61 results about "Metal precipitation" patented technology

The invention discloses a preparation method of a catalytic membrane for organic wastewater treatment, which comprises the following steps: dissolving polyvinylidene fluoride (PVDF), a pore-forming agent and plant polyphenol in an organic solvent, and stirring to obtain a membrane casting solution, wherein the PVDF accounts for 12-20%, the pore-forming agent accounts for 1-8%, and the plant polyphenol accounts for 1-6%; standing and defoaming the membrane casting solution, blade-coating the membrane casting solution on a support body to form a membrane, and performing phase inversion in a water bath to obtain the plant polyphenol modified PVDF membrane; and immersing the membrane in a 3-10 mmol / L metal chloride aqueous solution, and reacting at 40-80 DEG C for 6-48 hours, so that metal ions and polyphenol are coordinated and crosslinked, and a metal-polyphenol network layer is formed on the surface of the membrane and the inner walls of membrane pores, thereby obtaining the catalytic membrane. The catalytic membrane can activate peroxymonosulfate (PMS) and synergistically degrade organic pollutants in water under a differential pressure filtration working condition, active sites are anchored stably, metal precipitation is reduced, and flux and catalytic efficiency are both considered.

The invention discloses a method for separating and recycling phosphorus, iron and lithium in battery black powder, and relates to the technical field of battery recycling. The method comprises the following steps: carrying out acid leaching on battery black powder to obtain a battery black powder leaching solution and filter residues; an oxidizing agent is added into the battery black powder leaching solution, the pH of the solution is adjusted to 1.8-2.5, solid-liquid separation is conducted after the reaction is completed, and iron phosphate sediment and a lithium-containing solution are obtained; adjusting the pH value of the lithium-containing solution to 10-12, and carrying out solid-liquid separation after the reaction is completed to obtain a metal precipitate and a lithium sulfate solution; dissolving the iron phosphate precipitate in a sulfuric acid solution, adding a reducing agent to reduce ferric iron into ferrous iron, separating out ferrous sulfate by adopting an alcohol precipitation method or an ammonium sulfate crystallization method, and performing solid-liquid separation after the reaction is completed to obtain ferrous sulfate precipitate or ammonium ferrous sulfate crystals and mother liquor; and evaporating and concentrating the mother liquor, and extracting to obtain a phosphoric acid solution. According to the method, the three elements of phosphorus, iron and lithium in the battery black powder can be recycled, and the environmental problem caused by stacking of the lithium extraction slag can be avoided.

A method and equipment for recycling alumina red mud. First, the alumina red mud is added to a mixed acid of hydrochloric acid and sulfuric acid for reaction to dissolve metals such as iron, aluminum, calcium, sodium, and a small amount of zinc, copper, magnesium, etc., and the solid silicon dioxide is left to be separated as building materials or glass raw materials; after the solution is collected, ammonium bicarbonate is added to obtain aluminum, calcium, and some metal precipitates and separated. Iron and sodium remain in the solution and continue to react with sodium hydroxide to obtain iron hydroxide precipitate and separate out sodium salts. After evaporation of the concentrated solution, iron oxide is obtained as a raw material for steel production; the aluminum, calcium, and other metal precipitates are added to sulfuric acid with a concentration of 90-98% for reaction. After all are dissolved, the solution is subjected to membrane separation and then carbonates are added to obtain calcium carbonate precipitate as a raw material for cement production; after evaporation of the concentrated solution, high-purity alumina is obtained and sent to an aluminum processing plant to produce pure aluminum or aluminum alloy products; the separated sodium salt solution is evaporated to be used as industrial and agricultural salt; the acid mist and harmful gases in the reactor process are treated by an absorption tower and then discharged. The present invention can make full use of the iron oxide, alumina, and effective components of alumina red mud, solves the problem of environmental pollution caused by the large amount of piled-up alumina red mud at present, has a low cost, and is suitable for the current alumina production plants.

