88 results about "Acid mine drainage" patented technology

A method of repairing mine ecological environment comprises the treatment of mine environment contamination, wherein the tailings, the barren rock, the smelting slag, the waste water from ore cleaning, the waste water from smelting, the acid mine drainage and the ore yard leachwater which are generated from mine development are collected into the tailings storage, at the same time, sludge and organic matter capable of being degradated by microbiology are added therein, and then the tailings storage is given an anaerobic environment artificially, so that, under the action of microbiology and sulfate reducing bacteria, sulfur ion is generated and the pH value of the tailings storage is increased, a plurality of heavy metal ions are cured and settled by sulfur ion to avoid migration, a biomembrane layer-sulfate reducing bacteria reducing-induction biomineralization precipitation composite geochemical barrier is generated in the tailings storage. The repairing of mine ecological environment is realized by the treatment of mine environment contamination. The present invention can be used for tailings storage pollution prevention in tour, and can be used for closing the repairing of mine ecological environment, or can be used for designing new tailings storage by using the technology of the present invention.

Methods and apparatus are disclosed for remediating metal contaminants using hydrocarbons which stimulate the growth of hydrocarbon-utilizing bacteria. The metal contaminants may include heavy metals such as arsenic, antimony, beryllium, cadmium, chromium, copper, lead, mercury, iron, manganese, magnesium, radium, nickel, selenium, silver, thallium and zinc. The hydrocarbon may include alkanes, alkenes, alkynes, poly(alkene)s, poly(alkyne)s, aromatic hydrocarbons, aromatic hydrocarbon polymers and aliphatic hydrocarbons. Butane is a particularly suitable hydrocarbon which stimulates the growth of butane-utilizing bacteria. Remediation may occur in-situ or ex-situ, and may occur under aerobic, anaerobic or dual aerobic / anaerobic conditions. Examples of applications include the remediation of heavy metals, the remediation of arsenic impacted surface water, groundwater and / or soil, the remediation of acid mine drainage, and the treatment of spent metal plating solutions.

Acid mine demineralization methods wherein the acid mine drainage is neutralized, clarified, and forwarded to a microfiltration unit. The so filtered drainage water is then forwarded to a reverse osmosis unit. The permeate from the reverse osmosis unit is characterized by reduced sulfate, silica, calcium, aluminum, iron, magnesium, and manganese levels. Additionally, improvement in reduction of total dissolved solids is noted.

A process for treating acid mine drainage containing heavy and base metals and soluble contaminants is provided. In one embodiment, at least a metal cation is added to the acid mine drainage at a pre-select pH to form insoluble heavy and base metal complexes. After the removal of the heavy and base metal complexes, the pH is raised to the alkaline range. Following removal of base metal hydroxides and gypsum, membrane filtration is employed to generate a treated membrane permeate having a reduced concentration of heavy and base metals and soluble contaminants, and a membrane reject stream containing a concentrated brine. The concentrated brine is further treated with additional lime and at least an aluminum salt to remove remaining soluble contaminants, thus producing a treated water stream with reduced levels of contaminants. Carbonation with CO2 is employed at the end of the process to neutralize flows and further precipitate residual aluminum and calcium salts.

A method for removing metal contaminants from acidic mine wastewater using lignin derivatives, such as lignosulfonates and kraft lignin, an alkali coagulant, such as a lime compound, and an alkaline composition for increasing the pH. The lignin derivatives are dispersed in the wastewater and the coagulant is added, increasing the pH to about 4.5-8.5 and causing the formation of a floc. The alkaline composition is then added to bring the pH to about 9 to 10, causing the further formation of a floc. Optionally, air oxidation is carried out, reducing the pH to about 8.1-8.6. Optionally, a ferric or ferrous salt may also be added. The flocs comprise metal-lignin colloids, metal hydroxides and metal salts. The flocs coagulate to form a sludge. Optionally, fly ash or diatomaceous earth may be added to increase the density and stability of the sludge. The sludge that is formed contains the metals and is separated from the treated water by filtration.

