46 results about "Selective leaching" patented technology

The invention relates to a method for recovering valuable components from high-copper and high-iron complex gold extraction broken carbon roasting slag. The method comprises the following steps: grinding and grading: grinding and grading a material to be treated into a fine material with the particle size of-0.074 mm accounting for 70%-80%; flotation decarburization is conducted, specifically, primary roughing is conducted on the fine material slurry, carbon-containing concentrate and tailings are obtained, and the carbon-containing concentrate is returned to an original roasting ashing system to be roasted again to obtain concentrate roasting slag; selective leaching of copper: feeding the tailings and the concentrate roasting slag into an ammonia-chlorine solution for pre-leaching to obtain copper-containing leaching liquid and leaching slag; first-stage preferential leaching is conducted, specifically, the leaching residues are fed into a cyaniding system to be subjected to first-stage preferential leaching, and a gold and silver pregnant solution and first-stage leaching residues are obtained; second-stage intensified leaching is conducted, specifically, the first-stage leaching residues are subjected to second-stage intensified leaching, and gold and silver pregnant solution and second-stage leaching residues are obtained; and recovery of element copper: conveying the copper-containing immersion liquid to a copper recovery system for distillation to obtain ammonia water and a copper hydroxide precipitate. According to the method, efficient comprehensive recovery of gold, silver and copper in the high-copper-iron complex gold extraction broken carbon roasting slag is achieved.

The invention relates to a porous nickel-iron alloy integrated electrode and a preparation method and application thereof, and belongs to the technical field of electrochemistry. The preparation method comprises the following steps: carrying out cleaning pretreatment on a stainless steel mesh substrate; then electro-deposition is carried out in a solution containing ferric salt and nickel salt, and a nickel-iron alloy layer is formed; carrying out secondary electro-deposition in a solution containing zinc salt, and carrying out high-temperature calcination treatment to obtain a nickel-iron-zinc alloy; and finally, the zinc component is removed through selective corrosion of an alkaline solution, and the nickel-iron alloy integrated electrode with the porous structure is formed on the stainless steel mesh. The method is controllable in process, and a porous structure which is high in specific surface area and beneficial to mass transfer is effectively constructed through step-by-step electro-deposition, calcination and corrosion treatment. The obtained integrated electrode can be directly used as an alkaline water electrolysis oxygen evolution reaction (OER) anode, shows high electrocatalytic activity and stability, and is suitable for the fields of water electrolysis hydrogen production and the like.

The invention relates to the technical field of hydrometallurgy, in particular to a selective leaching method of alkaline hydroxide ore, which comprises the following steps: fully mixing the alkaline hydroxide ore, an ammonium leaching agent and water to react, and obtaining reaction slurry after the reaction is finished; carrying out solid-liquid separation on the obtained reaction slurry to obtain a leaching solution I and a leaching residue I, and collecting the leaching solution I; s3, mixing the leached residues I with water for slurrying to obtain leached residue slurry; and S4, an acid leaching agent and a reducing agent are added into the leaching residue slurry under the conditions of heating and stirring, solid-liquid separation is conducted after full reaction, second leaching liquid and second leaching residues are obtained, and the second leaching liquid is collected. According to the leaching method, the follow-up impurity removal difficulty can be reduced while the leaching rate of cobalt, manganese and nickel of the alkaline hydroxide ore can be increased.

Aiming at the problem of low resource utilization value of the existing copper slag, the invention discloses a method for resourceful treatment of the copper slag, through a pyrogenic process and wet process mineral separation coupling method of high-temperature reduction, selective corrosion, magnetic-gravity combined separation and selective leaching, the transformation form and trend of key elements are accurately regulated and controlled, and the utilization rate of the copper slag is improved. The purposes of extracting lead, zinc, iron, copper and silicon elements in the copper slag step by step and converting the elements into corresponding high-value products are achieved. In addition, through process optimization and improvement, a low-temperature reaction system and a reagent cyclic regeneration mechanism are adopted, energy and chemical consumption is effectively reduced, generation of secondary hazardous waste is basically eradicated, and a new solution path is provided for green, high-value and efficient utilization of metallurgical solid waste.

