DE102006024386A1 - Onsite treatment of acidic post-mining surface waters, by manufacturing suspension from treatment agent and lake water, adding the agent to surface water, transferring suspension to feed unit, pressure increasing or diluting the suspension - Google Patents

Abstract

The onsite treatment of acidic post-mining surface waters by addition of treatment agents, such as lime products, caustic soda, sodium carbonate and carbon dioxide, comprises manufacturing a suspension from treatment agents and lake water and/or external water in a fixed or mobile station on land, adding treatment agents up to 35 ma.%, directly transferring the suspension of treatment agents to a floating, self-driven and mobile feed unit, pressure increasing or diluting the suspension of treatment agents, and transferring final suspension of treatment agents into the concerned surface waters. The onsite treatment of acidic post-mining surface waters by addition of treatment agents, such as lime products, caustic soda, sodium carbonate and carbon dioxide in suspended form, comprises manufacturing a suspension from treatment agents and lake water and/or external water in a fixed or mobile station on land, adding treatment agents up to 35 ma.%, directly transferring the suspension of treatment agents by means of a floating pipeline system from a combination of pseudo-stationary and a flexible pipeline system or consisting of a flexible pipeline system to a floating, self-driven and mobile feed unit, pressure increasing or diluting the suspension of treatment agents according to requirements in the pipeline system or at the floating, mobile and portable feed unit, and transferring final suspension of treatment agents into the concerned surface waters using a distribution mechanism. Before the entry into a water body, the concentration of the treatment agent in the transferred suspension is reduced by means of suitable mechanisms in the pipeline conduction system and/or at the floating and mobile feed unit. The feed concentration of the treatment agents is adjusted depending on the quality parameters in the water bodies, such as pH, or as a function of the acid neutralization capacity determined by means of titration. The concentration is adjusted at a higher value at low pH values and low acid neutralization capacities than at higher pH values and higher acid neutralization capacities. The distribution of the treatment agents on the surface of the water bodies during the movement of the floating mobile and portable feed unit takes place at a speed of up to 15 km/h by means of suitable mechanisms. The distribution of treatment agents on the surface of the water bodies takes place area-wise up to 15,000 m2> or linearly with a working width up to 300 meters. The mobile land system is operated at the beginning of the suspension pipeline on the banks of the water body during the period of treatment depending on the pH and/or using acid neutralization capacity that is determined according to titration methods. An independent claim is included for a device for onsite treatment of acidic post-mining surface waters by addition of treatment agents, such as lime products, caustic soda, sodium carbonate, and carbon dioxide.

Description

The invention relates to the raising of the pH and the improvement of the water quality of acidic surface waters, in particular to waters with a water volume of> 500,000 m ³ .

In The result of mining will be cavities in the used landscape created, which gradually fill with ground and surface water. In many cases is caused by the re-emerging groundwater and the associated geological and chemical conditions in the newly created overburden Lake landscape created by extremely acidic waters with high heavy metal contents, especially with high iron contents is marked.

Main entry source for dissolved substances and acids in such Tagebausee are the groundwater and the tilting material. The acid potential The tilting material is usually based on the weathering of the iron disulfides contained by the rearrangement of the coal cover layers in the open pit. The so-called waste material becomes intense the weathering-promoting components Exposed to air (oxygen) and water. The deposited and weathered Tipping material will over time through groundwater and leachate washed out, the so mobilized substances removed and, for example introduced in open-pit mines by groundwater recovery. A second The source of entry is the erosion of banks of tilting material. The Mobilization takes place here by waves, rainwater etc. Result of weathering and leaching is a highly mineralized acid Water containing sulphate as the acid carrier. and iron ions dominate.

Out The prior art is known, such acidic waters before Connection of these waters the receiving water by means of so-called mine water purification systems (GWRA) However, the actually acidic waters remain in this Trap in his acid hostile environment and is in his Usability limited.

Also known are so-called inlake processes z. In DE 103 04 009.9 described, after using the Inlake process technology, injector and mixing technology and fine-grained neutralizing agent and intelligent distribution technology on floating piping an improved effect on the use of neutralizing agents is achieved. A good mixing of the neutralizing agent and the distribution of the suspensions in the lake are limited in the efficiency, the material conversion and thus in the cost optimization of such methods. To achieve high efficiencies large volume flows are to be moved, which causes very high operating costs.