Methods and apparatus are disclosed for remediating metal contaminants using hydrocarbons which stimulate the growth of hydrocarbon-utilizing bacteria. The metal contaminants may include heavy metals such as arsenic, antimony, beryllium, cadmium, chromium, copper, lead, mercury, iron, manganese, magnesium, radium, nickel, selenium, silver, thallium and zinc. The hydrocarbon may include alkanes, alkenes, Aalkynes, poly(alkene)s, poly(alkyne)s, aromatic hydrocarbons, aromatic hydrocarbon polymers and aliphatic hydrocarbons. Butane is a particularly suitable hydrocarbon which stimulates the growth of butane-utilizing bacteria. Remediation may occur in-situ or ex-situ, and may occur under aerobic, anaerobic or dual aerobic / anaerobic conditions. Examples of applications include the remediation of heavy metals, the remediation of arsenic impacted surface water, groundwater and / or soil, the remediation of acid mine drainage, and the treatment of spent metal plating solutions.

A method for removing metal contaminants from acidic mine wastewater using lignin derivatives, such as lignosulfonates and kraft lignin, an alkali coagulant, such as a lime compound, and an alkaline composition for increasing the pH. The lignin derivatives are dispersed in the wastewater and the coagulant is added, increasing the pH to about 4.5–8.5 and causing the formation of a floc. The alkaline composition is then added to bring the pH to about 9 to 10, causing the further formation of a floc. Optionally, air oxidation is carried out, reducing the pH to about 8.1–8.6. Optionally, a ferric or ferrous salt may also be added. The flocs comprise metal-lignin colloids, metal hydroxides and metal salts. The flocs coagulate to form a sludge. Optionally, fly ash or diatomaceous earth may be added to increase the density and stability of the sludge. The sludge that is formed contains the metals and is separated from the treated water by filtration.

The main purpose of the present invention is to provide solid-chemical compositions and methods and means for their use which specifically: (1) provide for a sustained release of active oxygen and complex inorganic phosphates; and (2) create, enhance, and maintain oxidizing and aerobic conditions which favor non-exothermic, chemical-oxidation processes and aerobic bioremediation and fungal bioremediation processes. The present invention discloses advanced solid-chemical compositions and methods for the non-exothermic chemical oxidation and aerobic and fungal biodegradation of organic compounds and certain inorganic contaminants which may be present in solid and liquid wastes, sludges, leachates, acid-mine drainages, waste waters, soils, sediments, ground waters, surface waters, and other environmental media. The preferred embodiments of the disclosed solid-chemical compositions are prepared and used in the forms of granules, briquettes, tablets, capsules, pellets, and the like, which among other advantages, are easier to handle and apply under typical field conditions. These preferred forms of the disclosed chemical compositions can be made to disintegrate subsequent to their application and / or upon contact with water in a significant and predictable manner via relatively minor variations in their formulation and manufacture. This improved functionality enables the time-dependent release profile(s) of the active-oxygen sources and other ingredients to be varied so as to optimize the remediation of contaminants based on site-specific factors or factors pertaining to the specific waste-stream, media and / or the contaminants therein. Organic contaminants which can be treated using this invention include many different types of petroleum products, and more recalcitrant contaminants such as PCBs, PAHs and pesticides can be degraded by using the disclosed compositions and methods to stimulate fungal biodegradation processes. This invention can also be used to treat inorganic contaminants such as the acids and metals present in acid-mine drainage (AMD).

The invention belongs to the field of wastewater treatment and specially, relates to a system for treatment of acid mine drainage and resource recovery of iron, aluminum, copper and zinc in drainage. The system is characterized in that the system is composed of an iron removal system, an aluminum removal system, a copper removal system, a zinc removal system, a sedimentation basin 1 and a sedimentation basin 2 by sequential connection. Based on differences of precipitation performances of a metal ion under pH conditions and differences of solubility products (Ksp) of a reaction between copperand a sulfur-containing organic chelating agent and a reaction between zinc and the sulfur-containing organic chelating agent, through a fractional precipitation method, iron, aluminum, copper, zinc and the like are separated effectively; resource recovery and utilization is realized; hidden troubles of secondary pollution caused by waste residues are eliminated; and treated drainage reaches a reuse standard and can is fed directly into mineral processing pool for reuse. The system has the advantages of simple process, good effect of drainage treatment, stable operation, low costs of treatment, capital construction investment, energy consumption and operation, and wide application prospect.