The present invention provides a method for selectively leaching and removing impurities from nickel and cobalt hydroxide. The method comprises: slurrying nickel and cobalt hydroxide raw materials, then sequentially adding acid and nickel and cobalt hydroxide to adjust the pH value, and obtaining a pre-leached liquid and a pre-leached residue after leaching; slurrying the pre-leached residue, then sequentially adding acid, a reducing agent, and nickel and cobalt hydroxide to obtain a first leachate and a first leach residue after leaching; slurrying the first leach residue, then adding acid, and obtaining a second leachate and a second leach residue after leaching; wherein the second leachate contains copper ions, iron ions, and aluminum ions; mixing the second leachate with a pH adjusting agent, and obtaining a third leachate and a third leach residue after leaching; wherein the third leach residue contains iron and aluminum elements; mixing the third leachate with acid, then adding a copper reducing agent to carry out a reduction reaction, and obtaining a fourth leachate and a fourth leach residue after leaching. This method can improve efficiency and save costs.

The invention relates to the technical field of comprehensive utilization of metallurgical resources, and discloses a method for ferrovanadium enrichment and acid recycling of vanadium-containing steel slag tailings, the vanadium-containing steel slag tailings are used as raw materials, firstly, an acid leaching method is adopted for treating the vanadium-containing steel slag tailings, then, a ferrovanadium enrichment auxiliary is added for enriching vanadium and iron, finally, solid-liquid separation is conducted, the solid is a ferrovanadium enriched material, and the ferrovanadium enriched material is recycled. And adjusting the pH value of the filtrate, and recovering calcium. According to the method, selective leaching, reaction thermodynamics and reaction kinetics macroscopic regulation and control are combined, trace leaching, non-leaching or re-precipitation of vanadium and iron and efficient leaching of calcium and magnesium are achieved, the enrichment degree of vanadium and iron is greatly improved while the enrichment cost of vanadium and iron is reduced, and the grade of vanadium and iron in solid slag is higher; in addition, recycling of valuable elements of calcium and magnesium and cyclic utilization of the leaching acid liquor are achieved through follow-up treatment, and good environment-friendly benefits and economic feasibility are achieved.

The invention relates to the field of metal material surface modification technologies and cooker manufacturing, in particular to a preparation method of a coating-free hydrophobic low-carbon steel non-stick iron pan. Comprising the following steps: step 1, selecting a base material: selecting low-carbon steel with the carbon content of less than or equal to 0.2% as the base material; secondly, heat treatment is conducted, specifically, the base material in the first step is subjected to two-stage heat treatment, austenitizing heat preservation is conducted firstly, then air cooling is conducted to the room temperature, and then low-temperature tempering is conducted; and step 3, surface corrosion modification: preparing a corrosive liquid which is a mixed system of ethanol with the volume fraction of 96% and nitric acid with the volume fraction of 4%, and soaking the base material subjected to heat treatment in the step 2 in the ethanol-nitric acid mixed corrosive liquid prepared by the method under the condition of normal temperature. According to the method, the grain size and the grain boundary state of the base material are optimized through the optimized heat treatment process, a uniform and compact micron-sized rough grain boundary structure is formed on the surface of the base material through the selective corrosion effect of the corrosive liquid on the grain boundary, and the non-stick effect is achieved; the process is simple and suitable for large-scale industrial popularization.

This invention discloses a method for oxidative leaching of selenium and mercury from copper smelting acid sludge, belonging to the field of solid waste comprehensive utilization technology. The leaching system in the oxidative leaching is a ternary synergistic oxidative leaching system of "sulfuric acid-sodium chloride-oxidant". Under the action of the synergistic leaching system, efficient and selective leaching of selenium and mercury from copper smelting acid sludge is achieved. This method avoids the corrosion of equipment by volatile acids and the problem of excessive oxidation of the nitric acid system, and significantly improves the stability of the oxidation process and the efficiency of reagent utilization, ultimately achieving multiple goals such as efficient recovery of valuable metals, low-carbon and energy-saving process flow, and compliant and harmless treatment of hazardous waste.