The invention provides a method for preferentially extracting gold and silver from lead anode slime, and relates to the technical field of precious metal recovery, firstly, silver, antimony and other valuable metals in the lead anode slime are leached into a solution through catalytic oxidation leaching in the presence of a protective agent, and gold is enriched in residues; then, silver is selectively precipitated from the leachate, and silver precipitation residues and a valuable metal solution are obtained; and finally, valuable metals in the solution are recovered by adding a neutralizer and a precipitator, the obtained leaching mother liquor can be returned for leaching after being supplemented with hydrochloric acid, and the valuable metal precipitates are used for recovering antimony and bismuth. The method changes the traditional lead anode slime treatment thinking of first impurity removal and second refining, has the characteristics of high gold and silver direct recovery rate (greater than 99.5%), high reaction speed (total consumed time is less than 1 h), low cost and no generation of waste residue and wastewater, and is expected to solve the problems of long gold and silver recovery process, low direct recovery rate, capital overstock and difficult treatment of arsenic and antimony-containing smoke in the existing lead anode slime treatment method. The method has remarkable economic and environmental benefits and a good application prospect.

The invention discloses an acid mine pollution treatment method based on microbial regulation and control, and belongs to the technical field of environmental protection engineering, and the acid mine pollution treatment method comprises the following steps: S1, screening and domesticating acid-resistant and heavy metal-resistant functional microbial communities; s2, constructing a sectional bioreactor, and filling the sectional bioreactor with a corresponding composite biological carrier; s3, inoculating the functional microbial community obtained by domestication in the step S1 into the sectional reactor constructed in the step S2, and carrying out biofilm culturing in simulated AMD; and S4, introducing AMD to be treated into the reaction system in the step S3, and regulating and controlling microbial activity through pH gradient regulation and dynamic supply of electron donors to realize heavy metal precipitation and water quality remediation. According to the method, closed-loop treatment of sulfate reduction, heavy metal precipitation and acid neutralization is achieved through the synergistic effect of microbial regulation and control and the functionalized biological carrier, and the problems of efficiency, cost and secondary pollution of traditional AMD treatment are solved.

The invention provides a method for purifying silicon from an organic silicon synthesis waste contact body and application of the method in preparation of a silicon-based alloy. The method comprises the following steps: pickling the waste contact body by using acid liquor; acid liquor is added into the silicon enriched material obtained through acid pickling separation, acid leaching slurry is obtained, the acid leaching slurry is diluted, and waste contact electrolyte is obtained; adjusting the pH value of the waste contact electrolyte to 5.5-6.5, and introducing the waste contact electrolyte into an electrolytic cell; introducing oxygen-containing gas near a cathode plate of the electrolytic bath, and introducing direct current on an electrode plate of the electrolytic bath to carry out electrolytic reaction; adjusting the pH value of the electrolyte in the electrolytic bath to 7.0-7.5, and continuing the electrolytic reaction to obtain a metal precipitate; and separating the liquid part and the precipitation part in the electrolytic bath, adding water into the precipitation part, fully stirring, and carrying out centrifugal separation, washing and drying treatment to obtain the silicon powder. According to the method, metal impurities and organic matters in the waste contact bodies can be effectively removed, high-purity silicon is obtained, and the high-quality silicon-based alloy is prepared.

The embodiment of the invention provides a self-heating type waste fan blade treatment method. The method comprises the following steps: providing the waste fan blade, and physically crushing the waste fan blade to obtain waste fan blade powder; the waste fan blade powder is burnt and pyrolyzed according to the preset weight ratio; performing vibration screening on the combustion residues to obtain glass fibers and ash, and performing vibration screening on the pyrolysis residues to obtain glass fibers and other solids; other solids are combusted to supply heat for pyrolysis and obtain combustion residues, and the combustion residues are subjected to vibration screening to obtain glass fibers and ash; carrying out chemical dissolution and gradient precipitation on the ash content to obtain a metal precipitate; and combustible materials, glass fibers and metal precipitates are recycled. According to the embodiment of the invention, the waste fan blade can be converted into high-value fuel, glass fiber and metal without extra energy input, solid components in a pyrolysis product are reasonably utilized, the energy utilization rate is increased, and the resource utilization degree of the waste fan blade is greatly improved.