An apparatus for treating water contaminated with metal sulfates and sulfuric acid such as acid mine drainage (AMD) which in part recycles high pH effluent from later steps in the process back to the earlier steps of the process. The recycled high pH effluent added with magnesium hydroxide to the entering AMD generates precipitates separable from the stream to leave sulfate ladened water. A tangential filtering process is used to separate the sulfate ladened water into one stream of pure water and a second stream containing sulfate. One portion of the second stream is treated with ammonia to yield a cake of ammonia sulfate and aqueous ammonia. Ca(OH)2 is added to another portion of the second stream to produce calcium sulfate cake and the high pH effluent that is recycled back to the first step in the cycle.

Acid mine drainage and surface waters containing sulfate are processed by an electrocoagulator to make aluminum or other polyvalent metal sulfate, which acts as a coagulant for solids suspended in the waters. The process thus removes and puts to good use highly undesirable sulfate anions, obviating combinations with barium and other scale forming metals when the fluids are used in well drilling for other purposes associated with hydrocarbon recovery. Well fluids may be treated with the acid mine drainage including the sulfate coagulant made in it. Efficiency of the process may be enhanced by the addition of an oxidizing agent and / or by passing the fluid through a cavitation device or other mechanism to improve mixing, enabling the process to handle large quantities of acid mine drainage and fluids handled in hydrocarbon recovery, particularly from shale formations.

Electrochemical power generation systems in which the oxidizable reactant is non-carbon constituents of a fossil fuel are provided. The fossil fuel may be coal, which is contacted with an aqueous electrolyte medium used in the systems. The electrolyte may, in certain aspects, be acid mine drainage. Aspects of the invention include systems and methods for remediation of acid mine drainage, where the systems are configured to raise the pH of acid mine drainage. Aspects of the invention also include regenerating the electrolyte using an external electricity source and recirculating the electrolyte to the system.

The invention discloses a method for leaching valuable metals in a waste circuit board by acidophilic bacteria mixed culture, comprising steps of: (1) preparing metal concentrate powders from the waste circuit board; (2) preparing the acidophilic bacteria mixed culture: collecting acid mine drainage from a sulfide ore mine, inoculating the pit water to 9K culture medium according to the inoculation amount of 5-40% by volume, culturing the culture medium in shaking conditions until a large number of reddish-brown precipitates are produced, filtering the solution and obtaining the acidophilic bacteria mixed culture; (3) leaching metals in the metal concentrate powders by the acidophilic bacteria mixed culture. The method of the invention has the advantages of high target metal recovery, low energy consumption, improves the leaching yield of copper by 98% or more during 2 days and the leaching yield of zinc and aluminum by 90% or more during 4 days, simplifies the treatment process and reduces the cost without separating and purifying microbial strains, can recycle the leach liquor repeatedly and substantially realizes zero-pollution emission.

Some waters have high sulfate contents, such as acid mine drainage (AMD), which makes them unsuitable for use in fracturing fluids and difficult to dispose. Such waters may be treated with a solution of barium chloride to react with the sulfate ion of the sulfates and precipitate the sulfates as barium sulfate. Not all of the sulfates needs to be removed for the reclaimed water to be useful in formulating a fracturing fluid. The by-product of the reaction is almost pure barium sulfate, which is an inert, commercially valuable material that may be used in drilling fluids, paint and other industries.