This invention relates to the field of metal production or smelting technology, and discloses a method for the commercialization of iron and manganese elements in ferromanganese alloys. The method employs a two-stage leaching process for selective leaching of ferromanganese alloys, comprising: Step S1, adding water to the ferromanganese alloy and / or neutralized leaching residue, introducing a first oxidant, adding a sulfur-containing reagent, adding sulfuric acid, performing a first-stage catalytic oxygen leaching, and separating the solid and liquid to obtain a first leaching solution and iron slag; Step S2, adding ferromanganese alloy to the first leaching solution, adding water, performing a second-stage neutralized leaching, introducing a second oxidant, separating the solid and liquid to obtain a second leaching solution and neutralized leaching residue, and returning the neutralized leaching residue to step S1. This invention achieves the separation of manganese and iron, with a short process flow, low cost, and high efficiency, facilitating industrial production; moreover, iron is directly converted into iron oxide precursor, obtaining high-quality iron products at low cost, and manganese can be made into manganese sulfate solution for the production of battery-grade manganese sulfate, providing a new approach for the preparation of lithium-ion battery cathode precursor materials.

The invention discloses a method for selectively leaching nickel in nickel-containing copper concentrate, belongs to the technical field of hydrometallurgy, and solves the problems of low direct recovery rate of nickel and high nickel content in a finished product in the existing pyrogenic treatment of the nickel-containing copper concentrate. The leaching method comprises the following steps: mixing nickel-containing copper concentrate with sulfuric acid, continuously stirring at the temperature of 90 DEG C, selectively leaching nickel through normal-pressure leaching, carrying out nickel removal reaction, finally extracting leached liquid, then adding an oxidizing agent into the leached liquid to finally precipitate Fe < 3 + >, filtering to obtain nickel-containing filtrate, slowly adding NaOH into the nickel-containing filtrate, continuously stirring, and filtering to obtain the nickel-containing filtrate. And adjusting the pH value of the solution to be greater than or equal to 8.5 to precipitate nickel, and discharging wastewater. The method is convenient to operate and excellent in nickel removal effect, nickel is recovered in advance through normal-pressure selective leaching of nickel in the nickel-containing copper concentrate, the recovery rate of nickel in the nickel-containing copper concentrate and the direct recovery rate of copper are effectively increased, the production cost is reduced, meanwhile, the quality of a cathode copper plate is improved, and high practicability is achieved.

The invention discloses a preparation method of a multistage porous NiMnAl alloy / MnAl layered double metal hydroxide heterojunction electrocatalyst pole piece for a lithium-carbon dioxide battery positive electrode. Selective corrosion of Al in Ni-Mn-Al precursor alloy is regulated and controlled through a dealloying technology, and the NiMnAl alloy / MnAl layered double-metal hydroxide heterojunction electrocatalyst with graded pore channels and a large number of nanometer heterogeneous interfaces is successfully constructed along with a limited oxidation reaction of low-coordination Al and Mn atoms. The multi-stage porous NiMnAl alloy substrate is composed of multiple intermetallic compounds and nickel nanocrystals, crystal boundaries are interlaced in a staggered mode, the multi-stage porous NiMnAl alloy substrate is cross-linked with porous MnAl layered double-metal hydroxide nanosheets to form a rich cross-dimensional heterogeneous interface, and the intrinsic catalytic activity of the catalyst is improved. The spongy metal structure provides sufficient mass transfer pore channels, a stable electron transport network and a large specific surface area beneficial to exposure of a large number of catalytic sites, and the apparent catalytic activity of the catalyst is further improved. Finally, through the interface synergistic effect between the two-dimensional porous MnAl layered double-metal hydroxide nanosheet and the three-dimensional multi-stage porous NiMnAl alloy, the carbon dioxide electrochemical reduction and precipitation reaction kinetics is remarkably improved. Besides, the preparation process of the catalyst has remarkable advantages, the adopted method is simple and clear in operation process, high in production efficiency, excellent in reproducibility of experimental results and low in preparation cost, industrial amplification production can be realized, and a solid foundation is laid for large-scale popularization and application.

The application relates to the technical field of alloy corrosion technology, and particularly discloses a corrosion solution for CMSX-4 nickel-based single-crystal high-temperature alloy and a preparation and use method thereof. The corrosion solution is composed of the following components: perchloric acid, concentrated nitric acid, distilled water and liquid soap. The ratio of the components is as follows: perchloric acid: nitric acid: distilled water: liquid soap is equal to 8-12 ml: 8-12 ml: 30 ml: 1 drop (0.04-0.06 ml) of liquid soap. The corrosion solution can not only quickly and efficiently corrode the metallographic structure of the CMSX-4 alloy, but also can obtain higher contrast by selectively corroding the gamma prime phase compared with the existing traditional corrosion solution. The microstructure resolution under a scanning electron microscope is much higher than that of other corrosion methods, and even reaches the level of a transmission electron microscope. The nanoscale secondary gamma prime phase and phase interface groove morphology can be clearly observed, which has important significance for the characterization and quantitative statistics of the nanoscale microstructure under a large field of view.