The invention provides a method for restarting fatigue acid after surface treatment of a steel pipe and a plate, and belongs to the technical field of fatigue acid recycling in the stainless steel industry. The invention aims to solve the technical problems of insufficient purity of regenerated acid liquor, frequent replacement of new acid, high cost, large waste residue generation amount and complicated subsequent treatment caused by the fact that neutralization precipitation or ion exchange is mainly adopted in the traditional treatment method, but thorough separation is difficult. The method comprises the following steps: collecting fatigue acid after surface treatment of steel pipes and plates in a sedimentation tank, adding a supplement containing a metal precipitant and a flocculant to complete precipitation of precipitates, separating supernatant of the precipitates after precipitation in the sedimentation tank, putting the extracted supernatant into use again and generating new fatigue acid, and recycling the new fatigue acid. And repeating the steps to complete the restart of the fatigue acid.

The utility model discloses a device for electrokinetic remediation of heavy metal contaminated soil, which comprises an electrolysis chamber and a power supply, and an anode chamber and a cathode chamber are respectively arranged on two opposite sides in the electrolysis chamber; an anode plate is arranged in the anode chamber, a cathode plate is arranged in the cathode chamber, and the anode plate and the cathode plate are respectively connected with a power supply; an anion permeable membrane is vertically arranged on the side, close to the cathode chamber, in the electrolysis chamber, and the anode chamber and the cathode chamber are located on the two opposite sides of the anion permeable membrane respectively. According to the device for electrokinetic remediation of the heavy metal contaminated soil, metal precipitates are gathered on one side of the anion permeable membrane and located outside the cathode chamber, a dosing pipe of the cathode chamber cannot be affected, pipe loss is reduced, and electrokinetic remediation efficiency is improved.

The application provides a metal recovery device in electroplating wastewater, and relates to the technical field of electroplating wastewater treatment.The metal recovery device comprises a recovery tank, at least one storage cylinder assembly and two barrier agitation structures.The recovery tank is respectively provided with an inlet end and an outlet end on both sides, and a recovery discharge part is arranged at the center of the bottom wall.Two symmetrical material guiding slopes are arranged on the inner bottom wall.The barrier agitation structures are slidably arranged on the upper frame body, and are driven by an agitation driving assembly to move synchronously and reversely.The barrier agitation structures trigger flocculating agent feeding and agitate waste liquid synchronously when moving below the storage cylinder assembly.The bottom of the barrier agitation structures contacts with the material guiding slopes to form a barrier when moving to both ends of the recovery tank.The metal recovery device realizes linkage of intermittent flocculating agent feeding and waste liquid agitation through reciprocating movement of the barrier agitation structures, and automatically blocks metal precipitates when discharging liquid, so that the metal recovery rate and the precipitate collection efficiency are effectively improved, and the structure is compact and convenient to operate.

The utility model discloses a nickel-lithium solution recovery device which comprises a filter storage device, a nickel-lithium metal precipitation separation device, a deamination and weight removal device, a concentration precipitation device, a concentration precipitation device and a sodium sulfate crystallization and solution recycling device which are sequentially connected in series, wherein the filtering and storing device is used for removing solid impurities and temporarily storing a nickel-lithium solution; the concentration device is used for concentrating the nickel-lithium solution; the nickel-lithium metal precipitation and separation device is used for crystallizing and precipitating nickel metal and separating the nickel metal from the solution so as to obtain a lithium solution; the deamination and heavy metal removal device is used for removing ammonia and heavy metal; the concentration and precipitation device is used for concentrating the lithium solution and reacting with sodium carbonate to generate lithium carbonate separated from the lithium solution; the sodium sulfate crystallization and solution recycling device is used for concentrating to generate anhydrous sodium sulphate, and the residual lithium-containing solution is returned to the previous step for cyclic precipitation separation to obtain lithium carbonate. Through the arrangement, nickel and lithium metals in the nickel-lithium solution can be recycled respectively.

The invention provides a diaphragm adhesive tape and a preparation method thereof. The diaphragm adhesive tape comprises a functional layer and an adhesive layer, the functional layer comprises a polyolefin coating, and the adhesive layer is arranged on the surface of the polyolefin coating; wherein the adhesive layer comprises an acrylate polymer. According to the invention, the acrylate polymer with a specific molecular structure is selected to be compounded with the polyolefin coating, so that not only are the bonding strength and interface stability of the whole diaphragm adhesive tape in an electrolyte remarkably improved, but also the wetting ability and distribution uniformity of the electrolyte on the surface of the adhesive tape are remarkably enhanced; and therefore, the migration efficiency of ions in the electric circulation process is improved, and the risk of metal precipitation at the bent corners of the pole pieces of the battery is effectively inhibited.