The invention discloses an acid mine drainage / refuse incineration fly ash coupled stabilization treatment method which comprises the following steps: (1) under the conditions of normal temperature and pressure, taking acid mine drainage, adding refuse incineration fly ash in the stirring process to regulate the pH value to 3-5, standing, and carrying out precipitation separation to obtain a clear solution and sludge; (2) adding refuse incineration fly ash into the clear solution obtained in the step (1) to regulate the pH value to neutrality, standing, and carrying out precipitation separation to obtain a clear solution and sludge; (3) adding refuse incineration fly ash into the clear solution obtained in the step (2) to regulate the pH value of the clear solution to 10-12, standing, carrying out precipitation separation to obtain a clear solution and sludge, regulating the clear solution to neutrality, and discharging; and (4) mixing the sludge obtained in the steps (1)-(3), adding a heavy metal stabilizer, uniformly mixing and standing. The weak alkalinity of the refuse incineration fly ash is utilized to perform neutralization pretreatment on the acid mine drainage. The pH value is regulated to near neutrality, and advanced treatment is performed to implement stabilization treatment on the acid drainage and fly ash.

Methods for preventing dissolution of solid substrates, such as metal leaching from coal or corrosion of metal surfaces, are provided. The method comprises coating the solid substrate with a chelate ligand having the general structure: where n is an integer from 1-4, and X is selected from the group consisting of hydrogen, lithium, sodium, potassium, rubidium, cesium, and francium. A method for preventing metal leaching from coal, such as acid mine drainage or metal leachate in runoff from coal refuse piles, is also provided.

A process for treating earth materials such as rock heaps to prevent acid rock drainage therefrom is disclosed. First, the oxygen concentration in the gas-phase of the rock heap is decreased, that is, displaced and / or depleted. This first step may be accomplished physically, chemically or biologically. Then, the gas-phase oxygen concentration in the heap is maintained at a low level. This second step may be provided for in a self-sustaining manner, like, for example, by covering the rock heap with soil and vegetation so that acid rock drainage is prevented indefinitely. Alternatively, the density of the gas-phase of the rock heap may be increased, and maintained at an elevated level indefinitely. The process is applicable to waste heaps from mining and industrial operations such as power generation and minerals processing, and to rubble collections in open and closed mines.

Provided is an agglomeration for neutralizing acid mine drainage which includes a neutralizer and binder component consisting of steel slag in an amount of 75% to 95% by weight of the agglomeration, a sodium carbonate selected from the group consisting of soda ash and pulp liquor in an amount of 0.5% to 25% of the agglomeration, and, optionally, a lime component selected from the group consisting of limestone sand and slag. Further included is a dissolution control and filtration component consisting of an organic material in an amount of 0.24% to 15% by weight of the agglomeration selected from the group consisting of recycled newsprint, sphagnum peat moss, and sawdust. Next is a dispersant and neutralizer component consisting of a surfactant in an amount of 0.01% to 0.075% by weight of the agglomeration. The agglomeration may further comprise an oxidation component such as calcium peroxide, potassium permanganate, and hydrogen peroxide.

The invention discloses a method for processing acid mine drainage. The acid mine drainage is filtered by wood charcoal, calcium carbonate and fiber, and the thickness of each filter layer of the wood charcoal, the calcium carbonate and the fiber is not less than 10mm. According to the method, the pH of the acid mine drainage is adjusted to be 6-8 so as to achieve the national standard of acid mine drainage pH discharge, and stibium content in antimony mine wastewater is reduced to be below 0.5mg / L set by the environmental pollutant discharge standard of Guizhou province, and meanwhile, the method has excellent effect on the treatment on heavy metal mine wastewater.

The invention discloses a method for synchronously recycling heavy metal in garbage leachate and acid mine drainage waste. The method is characterized by comprising the following steps: mixing the garbage leachate and the acid mine drainage waste according to a certain proportion, adding the mixture into a stably running anaerobic reactor, reducing sulfate in the waste water to generate S<2-> by utilizing sulfate reducing bacteria predominant in anaerobic microorganisms, further bonding S<2-> and heavy metal ions to form heavy metal sulfate, and further recycling heavy metal in generated solids containing the heavy metal sulfate by virtue of aerobic and anaerobic calcination methods. According to the method, difficult-to-biodegrade wastewater garbage leachate and acid mine drainage waste are treated, and in addition, the heavy metal in the wastewater garbage leachate and the acid mine drainage waste is effectively recycled, so that the method is economical and environment-friendly, and resourceful transformation in a waste treatment process is realized.

