numerals refer to the same components, the device (10) may be used in an inverted configuration as shown in Figure 7 to be operatively used as a clarifier or the like.

Figure 7 shows an exemplary embodiment of a device (10) for separating high density particles from a slurry. The device (10) has a body (30) with a vertical portion (50) and an inclined portion (70) above the vertical portion. Both the vertical portion (50) and the inclined portion (70) have a substantially rectangular cross-section. An inlet (90) is provided at the vertical part (50) so that the inlet (90) is near the bottom of the device (10) through which the slurry can be received into the body (30).

In the upper region of the inclined portion (70), the body defines a funnel (110), and the outlet (130) of the body is provided at the narrow end of the funnel (110). In use, the slurry may flow through the body (30) from the inlet (90) towards the outlet (130) within a flow region (120) of the body defined between the inlet and the outlet.

The inclined portion (70) is at an angle of about 70° to the horizontal. Within the inclined portion (70), a plurality of spaced and substantially parallel corrugated sheets (150) are contained, which are also all at an angle of approximately 70° to the horizontal. Each corrugated sheet (150) has a plurality of corrugations and thus defines a plurality of peaks (170) and valleys (190) formed by the corrugations.

Corresponding valleys (190) of adjacent corrugated sheets together form parallel valley groups at which collectors (210) are provided for collecting, in use, the downward outflow of particles having a greater density than pulp.

Each collector (210) is in fluid communication with a sinker tube (290) extending downwardly from the collector for directing heavier particles from the mouth of the collector (210) and through the sinker (290). 290) Discharge body (30).

Figure 8 shows a longitudinal section of two adjacent corrugated sheets (150). The upper corrugated sheet shown is sectioned at peaks (170), while the lower corrugated sheet shown is sectioned at valleys (190). Figure 8 shows a state in which the spaces (500) between adjacent plates are completely filled with slurry, which in this exemplary embodiment is a water-based slurry containing high density particles (530).

If the flow rate is slow enough, the fact that the high density particles (530) are denser than water will cause them to sink into the water. As the high density particles (530) move down in the spaces (500) between adjacent plates (150), they will eventually encounter the upper side of the lower plate and eventually be directed down along the upwardly sloping edges of the corrugations Valley of the Plate (190). Once the high density particles ( 530 ) reach the valley of the lower plate, the high density particles ( 530 ) will be directed down the valley, into a collector, and finally out of the device through a sinker tube.

Claims (21)

1. An apparatus, comprising:

a body defining a slurry flow region and having an inlet and an outlet at respective first and second opposed portions of the body, the slurry flow region extending between the inlet and the outlet;

at least one operatively inclined corrugated plate contained within the body, said corrugated plate comprising at least one corrugation that extends to form one peak or one valley within the slurry flow region;

a collector disposed at an inlet side of the corrugated plate, and:

in association with at least one peak, the mouth of the collector is positioned at an edge of the corrugated sheet to allow particles in the slurry flow region having a lower density than the slurry to rise and be directed along the floor of the peak toward the mouth of the collector; or

Associated with at least one valley, the mouth of the collector being positioned at an edge of the corrugated sheet to allow particles of greater density than the slurry in the slurry flow region to settle and be directed along the upper face of the valley toward the mouth of the collector; and

a tube extending from the collector and beyond the inlet of the body.

2. The apparatus of claim 1, comprising a plurality of spaced apart and operatively inclined corrugated plates contained within the body, each corrugated plate comprising at least one corrugation forming a peak and/or a valley extending within the slurry flow region.

3. The apparatus of claim 2, wherein each corrugated plate comprises a plurality of corrugations forming a plurality of peaks and a plurality of valleys.

4. The apparatus according to claim 3, wherein the valleys of the corrugated sheet are arranged such that high density particles contained within the slurry are directed downwards along the top side of the valleys.

5. The apparatus of claim 4, wherein: (1) the opposing first and second regions of the body refer to the operatively upper and lower regions of the body, respectively; (2) the respective corrugations of adjacent corrugated sheets forming groups of peaks, each group of peaks comprising one collector associated therewith, and the collectors being arranged on the inlet side of the corrugated sheets, the mouths of each collector resting against the edges of the corrugated sheets; (3) each collector is in fluid communication with a respective conduit; and (4) the tube is a standpipe operably extending upwardly from the collector for directing the low density particles from the mouth of the collector and out of the body through the standpipe.