This invention discloses a green recycling and precious metal extraction method for lead-free printed circuit boards, belonging to the field of precious metal extraction technology. The method involves first freezing the circuit board with liquid nitrogen, then crushing and air-separating it under an alternating magnetic field. The remaining particles are then soaked in a composite organic acid solution, treated with a combination of ultrasound and microwave, rinsed, and floated. The metal particles are dissolved in a mixture of nitric acid and hydrogen peroxide, and a composite precipitant is added to precipitate the precious metals. The precipitate is reduced with hydrogen to obtain crude precious metals, which are then electrolytically refined. After refining, a composite anti-oxidation film is deposited. Finally, wastewater and waste gas are treated using a combination of methods for environmental protection, achieving green recycling and efficient extraction of precious metals. The optimized coordination of each step in this invention improves the metal recovery rate and purity, resulting in refined precious metals with a purity exceeding 99.95% and an antioxidant capacity increased by 30%-50%. The environmentally friendly treatment effectively reduces pollution and can be used in high-end industries, offering both economic and environmental benefits.

A process for preparing a catalyst, as well as a catalyst, the catalyst comprising an oxygen evolution reaction electrocatalyst OER, a hydrogen oxidation reaction HOR electrocatalyst, and a particulate solid support are described. The OER electrocatalyst and the HOR catalyst are both supported on the particulate solid support. The OER is deposited from an aqueous mixture comprising a particulate solid support and a halide free metalate which comprises iridium and / or ruthenium. The pH of the mixture is reduced to ≤7 to precipitate the oxygenated metal into the solid particulate support. In the process, the OER electrocatalyst is deposited before the HOR electrocatalyst. The catalyst may be incorporated into a catalyst coated membrane (CCM) and used in a fuel cell. [Figure 1a]

The invention relates to the technical field of wastewater treatment, in particular to a ternary precursor washing wastewater filtering device which comprises a supporting seat, a supporting cylinder is fixedly mounted in the supporting seat, and an equipment cylinder is fixedly mounted at the upper end of the supporting cylinder through an arranged supporting column; a centrifugal filtering mechanism used for carrying out classified screening on metal precipitates in the ternary precursor washing wastewater through the centrifugal filtering effect is arranged in the supporting cylinder, and a driving mechanism used for providing power for the centrifugal filtering mechanism is arranged in the supporting cylinder and the equipment cylinder jointly. Rapid centrifugal filtration of metal precipitates in the ternary precursor washing wastewater is completed by adopting integrated operation of centrifugal filtration, graded screening and anti-blocking, and meanwhile, effective graded screening is performed on the internal metal precipitates through the centrifugal filtration effect, so that the metal precipitates with different sizes are graded; meanwhile, in the centrifugal filtration process, scrubbing and knocking are utilized, so that metal sediment adhesion substances on the filter screen are effectively removed, and the filter screen is kept clean.

The invention discloses a method and a device for sulfur recovery driven metal capture coupled anaerobic bioelectrochemistry treatment of high-salt retired lithium battery discharge wastewater. The anaerobic bioelectrochemical device adopts an up-flow anaerobic sludge blanket reactor and is externally connected with a direct-current stabilized power supply, a reaction area is inoculated with anaerobic granular sludge, electrodes are made of carbon brush materials and are arranged up and down, and the reaction process is under an anaerobic condition; the front end of the anaerobic bioelectrochemical device is connected with a metal capture tank in series, the backflow water of the anaerobic bioelectrochemical device and the high-salt retired lithium battery discharge wastewater are mixed in the metal capture tank, and sulfide in the backflow water and metal in the wastewater form precipitates. By adopting the method to treat the retired lithium battery discharge wastewater with the salinity greater than 4%, organic matters, sulfates and metals in the wastewater can be effectively removed. The method is high in treatment efficiency and low in material consumption and energy consumption, meanwhile, methane and metal precipitates generated by a process system can be recycled, economic value is generated, and a new way is provided for treatment of the metal-containing high-salt organic wastewater.