According to a proposal by file number DE 103 44 857.8 is achieved by designing the distribution device, the adjustment of the substance concentration to <1% on the sea surface and the pH adjustment depending on the feedstock in the water body to achieve a high efficiency. In particular, in morphologically unfavorable waters with predominantly shallow water areas and / or deep hoses and heavily articulated waters possibly with island areas, this method has limits.

Also in the publications DE 4124073 A1 and WO 02/16272 A1 describes methods for treating acidic waters. However, the application in larger mining lakes requires a disproportionate technical-economic effort and is not suitable here.

In DE 20 2004 002 159.5 an arrangement is described, which is characterized by a combination of tank / silo vehicle, intermediate storage container, a floating mobile and mobile / mobile storage and entry unit with a distribution system and are transported with the neutralizing agent on an acidic waters and distributed. The disadvantage of this arrangement is that this arrangement can only be used on waters whose bank area is fixed at least in places accordingly. Due to the required transport costs large and costly floating facilities are required. The complex storage and entry unit must have a high load capacity and causes a high energy demand.

After a procedural proposal DE 10 2004 032 404 the substance concentration of each neutralizing agent used should be adjusted to <0.2% down to one meter depth by the speed of a floating mobile and mobile storage / transport and entry unit on the surface of the water. The disadvantage of this solution is that after emptying the storage and transport device, the system must travel empty over the body of water and the effectiveness of the system is additionally reduced by required Umschlagsprozesse. Overall, the operating costs are significant compared to the product cost. The complex system must have a high load capacity and is therefore very expensive to manufacture and causes high operating costs.

The aim and purpose of the invention is to find a possibility based on the intake conditioning of acidic waters, according to which the conditioning agents can be used very effectively, with high reaction efficiency, with little expenditure of time and with low operating costs.

According to the invention Task solved by that a mobile or stationary land plant for the production and promotion a suspension of conditioning agents such as Lime products, caustic soda, soda, CO or combinations thereof with Seawater and / or is operated with extraneous water and in the Land conditioning produced conditioning agent suspension directly over a> 200 m long floating Pipe system and continue over a floating, mobile and mobile entry unit with own drive and with a distribution device for the conditioning agent suspension discharge equipped is introduced into the surface water concerned becomes.

The Floating, mobile and mobile entry unit can be adapted the technology to the local Conditions or the quality parameters such as the pH value or the acid capacity of the water body determined by titration with further accessories such as a generator and / or pontoons and / or conveyors and / or mixing devices.

Usually the floating mobile and mobile entry unit is a ship, Pontoon, catamaran or similar, which is equipped by means of a suitable drive.

The Conditioner in the subsidized suspension is at the implementation of the process with a concentration of up to 35 Ma. % promoted. In dependence of quality parameters in the waters how the pH value or the acid capacity determined by titration becomes the Entry concentration adjusted, taking at low pH and low acid capacities the Concentration higher is set as at higher pH values and higher Acid capacity. So that can chemical-physical driving forces between conditioning agent on the one hand and the acidic surface water on the other hand be used optimally. Furthermore, concentrations, the too undesirable Side reactions, such as calcite precipitation at selectively elevated calcium concentration or at times elevated pH is avoided.

The floating conduit system for conditioning agent suspension conveyance exists in the implementation the method of a flexible conduit or a combination by quasi-stationary management and flexible piping, with or without additional stabilizers, such as pontoons, for the stabilization of the pipe and / or for the reception of plant engineering as well as with or without conveyors for pressure increase or further dilution the conditioning agent suspension is equipped. This way you can if necessary, the conditioner in the subsidized suspension by suitable Facilities in the pipeline and / or at the floating, mobile and movable entry unit in front of the entry into the body of water in be reduced in concentration.

The is floating conduit system in a partial quasi-stationary design dependent on from the total line length starting at the land plant with> 1/3 the total length quasi-stationary executed. Preferably, from a line length of> 300 m, the quasi-stationary design of a Line content. In the execution can the quasi-stationary Lead share a higher diameter have, as the flexible line share or vice versa.