A stream of acid mine discharge is treated by mixing an alkaline aqueous solution of sodium borohydride to form a precipitate which is separated from the stream.

Provided is a banking structure using a rock producing acid drainage. The banking structure includes a banking layer including the rock having acid drainage production possibility and an inhibitor for reducing acid drainage production potential of the rock, a capillary breaker layer stacked between a lower portion of the banking layer and an underground water level surface to prevent underground water from being introduced into the banking layer by a capillary phenomenon, and a finishing layer stacked on an upper portion of the banking layer according to a use thereof.

The invention discloses a method for carrying out purification treatment on acidic mine drainage water of a tailing reservoir. According to the method, the acidic mine drainage water generated in a surface layer and a shallow layer of the tailing reservoir is neutralized by utilizing percolating water in a deep layer of the tailing reservoir, so that the pH (Potential of Hydrogen) value of the earth surface acidic mine drainage water of the tailing reservoir is improved and a lot of iron compound sediment is generated and is used for adsorbing other ions in mining area wastewater to realize co-precipitation and the effect of purifying a water body is realized; and finally, water which is discharged to the natural water body from the tailing reservoir reaches environment emission standards.By adopting the method disclosed by the invention, the problem that the deposited water load of the tailing reservoir is too heavy is solved and the acidic mine drainage water also can be treated bylow energy consumption; and meanwhile, in-situ or near-distance treatment of the acidic mine drainage water of the tailing reservoir can be realized. According to the method disclosed by the invention, the purification treatment of the acidic mine drainage water of the tailing reservoir is realized; meanwhile, the environment safety of the tailing reservoir can be improved; the resource utilization of tailings can be realized; and the implementation method has the advantages of simplicity and energy saving and has very high application value and application prospect.

The present invention relates to an apparatus and a system for treating acid mine drainage. The apparatus includes first and second reaction baths for receiving acid mine drainage, wherein the first and second reaction baths are provided with inlets and outlets and are separated from each other to prevent communication between acid mine drainages, an electrically connected anode and a cathode installed in each of the first and second reaction baths, and an electron transport medium for connecting the first reaction bath receiving the anode and the second reaction bath receiving the cathode. The electron transport medium blocks the transport of metal cations and allows the transport of electrons between acid mine drainages in the first and second reaction baths. Ferrous ions are oxidized to ferric ions in the acid mine drainage to precipitate hydroxides in the first reaction bath, and hydroxide ions are produced in the second reaction bath.

The invention discloses a coal mine drainage OLWS method. The method comprises the following steps: collecting mine drainage A in a drainage collecting pool; 2, adding a quantitative amount of the mine drainage A with the pH value of alpha to a natural oxidation system in order to form a sulfuric acid / ferric sulfate solution; 3, adding acid mine drainage B obtained in step 2 to a filter material neutralization system with a calcium carbonate-containing filter material as a main component in order to rise the pH value of acid mine tailing drainage; and 4, discharging mine drainage C obtained in step 3 into wetland, wherein a multi-matrix filler is placed in the wetland, and plants capable of easily absorbing the mine tailing drainage resistant component environment are planted, and the mine drainage C can effectively stay and can be adsorbed by the wetland. The method has the advantages of long action time, strong processing capability, high efficiency, convenient construction, low running cost and maintenance cost, and completely no power.

A process for treating acid mine drainage containing heavy metals and soluble contaminants is provided. In one embodiment, at least a metal cation is added to the acid mine drainage at a pre-select pH to form insoluble heavy metal complexes. In one embodiment, the metal cation is a trivalent metal ion, e.g., ferric iron such as in ferric sulfate. In another embodiment, a divalent metal ion such as in ferrous sulfate is used. After the removal of the heavy metal complexes, the effluent water is treated with at least a phosphate additive to remove remaining soluble contaminants, thus producing a treated water stream with reduced levels of contaminants.