The invention relates to a method for recovering one or more metals selected from the group consisting of technetium, ruthenium, palladium and rhenium from an aqueous solution, comprising: adding to said solution a reagent to precipitate the one or more metals in the solution, and then collecting the precipitate thus formed, characterized in that the reagent comprises or consists of 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, or 1, 3-butanediol. The invention relates to a composition consisting of a mixture of 1, 10-phenanthroline and a nickel (II) salt selected from the group consisting of nickel (II) nitrate and nickel (II) sulfate. Application: recovering all or part of technetium, ruthenium and / or palladium from an aqueous solution of the fission product prior to an operation intended to vitrify the fission product; and recovering all or part of ruthenium, palladium and / or rhenium from the solution obtained by pickling the industrial and / or municipal waste with nitric acid.

The embodiment of the utility model provides acid mine wastewater treatment equipment. The acid mine wastewater treatment equipment comprises a reactor and a gas supply device, the reactor comprises a container and a membrane assembly arranged in the container, the membrane assembly is used for attaching a biological membrane and provided with a gas inlet, and the gas supply device is communicated with the gas inlet of the membrane assembly and used for supplying a gaseous electron donor to the membrane assembly. According to the acid mine wastewater treatment equipment disclosed by the embodiment of the utility model, the biological activity of sulfate reducing bacteria is relatively strong, the sulfate reducing efficiency is relatively high, metal precipitates are easy to precipitate and collect, and the difficulty and the cost of callback to neutrality are relatively low and even callback to neutrality is not needed.

The invention discloses a metal collaborative recovery and cascade purification method, which comprises the following steps: classifying and pretreating metals, collecting metal-containing materials from wastes, carrying out preliminary classification according to metal types, treating bulk materials into proper particle sizes through physical methods of crushing, screening and grinding, and carrying out chemical leaching and dissolving. The method comprises the following steps: carrying out chemical leaching on metal by using an acid, alkali and saline solution, dissolving target metal and forming a metal ion solution, adding a precipitator into the metal ion solution to separate out the target metal in the form of precipitate, separating the precipitate from clear liquid by virtue of a filtering and centrifuging method, and collecting metal precipitate; according to the method, the whole-process recovery and purification of the metal from waste to a high-purity product are realized through a cascade process of classification pretreatment, chemical leaching, precipitation separation, washing and drying and extraction refining, and compared with traditional pyrogenic process smelting, a high-temperature environment is not needed, and the energy consumption and the treatment cost are remarkably reduced.

Disclosed is a method for recycling metal-chelates by separating the metal or metal ion from the chelate by forming a metal salt or metal precipitate apart from the chelator. In various embodiments, gadolinium-chelates, which are used as MRI contrast agent and which create vial hold-up material that is otherwise discarded, are acid or solvent treated to promote separation of the gadolinium from the chelate for downstream sale or further processing.

Provided are an electrolyte solution capable of improving the durability of an electrochemical device, reducing the amount of gas generation, and reducing the amount of metal deposition, and an electrochemical device and a secondary battery using the same. An electrolyte solution containing at least one compound represented by general formula (1). Rf1OR (1) (Rf1 is a fluoroalkyl group having 1-5 carbon atoms, and R is K or Na).

Improved methods for the removal of heavy metals, in particular cadmium, from an aqueous phosphoric acid containing composition, wherein an organothiophosphorous heavy metal precipitating agent and an ionic polymeric surfactant, particularly a cationic polyacrylamide copolymer surfactant, are both added to a phosphoric acid containing composition, particularly under vigorous mixing conditions, such as between 500 and 700 rpm. The ionic polymeric surfactant promotes the precipitation of the heavy metals. More in particular, the phosphoric acid containing composition is obtained by the acid digestion of phosphate rock, preferably by nitric acid, sulfuric acid, or a combination thereof.