Of the quasi-stationary Line share is preferably additionally by pontoons and / or Anchor secured. The flexible conduit part is preferably through float secured. The attitude of the support line can also be an air filled Parallel line or air filled line sections be used.

The Distribution of the conditioning agent takes place on the surface of the water while the movement of the floating mobile and mobile entry unit at a speed of up to 15 km / h via suitable facilities.

When implementing the method, sprinklers, nozzles or baffle distributors above the water surface and / or underwater nozzles or tow hoses on the floating and mobile entry unit are preferably used to distribute the conditioning agent suspension during movement of the floating mobile and mobile entry unit. The distribution of the conditioning agent on the surface of the water surface or linear with a working width of up to 300 m and / or simultaneously on an area of up to 15,000 m ² .

By the active movement of the entry device becomes intimate mixing of alkaline suspension and acidic seawater, causing the reaction rate for the reactions of the ions in question and thus the degree of utilization of the conditioning agent is increased in this way.

The active distribution of the conditioning agent is carried out in the implementation of the method in the water with the aim of a maximum distribution in Water body and a high degree of utilization of the neutralization potential to effect. With the help of the proposed solution, with the combination of a land-based suspension production directly with a floating entry unit with its own drive, it is possible to achieve high efficiencies compared to known solutions even at higher feed concentrations. As a result, remediation objectives are already achieved with low energy consumption and economic operation. In addition, the land plant can be implemented with the beginning of the suspension line on the shore of the water in the period of treatment depending on the monitoring results, especially the pH and / or determined by titration acid capacity to hitherto untreated sea areas with unfavorable water quality with less Total effort, such as to achieve shorter pipe lengths and lower energy consumption.

With Help of the found solution the neutralization of acid surface waters with high efficiency, in a short time in a simple and economical way possible. Thus became a technical solution found, with the improvement and maintenance of the quality of large quantities of water especially in acid mining lakes is possible and the basics for the Achieving the re-use goals much faster and sustainable can be created.

The Principle of the invention will be apparent from the following application example be explained in more detail.

An acid mines with an area of 5 km ² , a mean diameter of 2.5 km, a mean sea depth of 10 m and a volume of 50 million m ³ , which has a pH of 3.0 and a K _{b7 , 0 value} of 3 mmol / l, is to be treated with a suspension of Weißkalkhydrat and seawater. The demand for hydrated lime for a pH increase to 7 at an efficiency of 100% theoretically 5,500 t.

From a 50 m ³ silo with regulated discharge, 7.5 t / h of white lime hydrate are added to a mixing vessel with agitator. In this mixing container 50 m ^{3 of} seawater are simultaneously supplied by means of a submersible pump, thus producing a 15% suspension. A stand measurement regulates the supply of seawater.

By means of an eccentric screw pump, this suspension is conveyed at a flow rate of 2.2 m / s via a flexible conduit having an inner diameter of 90 mm and a length of 1000 m to the rear region of a working ship. The flexible cable is firmly connected to the working ship. On the work vessel a submersible pump with a capacity of 100 m ³ / h is arranged, is conveyed with the seawater via an injector to a distribution device. Via a second connection on the injector, the dosing of the 15% suspension takes place on the working vessel. On the further flow path to the distribution device is formed by exchange of pulses, the new suspension with a Weißkalkhydratkonzentration of 5.0% for distribution in acidic waters.

In the front area of the work vessel, two equal-cycle semicircular sprinklers are arranged side by side over a supporting structure at a distance of 20 m, which distribute the suspension with a throw of 40 on the water surface over an area of 650 m ² and over a working width of 100 m. During the movement of the working ship at 3 km / h with constant suspension feed from the land plant via the flexible pipe, a total distribution area of 300,000 m ² / h is achieved. Due to this extremely possible dilution, the white-lime hydrate concentration, based on an effective water body depth of 2 m, is 0.0013 Ma. %. Using the found process and fixture solution daily for 8 hours and 5 days per week, a pH of 4.3 is achieved after 18 weeks in the entire lake area. In total, the use of white lime hydrates is 5270 t. For further treatment of the water, the use of white lime hydrates is reduced to 2.5 t / h with the same amount of water. The suspension concentration decreases to 1.66% before entry into the water and accordingly further in the water body to be treated. In the above-mentioned implementation of the method, a pH of 7.0 is set after a further 10 weeks at a Weißkalkhydrateinsatz of 930 t in the entire maritime area.