6. The apparatus of claim 5, wherein the standpipe operably extends upwardly from the collector, through the intermediate space and beyond the height of the inlet of the body.

7. The apparatus of claim 6, wherein the collectors are operable to taper upwardly to intersect with respective risers.

8. The apparatus of claim 4, wherein: (1) the opposing first and second regions of the body refer to the operatively lower and upper regions of the body, respectively; (2) the respective corrugations of adjacent corrugated sheets forming groups of valleys, each group of valleys comprising one collector associated therewith, the collector being arranged at the inlet side of the corrugated sheet, the mouth of each collector abutting against an edge of the sheet; (3) each collector is in fluid communication with a respective tube; and (4) the tube is a dip tube operatively extending downwardly from the collector for directing the high density particles from the mouth of the collector and out of the body through the dip tube.

9. The apparatus according to claim 8 wherein the dip tube operably extends downwardly from the collector, through the intermediate space and beyond the level of the inlet of the body.

10. The apparatus of claim 9, wherein the collectors are operably tapered downwardly to intersect with respective sinkers.

11. The apparatus of claim 7 or 10, wherein the body defines an intermediate space between the inlet and the corrugated plate, and the intermediate space comprises one or more baffles positioned transverse to the slurry flow region.

12. The apparatus of claim 11 wherein the body includes an operatively vertical portion and an angled portion downstream of the operatively vertical portion, the inlet is disposed in the operatively vertical portion, and the one or more corrugated plates are disposed in the angled portion.

13. The device of claim 12, wherein the second region of the body funnels into the outlet.

14. The apparatus of claim 13, wherein the operative inclination of each corrugated plate is between 60 ° and 80 ° from horizontal.

15. The apparatus of claim 14 wherein the operative inclination of each corrugated plate is 70 °.

16. The device according to claim 14 or 15, wherein the inclined portion of the body has the same inclination as the corrugated plate.

17. The apparatus of claim 16, wherein the slurry comprises a mixture of water, fly ash, and hollow ceramic microspheres, the low-density particles being hollow ceramic microspheres, the hollow ceramic microspheres being cenospheres.

18. A method of extracting low density particles from a slurry comprising the steps of:

(A) providing a device according to any preceding claim;

(B) receiving a slurry containing low density particles into a body through an inlet;

(C) flowing the slurry along a slurry flow region;

(D) causing the low density particles to rise and be directed along the bottom surface of at least one peak formed by at least one inclined corrugated sheet;

(E) passing the low density particles into the mouth of a collector associated with a peak.

19. A method of extracting low density particles from a slurry comprising the steps of:

(A) flowing the slurry into a body through an inlet and through a flow region comprising at least one operatively inclined corrugated sheet comprising at least one corrugation forming a peak extending along the flow region;

(B) causing the low density particles to rise and be directed along the bottom surface of at least one peak formed by at least one inclined corrugated sheet;

(C) collecting low density particles rising from at least one peak formed by at least one inclined corrugated sheet in one or more collectors associated with each peak;

(D) the low density particles from the collector are operably directed upwardly through the riser to a height above the inlet into the body.

20. A method of separating high density particles from a slurry comprising the steps of:

(A) providing a device according to any one of claims 1 to 17;

(B) receiving a slurry containing high density particles into a body through an inlet;

(C) flowing the slurry along a slurry flow region;

(D) sinking said high density particles and being directed along an upper side of at least one valley formed by at least one inclined corrugated sheet;

(E) the high density particles are caused to enter the mouth of the collector associated with each valley.

21. A method of extracting high density particles from a slurry comprising the steps of:

(A) flowing a slurry into a body through an inlet and through a flow region comprising at least one operatively inclined corrugated sheet comprising at least one corrugation forming a valley extending along the flow region;

(B) sinking said high density particles and being directed along an upper side of at least one valley formed by at least one inclined corrugated sheet;

(C) collecting high density particles sinking from at least one valley formed by at least one inclined corrugated plate in one or more collectors associated with each valley;

(D) the high density particles from the collector are operably directed downwardly through the dip tube to a height above the inlet of the body.

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