The invention discloses a corrosive agent for the grain size of quenched and tempered steel, application of the corrosive agent and a display method for the grain size of the quenched and tempered steel, and particularly relates to the technical field of metallographic detection. A corrosive agent for the grain size of quenched and tempered steel is composed of hydrochloric acid with the concentration of 36%-38% and the volume of the hydrochloric acid accounts for 5%-15% of the total volume of the corrosive agent; the concentration of the nitric acid is 65-68%, and the volume of the nitric acid accounts for 1-5% of the total volume of the corrosive agent; the addition amount of the copper chloride is 1-5g per liter of the corrosive agent; the volume of the fatty alcohol-polyoxyethylene ether accounts for 0.5%-2% of the total volume of the corrosive agent; the balance is absolute ethyl alcohol. According to the corrosive provided by the invention, through the synergistic effect of hydrochloric acid, nitric acid, copper chloride and penetrant, the tempered sorbite structure of quenched and tempered steel can be selectively corroded, and particularly, the original austenite grain boundary is preferentially corroded. The method has the advantages of high safety, avoidance of the use of dangerous chemicals, simple and efficient operation, low cost, good corrosion uniformity, stable and reliable result, definite applicability and strong pertinence.

The invention provides a method for recovering metal elements in smoke dust of a rotary hearth furnace, and relates to the technical field of comprehensive recovery of metals. The recovery method comprises the following steps: carrying out water leaching treatment and purification treatment on smoke dust of the rotary hearth furnace to obtain a potassium-sodium solution and a zinc-rich precipitate; the water leaching residues are subjected to first-time acid leaching treatment and second-time acid leaching treatment, and acid leaching liquid and acid leaching residues are obtained; ferric iron in the acid leaching solution is reduced into ferrous iron; and adjusting the pH value to precipitate and separate out bismuth, indium and germanium. According to the recovery method, through selective leaching, two-stage deep extraction and ingenious internal material circulation, efficient recovery of main metal such as potassium, sodium, zinc and lead is achieved, high-value scattered rare metal such as indium, germanium and bismuth is more successfully and comprehensively recovered, and comprehensive utilization of smoke dust resources of the rotary hearth furnace is achieved to the maximum extent.

The application discloses a preparation process and application of a polyamine-based EDTA leaching agent for lead removal from copper anode slime. A chelating system containing strong coordination groups of -NH-, -COOH and -SO3- is formed by the synergic complexing of EDTA-2Na after the double modification of carboxymethylation and sulfomethylation of a polyamine skeleton as a mother nucleus. The leaching agent is used for selective leaching of lead in copper anode slime, and under the conditions of a solid-liquid ratio of 1:10-20, 45-60 DEG C, and pH 5.5-7.0, the lead leaching rate is stably above 94.8%, and the silver retention rate is above 99.9%. The leaching agent is regenerated by lead precipitation with sodium carbonate, and the lead leaching rate is kept above 92.1% after 10 cycles. The process is mild and environmentally friendly, and the equipment is simple, and is suitable for industrial production.

A method for reducing copper from Cu(II) to Cu(I) comprises the step of reacting an Fe(II) reducing agent with Cu(II) in basic conditions. The method may be carried out in basic solution, for example ammoniacal solution. The method has particularly utility in the context of solutions which have been produced by the selective leaching of copper over other metals from elemental copper-containing mixtures into basic lixiviants and, in particular, into ammoniacal lixiviants.

The present application relates to the technical field of waste metal recycling, and specifically provides a selective leaching method for copper in waste circuit boards, comprising the following steps: mixing pretreated waste circuit board raw materials with a methyl sulfonic acid solution, setting a first reaction temperature and adding a strong oxidizing agent and a metal inhibitor for reaction, continuing the reaction at a second reaction temperature after the reaction is completed, and separating to obtain a copper-rich leaching solution and a leaching residue. The present application realizes efficient and selective leaching of copper by precisely controlling the leaching system, so that the target metal enters the solution phase, and other impurity metals are enriched in the leaching residue in the form of precipitation.