The application of a long-chain nitrogen-containing organic cation salt compound in the aspect of being used as a platinum group metal precipitant and a platinum group metal recovery method belong to the technical field of recycling of secondary resources of noble metals.The platinum group metal precipitant is mixed with an aqueous solution containing platinum group metal (palladium, platinum, rhodium, iridium) chloride complex ions, and the electrostatic effect of the long-chain nitrogen-containing organic cation salt in the precipitant on the platinum group metal chloride complex ions and the hydrophobic effect of the alkyl chain are utilized to precipitate the platinum group metal ions, so that the corresponding platinum group metal is obtained through solid-liquid separation and calcination.The present application provides an effective recovery method, which significantly improves the recycling efficiency of noble metal resources.The present application solves the technical problems of high residual concentration of tail liquid metal and large amount of precipitant in the previous precipitation recovery process, has the advantages of high recovery efficiency of noble metal, simplified process flow, environmental friendliness, improved resource utilization rate and the like, and provides an innovative solution for efficient recycling of platinum group metal resources.

The application discloses a system for using a chemical precipitation method of magnesium oxide, comprising a slurry preparation module and a reaction module. The slurry preparation module comprises pulp preparation units; the number of the pulp preparation units is 1-4, and the pulp preparation units comprise dispersion activation devices; the input end of the most upstream pulp preparation unit is provided with a first flow control device and a second flow control device, and magnesium oxide powder and pulp preparation liquid are continuously input into the most upstream pulp preparation unit through the first flow control device and the second flow control device at a controlled flow rate and are mixed; and the output end of the slurry preparation module continuously outputs magnesium oxide slurry. The reaction module is arranged downstream of the slurry preparation module; after the magnesium oxide slurry is output from the slurry preparation module, the magnesium oxide slurry is continuously input into the reaction module to implement a precipitation reaction. The pulp preparation liquid comprises process water and / or a pre-reaction liquid capable of being used for the precipitation reaction. The application can be used to realize that a metal precipitation reaction is efficiently and stably performed.

The application discloses a chemical precipitation method using magnesium oxide and a metal hydroxide product, and the chemical precipitation method comprises the following steps: S1, obtaining a pre-reaction solution capable of being used for a precipitation reaction, and obtaining a pulp solution containing ions of a target metal in the pre-reaction solution; S2, mixing magnesium oxide powder and the pulp solution, and obtaining a first slurry through a pulp treatment; and S3, putting the first slurry into a reactor to perform a precipitation reaction, and generating a precipitated slurry containing a metal hydroxide of the target metal. In the magnesium oxide powder, a first part of the magnesium oxide powder has a higher average activity than that of the whole magnesium oxide powder. The method is used to solve the problem of serious activity attenuation of the magnesium oxide slurry, improve the precipitation efficiency of the target metal in the precipitation reaction, increase the content of the target metal in the metal hydroxide product, and reduce the single consumption of the magnesium oxide and the content of magnesium impurities in the product.

The application relates to the technical field of semiconductor material manufacturing, and discloses an N-type monocrystalline silicon wafer diffusion impurity absorption optimization method, which comprises the following steps: removing surface contaminants and tiny defects by pretreating an N-type monocrystalline silicon wafer; forming an impurity absorption layer on at least one surface of the pretreated N-type monocrystalline silicon wafer; performing diffusion annealing treatment on the N-type monocrystalline silicon wafer with the formed impurity absorption layer, and removing the impurity absorption layer material on the N-type monocrystalline silicon wafer after the diffusion annealing treatment; and completing the N-type monocrystalline silicon wafer diffusion impurity absorption optimization work. The impurity absorption layer formed on the surface of the silicon wafer can effectively capture and fix heavy metal impurities and defects, such as oxygen precipitation and metal precipitation, which may be generated in the subsequent process of the silicon wafer, so as to prevent the impurities and defects from causing adverse effects on the performance of the silicon wafer. The diffusion annealing treatment further promotes the diffusion of the impurities and the impurity absorption capacity of the impurity absorption layer, and ensures the effective removal of the impurities.