By the by the found solution possible favorable utilization the chemical-physical driving forces between the Weißkalkhydratsuspension on the one hand and the acidic components of the surface water on the other hand is for the procedure a total of 6,200 t of hydrated lime needed and a high efficiency for the utilization of the alkalinity potential introduced into the body of water of 90% achieved.

In a further variant of the solution found can be arranged in the line course after 500 m on a pontoon, which is anchored and with which the pipeline is stabilized, a mixing and conveying, here a dilution of the suspension to 3.33 Ma.% And a Increasing the amount of suspension effected to 150 m ³ / h. The delivery line from this pontoon to the working ship is designed with an increased nominal diameter of 150 mm. On the work ship, the distribution device is arranged next to the drive. The distribution he follows analogously with the movement of the working ship.

The possesses treated waters according to the proposed method Ausleitungsqualität in public waters with simultaneous stimulation of biological self-regulation in the Waters.

With Help of the proposed procedure will be the use of hostile Acid mining for recreation, management and as a cache made possible in a simple way with economic effort and at the same time the buffer capacity raised significantly.

at the subsequent flooding of the treated water is all biological life and existing biological and chemical alkalization potential, which in the natural Flooding water, is present, largely preserved.

Claims (12)

Process for the in-lake conditioning of acidic surface waters by introducing conditioning agents, such as lime products, caustic soda, soda, CO ₂ or combinations thereof, in suspended form with the following process steps: - Preparation of a suspension of conditioning agent and sea water and / or extraneous water in a stationary or mobile Station on land, - Addition of conditioning agent up to 35 Ma.%, - Promotion of this conditioning agent suspension directly via a floating line system of a combination of quasi-stationary line and flexible line or flexible line only to a floating, self-propelled mobile entry unit, - further pressure increase or further dilution of the conditioning agent suspension as required in the course of the line or on the floating, mobile entry unit, - introduction of the final conditioning agent suspension in the respective Oberflächengewä sser by means of a distribution device. Method according to claim 1, characterized in that that the conditioning agent in the subsidized suspension by suitable Facilities in the pipeline and / or at the floating, mobile and movable entry unit in front of the entry into the body of water in the concentration is reduced. Method according to claims 1 to 2, characterized that the entry concentration of the conditioning agent Depending of quality parameters in the water, as set by the pH value or the acid capacity determined by titration at low pH and low acid capacities Concentration set higher is considered higher pH values and higher acid capacities. Process according to Claims 1 to 3, characterized that the distribution of conditioning agents on the water surface during the movement the floating mobile and mobile entry unit with a Speed up to 15 km / h over appropriate facilities. A method according to claim 1 and 4, characterized in that the distribution of the conditioning agent on the surface of the water surface area up to 15,000 m ² or linear with a working width up to 300 m. Method according to Claims 1 to 5, characterized that the mobile land plant with the beginning of the suspension line on the shore of the water in the period of treatment depending on the monitoring results, especially the pH value and / or the acid capacity determined by means of titration becomes. Apparatus for inlake conditioning of acidic surface waters Entry of conditioning agent in suspended form from the following System parts in construction execution sequence: - local festivals or mobile land plant with mixing device for conditioning agents and Water, - quasi-stationary management and flexible suspension delivery line or exclusively flexible delivery line with possibility the application of additional Stabilization devices and / or other systems engineering or Pressure Boosting Technology, - floating, mobile entry unit with distributor and applications for a drive, diluter or pressure increasing device. Device according to claim 7, characterized in that that in dependence from the total line length starting at the land plant a line piece with> 1/3 of the total length quasi-stationary is executed. Device according to claims 7 and 8, characterized in that that from one line length of> 300 m a proportion of pipelines quasi-stationary is executed. Apparatus according to claim 7 to 9, characterized that the quasi-stationary Lead share a higher one Diameter, as the flexible line share. Apparatus according to claim 7 to 9, characterized in that the quasi-stationary line portion has a smaller diameter than the flexible line share. Apparatus according to claim 7 to 11, characterized that the quasi-stationary Line share is secured by pontoons and / or anchors.