The application provides a recovery method and application of nickel, cobalt and lithium in iron-aluminum waste, and the recovery method comprises the following steps: roasting the waste, and performing selective leaching on the roasting product to realize separation of iron and aluminum; performing value separation on the leaching solution to obtain a lithium-containing solution; performing dissolution on the leaching residue, and performing complexation and selective precipitation on the leaching residue by using an ammonia buffer to obtain iron mud and a nickel-cobalt-manganese solution, so that nickel, cobalt and manganese are recovered. The method provided by the application separates and purifies iron-aluminum solid waste, realizes separation of iron and aluminum, ensures enrichment and recovery of nickel, cobalt and manganese, reduces adverse effects on the environment, avoids resource waste, and meets the strategy of green development.

The present disclosure discloses a wet process for recovering valuable metals from a lithium battery. In the method, a waste lithium battery powder is subjected to selective leaching under the condition that a hydrogen sulfide gas is introduced through pressurization, such that Mn2+, Li+, and Al3+ metal ions enter a first-stage leaching liquor and nickel, cobalt, copper, and iron exist in a first-stage leaching residue in the form of a sulfide; then a pH of the first-stage leaching liquor is adjusted to remove aluminum and manganese, which achieves extremely thorough metal separation and leads to relatively pure products; a first-stage leaching residue is subjected to leaching in an acid liquor under a negative pressure, such that the sulfides of nickel, cobalt, iron, and copper are dissolved in a second-stage leaching liquor, and a hydrogen sulfide gas produced can be recycled in the first-stage leaching procedure through pressurization.

This invention discloses an ultrasonic-enhanced selective leaching method for the resource utilization of zinc-containing baghouse dust, belonging to the field of metallurgical dust and sludge comprehensive utilization technology. The method involves low-temperature calcination to activate the zinc-iron spinel structure, combined with a weakly acidic leachate for selective leaching of zinc under mild conditions, further enhanced by ultrasonic-enhanced mass transfer, significantly improving the leaching rate and selectivity of zinc. The leachate is purified to obtain nano-zinc oxide, and the leaching residue is co-sintered with high-silicon iron tailings to form glass-ceramic materials. This invention achieves efficient zinc recovery and full-component resource utilization of the residue, avoiding the use of strong acids and the problem of iron co-dissolution. It achieves high-value comprehensive utilization of valuable metals such as zinc and iron in baghouse dust under low-energy consumption and low-pollution conditions.

This invention discloses a dual-functional material based on steel slag, its preparation method, and its application, belonging to the field of solid waste resource utilization and environmental pollution control technology. The method uses steel slag, a solid waste from the iron and steel industry, as raw material, and prepares an iron-rich catalyst and a calcium-rich adsorbent through selective leaching. The iron-rich catalyst efficiently activates PMS in a photocatalytic persulfate (PMS) system to degrade tetracycline antibiotics in water; simultaneously, the calcium-rich adsorbent can capture CO2 generated during antibiotic degradation in situ, thus achieving multiple objectives of solid waste resource utilization and pollution and carbon reduction. This invention utilizes widely available and inexpensive raw materials and employs a simple process, effectively improving the high-value-added resource utilization level of steel slag and overcoming the carbon emission problems associated with traditional advanced oxidation technologies, providing a new approach for synergistic technologies of wastewater treatment and carbon reduction.

The utility model relates to a system for efficiently recovering gold, silver and copper from complex gold ore gold extraction tailing broken carbon, which comprises a ball mill, and an ore pulp pump and a grading cyclone which are sequentially connected with the ball mill, and an overflow port of the grading cyclone is sequentially connected with a medicament stirring barrel, a flotation system and a 1 # filter; a filter residue opening of the 1 # filter is sequentially connected with a novel ashing roasting furnace, a reduction smelting furnace, a copper-silver leaching stirring tank and a 2 # filter, a filtrate opening of the 2 # filter is sequentially connected with a silver chloride precipitation stirring tank and a 3 # filter, a filtrate opening of the 3 # filter is sequentially connected with a copper replacement stirring tank and a 4 # filter, and a filter residue opening of the 3 # filter is sequentially connected with a silver replacement stirring tank and a 5 # filter. Flotation equipment, ashing roasting equipment, reduction smelting equipment, selective leaching equipment and the like are ingeniously combined to form a complete complex gold ore gold extraction tailing broken carbon recovery system, and meanwhile, proper technological parameters are matched, so that high-efficiency recovery of valuable metals such as gold, silver and copper in complex broken carbon with high copper, high iron, high calcium and the like is achieved.