The invention relates to a method for high-efficiency precipitation of soluble iron in acid mine drainage, belonging to the field of environment engineering technology. The method comprises the following steps: electrolyzing acid mine drainage rich in iron ions at a low voltage and allowing most trivalent iron ions to be reduced into divalent iron ions through gain and loss of electrons; and then oxidizing divalent iron ions by using acidithiobacillus ferrooxidans so as to produce a ferric hydroxysulfate mineral with good settleability and compact particles. After secondary reduction and secondary mineral formation, the total iron precipitation rate is increased to almost 80%. The method promotes removal of soluble iron and does not introduce other chemical components, and the obtained secondary mineral has good settleability. Compared with technology of the same kind, the method provided by the invention is more superior and has the advantages of low cost, safety, reliability, energy conservation and environment friendliness, and moreover, the secondary mineral can be used as an adsorption material for resourceful utilization.

The invention discloses a method for simultaneously treating refuse leachate and acidy mine drainage. The method is characterized by comprising the following steps: firstly, mixing refuse leachate with acidy mine drainage in proportion to form adjusting wastewater containing high-concentration COD and sulfate, and then introducing adjusting wastewater into a biological treatment system including an anaerobic reactor, an anoxic reactor and an aerobic reactor for treatment; and more than 80% of sulfate and 80%-90% of COD in drained water of the anaerobic reactor are removed by virtue of lots of anaerobic microorganisms. The anaerobic reactor is communicated with the anoxic reactor and the aerobatic reactor, the anoxic reactor is communicated with the aerobic reactor, the aerobic reactor is utilized for carrying out aerobic nitration reaction by virtue of a reflux ratio regulation process, and effluent flows back to the anoxic reactor to cause denitrification reaction, so that the removal rate of total nitrogen reaches almost 100%. By implementing the method, organic matters, sulfate and heavy metal ions in refuse leachate and acidy mine drainage can be efficiently removed, the denitrification is achieved, and the waste is treated by virtue of waste, so that the cost is relatively low.

The invention provides a method of reducing the sodium content of a water containing dissolved sodium ions, particularly a water with a sodium ion content of at least 100 ppm. Examples of such waters are effluents such as acid mine drainage and river waters. The method includes the steps of:(i) removing sodium, calcium and magnesium ions from the water by contacting the water with a cation exchange resin / s to capture sodium, calcium and magnesium ions thereon,(ii) treating the cation exchange resin / s of step (i) with nitric acid to produce an eluant containing sodium ions, calcium ions, magnesium ions nitrate ions and nitric acid,(iii) adding a carbonate to the eluant to precipitate the calcium and magnesium ions as calcium and magnesium carbonates;(iv) separating the precipitated carbonates from the eluant; and(v) treating the eluant from step (iv) to obtain a sodium and / or potassium nitrate product.

The invention discloses an in-situ ecological restoration method of an acid mine drainage (AMD) pollution lake / reservoir water body. A surface layer plant floating bed is combined with bottom layer sludge microbe buffer treatment to perform ecological restoration treatment on the AMD pollution lake / reservoir water body; excess sludge generated by conventional secondary town sewage treatment is added into the pollution lake / reservoir to automatically select the optimal dominant microbe groups for purifying the AMD, thereby avoiding microbe preservation, activation, inoculation, culture and other special complex and difficult links for treating microbes; and the excess sludge is recycled to provide an early nutrient carrier and buffer the acidity of the AMD. The surface layer cattail plant floating bed continuously provide carbon nitrogen and other nutrients and energy sources for the growth of the bottom layer microbes by using the growth secretory products and litters so as to form a self-sustaining ecological purification system, thereby avoiding the continuous addition of exogenous carbon nitrogen and other nutrients and greatly saving the cost.