12 results about "Metal precipitation" patented technology

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.

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 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 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.

This application provides a method for purifying silicon from waste catalysts used in organosilicon synthesis and its application in preparing silicon-based alloys. The method includes: acid washing the waste catalysts with an acid solution; adding acid to the silicon-enriched material obtained from the acid washing separation to obtain an acid leaching slurry, and diluting the acid leaching slurry to obtain a waste catalyst electrolyte; adjusting the pH value of the waste catalyst electrolyte to 5.5-6.5, and introducing the waste catalyst electrolyte into an electrolytic cell; introducing oxygen-containing gas near the cathode plate of the electrolytic cell, and conducting an electrolytic reaction by applying direct current to the electrode plates of the electrolytic cell; adjusting the pH value of the electrolyte in the electrolytic cell to 7.0-7.5, and continuing the electrolytic reaction to obtain a metal precipitate; separating the liquid portion and the precipitate portion in the electrolytic cell, adding water to the precipitate portion, stirring thoroughly, and then centrifuging, washing, and drying to obtain silicon powder. This application can effectively remove metallic impurities and organic matter from waste catalysts, obtain high-purity silicon, and prepare high-quality silicon-based alloys.

The application provides a method for CO2 capture and mineralization and metal resource recovery, comprising: a CO2 absorption step: using an absorbent solution to absorb CO2 in a gas to be treated to obtain a CO2-rich solution; a CO2 mineralization and absorbent regeneration step: reacting the CO2-rich solution with alkaline solid waste to realize CO2 mineralization and absorbent regeneration, performing first solid-liquid separation on the system after reaction, and returning the separated liquid as a regenerated absorbent solution to the CO2 absorption step; and a metal mineralization step: monitoring the total concentration of metal ions in the CO2-rich solution, and in the case that the total concentration of metal ions in the CO2-rich solution is greater than or equal to a first concentration threshold, diverting a part of the CO2-rich solution to perform a metal precipitation reaction with CO2 to obtain a metal carbonate or a metal basic carbonate. The scheme of the application realizes efficient recycling of metal resources in solid waste, while reducing or even avoiding the blockage caused by metal ion precipitation in the CO2 absorption process.

This invention relates to the field of chemical purification technology, specifically to a method for improving the purity of hydrogen peroxide. The method includes sequentially subjecting an industrial-grade hydrogen peroxide solution to low-temperature pre-filtration, low-metal precipitation activated carbon fiber organic impurity capture, bifunctional confined trapping membrane contact adsorption purification, ceramic nanofiltration, and terminal microporous filtration; the surface of the bifunctional confined trapping membrane is immobilized with N-methyl-D-glucosamine groups and 1-aminoethylidene diphosphonic acid. This method can simultaneously reduce the content of organic impurities, metal ions, borosilicate impurities, and particulate matter in hydrogen peroxide, and reduce the risk of material leaching and hydrogen peroxide decomposition, making it suitable for the preparation of high-purity hydrogen peroxide.