The application discloses a method for analyzing phases of iron in ores, and belongs to the technical field of mineral analysis. The method comprises the following steps: after magnetic separation of an ore sample, performing iron valence state analysis on a magnetic product, and distinguishing a magnetic iron phase, a pseudo hematite phase and a magnetic intergrowth phase based on the deviation degree of the ratio of divalent iron to trivalent iron from the theoretical ratio of magnetite; sequentially performing iron carbonate phase selective leaching-oxidation post-treatment, hematite-limonite phase reduction-inhibition synergistic selective dissolution, iron sulfide phase liquid phase complexation-solid phase charring step-by-step extraction and iron silicate phase alkali fusion digestion on a non-magnetic product; and finally, performing plasma atomic emission spectrometry on each phase to-be-measured solution and total iron digestion liquid, and calculating the iron content of each phase. The application solves the key problems in traditional iron phase analysis, such as incomplete classification of magnetic iron, poor selectivity of non-magnetic phase and insufficient wide use.

The invention relates to the technical field of separation and recovery of selenium and tellurium, in particular to a method for separating and recovering selenium and tellurium from alloy smoke dust. The method comprises the following steps: firstly, mixing alloy smoke dust of a smelting furnace with a sulfuric acid solution to obtain a first-section leaching solution and a first-section leaching residue; mixing the first-stage leaching residues with a selective leaching agent, and controlling the oxidation potential to obtain a second-stage leaching solution and second-stage leaching residues; then mixing the second-stage leachate with a reduction precipitator to obtain crude selenium; and mixing the second-section leaching residues with an alkali solution to obtain a third-section leaching solution and third-section leaching residues, adding concentrated acid into the third-section leaching solution, controlling the pH value, and performing solid-liquid separation after hydrolysis to obtain tellurium dioxide. According to the method, the problems of low separation efficiency and high cost of low-grade and near-content selenium and tellurium smoke dust in a traditional process are solved in one-step leaching, the purity of crude selenium and tellurium dioxide is improved by controlling process conditions, and the method is short in process flow, high in selective separation efficiency, high in comprehensive resource recovery rate and outstanding in environmental protection property and economical efficiency.

The present invention discloses methods for the selective recovery of precious metals from electronic waste (e-waste). An environmentally friendly oxidizing agent is developed for the selective oxidation and separation of copper from printed circuit board (PCB) metal powder. Additionally, selective recovery of gold and silver is achieved using fluxing agents. Following selective leaching, copper is recovered from the leach solution through cementation with more active metal species. Impurities, such as aluminum (Al) and iron (Fe), are subsequently removed via pH precipitation. The remaining leached elements are further separated using crystallization or additional pH precipitation processes.

The invention relates to the technical field of composite copper foil recovery, in particular to a method for recovering copper and PET (polyethylene terephthalate) from waste PET copper foil step by step, which comprises the following steps: 1) obtaining the waste PET copper foil; (2) the waste PET copper foil obtained in the step (1) is immersed in a leaching treatment solution containing H2SO4, CuSO4 and NaCl, and a leaching solution containing copper and a PET base material are obtained; 3) recovering copper from the leachate by adopting an electrochemical deposition method, and obtaining a copper deposit; 4) respectively pretreating a cross-linking agent DGEBA (bisphenol A diglycidyl ether), a catalyst Zn (acac) 2 (zinc acetylacetonate) and the PET base material separated in the step 2), and then mixing to obtain a mixed material; 5, PET is recycled from the mixed material in the step 4 through a Vitrimers chemical modification method.According to the method, the integrated process of selective leaching-electrodeposition cooperating with copper recycling and Vitrimers chemical modification PET regeneration is adopted, the treatment cost is low, the requirements for environmental protection and sustainable development are met, and it is possible that PET copper foil is efficiently recycled in an environment-friendly mode.