The invention discloses application of a nitrogen-containing surfactant as a platinum group metal precipitator and a platinum group metal recovery method, and belongs to the technical field of precious metal secondary resource recycling. The method comprises the following steps: adding a water-soluble nitrogen-containing surfactant into an acidic aqueous solution containing platinum group metal ions, carrying out a stirring reaction, standing and settling, and collecting a precipitate by adopting centrifugation or filtration; and then carrying out high-temperature heat treatment in a specific atmosphere to obtain the high-purity platinum group metal elementary substance. The nitrogen-containing surfactant is selected from one or a combination of more of quaternary ammonium salt containing aromatic side chain or short chain alkyl, alkyl quaternary ammonium salt with specific anions, amine oxide type surfactant and betaine type surfactant, and is subjected to ionic association with platinum group metal complex anions and induces aggregation and sedimentation; and high-selectivity capture of ruthenium, rhodium, palladium, osmium, iridium and platinum is realized. The method provided by the invention still has stable precipitation efficiency in a wide acidity range, and can reduce the consumption of the precipitator and the residual noble metal in the tail liquid.

The application discloses an improved SCC target cleaning system and method for wafer backside contamination, including: constructing a backside chemical solution flow field optimization and edge wetting consistency control mechanism, achieving uniform chemical solution coverage through multiple groups of ring-shaped spraying units and supplementary jet flow mechanisms; preparing SCC cleaning chemical solution that inhibits residue and metal precipitation, achieving metal ion complexing with a multi-component formula of organic solvents, complexing agents, surfactants, and corrosion inhibitors; establishing an intelligent control model for backside stain tracing and process parameter matching, achieving adaptive process parameter matching based on a contamination characteristic database and a deep neural network; performing targeted cleaning operations according to the optimal parameter combination; evaluating cleaning effect and optimizing process to achieve continuous improvement. The system includes a cleaning cavity, multiple groups of ring-shaped spraying units, a rotary drive device, an optical detection device, and a cleaning waste liquid recovery and treatment unit. The above technical solution can achieve the beneficial effects of backside cleaning uniformity improvement, effective inhibition of metal impurities, intelligent targeted cleaning, and overall yield improvement.

The present disclosure discloses a method for converting a solid hazardous heavy metal-containing composition into a solid non-hazardous heavy metal-containing composition and an aqueous composition essentially free of heavy metal. The method comprises the steps of a) mixing and dissolving the solid hazardous heavy metal-containing composition with an acid solution, thereby obtaining an hazardous heavy metal acid composition; b) precipitating the heavy metal from the hazardous heavy metal acid composition by: measuring the pH of the acid composition after a 13-fold dilution by volume using water, and adjusting the pH of the solid hazardous heavy metal-containing composition to at least 0.9 if the measured pH is below 0.9; and by reacting the hazardous heavy metal acid composition with a heavy metal-precipitation agent; and c) precipitating the heavy metal from the hazardous heavy metal acid composition by adjusting the pH value of the composition to a value of at least 0.9 if the pH measured in step b) is below 0.9 and by reacting with a heavy metal- precipitation agent; and d) separating out the heavy metal precipitate from the aqueous supernatant, whereby the solid inert heavy metal-containing composition comprises the heavy metal precipitate and the aqueous composition essentially free of heavy metal comprises the aqueous supernatant. The heavy metal-precipitation agent comprises a diorgano-dithiophosphinic acid or the alkali metal or ammonia salts thereof represented by Formula (1), Formula (1) wherein R is a linear or branched hydrocarbon group selected from alkyl, aryl, alkylaryl, or aralkyl, and wherein the hydrocarbon group contains 3 to 20 carbon atoms, and M is H, alkali metal or ammonia. The present disclosure further relates to the use of the heavy metal-precipitation agent for converting the solid hazardous heavy metal-containing composition into the solid non-hazardous heavy metal- containing composition and the aqueous composition essentially free of heavy metal.

The utility model relates to metal extraction technical field, and disclose a kind of reaction box of rare and precious metal extraction, including box, the top outer wall of the box is equipped with the mouth of avoiding position, the tank for metal extraction reaction is slidably connected in the mouth of avoiding position, the bottom inner wall of the box is fixedly connected with U-shaped seat, the top inner wall of the U-shaped seat is fixedly connected with driving motor, the one end of driving motor output shaft is connected with the recessed block of the top outer wall of U-shaped seat by key, the bottom inner wall of the tank is rotatably connected with the shaft of bearing.The utility model is by separating the tank with the tank and being separable, the tank can be conveniently taken out after extraction operation, to observe the situation of internal metal precipitation, and by the setting of recessed block and connecting block, the tank can be conveniently taken out while not affecting the driving effect of internal stirring component.