The invention relates to the technical field of hydrometallurgy, and provides a cobalt nickel hydroxide leaching and purifying method which comprises the following steps: preparing acidic ore pulp and alkaline ore pulp; concentrated sulfuric acid is added into the acidic ore pulp for high-acid leaching, and a silicon-manganese product and high-acid leaching liquid are obtained after solid-liquid separation; neutralizing the high-acid leaching solution by adopting alkaline ore pulp, and carrying out solid-liquid separation to obtain a nickel-cobalt sulfate solution and neutralized slag; curing the neutralized slag by adopting concentrated sulfuric acid, and carrying out solid-liquid separation to obtain a silicon-manganese product and a cured solution; carrying out iron and aluminum removal on the cured liquid by adopting alkaline ore pulp and alkaline substances, and carrying out solid-liquid separation to obtain iron and aluminum slag and iron and aluminum removed liquid; and an alkaline substance is adopted for impurity removal of the iron and aluminum removed liquid, and after solid-liquid separation, a crude nickel enriched product and an impurity removed liquid are obtained. By means of the method, the problems that in the prior art, process investment is large, acid and alkali consumption is large, and selective leaching of valuable metal and effective open circuit of impurity elements cannot be achieved can be solved.

The invention relates to the technical field of non-ferrous metal hydrometallurgy, and discloses a multi-component tin waste precise purification and regeneration process which comprises the following steps: preparing a ternary deep eutectic solvent composed of choline chloride, an acidic hydrogen bond donor and an activating auxiliary agent; the solvent is used for carrying out catalytic activation dissolution on the multi-component tin waste, and selective leaching of tin is achieved; the obtained leachate is electrolyzed in a composite electrodeposition mode combining dynamic potential gradient scanning and pulse current, and high-purity metallic tin is obtained at a cathode; carrying out vacuum distillation on the electrolyzed waste liquid, separating and recovering valuable metal byproducts, and simultaneously obtaining a regenerated deep eutectic solvent; and returning the regenerated solvent to the dissolving step for recycling. Through the synergistic effect of the specific solvent and the composite electrolysis mode, the purity of the regenerated tin is remarkably improved, the solvent can be recycled, the process is green and environmentally friendly, and the cost is low.

The invention discloses a preparation method of a multistage porous NiCoAl hydroxide electrocatalyst pole piece for a lithium-carbon dioxide battery positive electrode. Selective corrosion of Al in the Ni-Co-Al precursor alloy is regulated and controlled through a dealloying technology, and the NiCoAl hydroxide electrocatalyst with multilevel channels and a large number of nanometer interfaces is successfully constructed. The metal elements such as cobalt and nickel are compounded to construct a rich interface, so that the atom coordination environment, chemical bonding mode, electronic configuration and the like of the metal elements such as cobalt and nickel can be obviously changed, and the intrinsic activity of the catalyst is improved, thereby changing the adsorption of reactants, products and intermediate species in CO2 reduction and precipitation reaction. In addition, the spongy porous structure has open and communicated pore channels, a large specific surface area and a continuous conductive skeleton, mass transfer, electron conduction and discharge product deposition are facilitated, and the apparent dynamics of the catalyst is improved. Besides, the preparation process of the catalyst has remarkable advantages, the operation process is simple and clear, the development cost is low, large-scale preparation can be realized, the porous structure can be accurately regulated and controlled, the reproducibility of experimental results is excellent, and a solid foundation is laid for large-scale popularization and application.

The invention discloses a copper-chromium alloy waste recovery method which comprises the following steps: carrying out hydrogenation-disproportionation treatment on copper-chromium alloy waste, crushing, screening, and respectively collecting a copper-rich phase and a chromium-rich hydride phase; leaching the copper-rich phase in a weak acid solution, carrying out solid-liquid separation, collecting solids, and carrying out dehydrogenation to obtain copper; and uniformly mixing the chromium-rich hydride phase with water, adding a precipitant to carry out precipitation reaction, collecting the precipitate, and carrying out reduction treatment to obtain chromium. According to the method, a hydrogenation-disproportionation-selective leaching technical route is adopted, efficient cleaning separation of copper and chromium is achieved, strong acid and strong base are not needed in the whole process, the metal recovery rate is high, the product purity is high, and the method is suitable for industrial production.