212results about "Manganese sulfates" patented technology

The invention discloses a method for preparing high-purity manganese sulfate and co-producing manganese dioxide for a battery by reducing manganese oxide ore with sulfur dioxide, metal smelting SO2-containing flue gas or sulfur acid-making industry SO2 gas is used as a reducing agent, discharged tail gas after absorption can be as low as 30 mg / m < 3 > or below, and the leaching rate of manganese element can reach 98% or above. By adopting the technical scheme of the process, the comprehensive recovery rate of manganese is easy to achieve more than 95%, and two high-value products of high-purity MnSO4 and MnO2 for batteries are produced; s2O6 < 2-> is decomposed and removed in the same reaction kettle by adopting a high-temperature oxidation process to obtain a manganese sulfate solution and co-produce a high-quality MnO2 product suitable for batteries; a speed-controlled crystallization method is adopted for high-temperature crystallization, the one-time crystallization separation and purification rate of impurity ions such as magnesium, calcium, potassium and sodium is stably increased from 70-80% to 90% or above, and the purpose of obtaining a battery-grade high-purity manganese sulfate product through two times of recrystallization is achieved.

The invention discloses a method for recovering and separating nickel, cobalt and manganese from waste ternary lithium ion battery material lithium extraction slag, which comprises the following steps: pulping waste ternary battery material lithium extraction slag, leaching, introducing compressed air as an oxidant, and carrying out solid-liquid separation after leaching to obtain a leachate and leaching slag; sequentially performing copper removal, iron removal, aluminum removal and fluorine removal on the leachate to finally obtain fluorine-removed liquid; carrying out refined filtration on the fluorine-removed liquid to obtain a refined-filtered liquid; adjusting the pH value of the finely filtered liquid, and extracting impurities by using nickel soap P204 to obtain a rich organic phase and raffinate 1; extracting manganese from the raffinate 1 by using nickel soap P204 to obtain a manganese-rich organic phase and raffinate 2; extracting cobalt from the raffinate 2 by using nickel soap P507 to obtain a cobalt-rich organic phase and raffinate 3; and carrying out evaporative crystallization on the raffinate 3 to obtain nickel sulfate. The whole process has the advantages of short flow, high metal recovery rate, high product quality and low sodium-containing wastewater treatment capacity, and nickel, cobalt, manganese and lithium elements in the waste ternary lithium ion battery material are efficiently recycled by combining a front-end lithium extraction and recovery process, so that resource circulation is realized.

A treatment process for crystallizing a metal sulfate involving pre-treating a feedstock comprising calcium, magnesium, and / or lithium impurities, the pre-treating involving pre-leaching the feedstock in the presence of a lixiviant, selectively extracting a first portion of any of the impurities from the feedstock, and forming a leached solution comprising an uncrystallized metal sulfate and any remaining impurities; and / or refining the leached solution and removing a second portion of any of the remaining impurities; and crystallizing the uncrystallized metal sulfate from the leached solution to form a crystallized metal sulfate. So processed, the crystallized metal sulfate may be battery-grade or electroplating-grade.

The invention belongs to the field of lithium recovery, and particularly relates to a method and a system for electrochemically recovering lithium ions in ternary lithium battery leachate. The method comprises the following steps: (1) leaching the cathode material of the waste ternary battery to obtain a ternary leachate; (2) performing lithium ion enrichment in a capacitive deionization device by taking the ternary leaching solution obtained in the step (1) as a lithium source to obtain a lithium-rich receiving solution and a lithium-removed recycling solution; (3) recovering the lithium-rich receiving liquid to obtain recovered lithium; and performing non-lithium metal element recovery on the lithium-removed recovery liquid. According to the technical scheme, the rocking chair type capacitive deionization RCDI system adopts a waste ternary battery cathode material (SNCM) as an electrode material, the extraction quantity of a single reaction cycle can reach 4.90 mM g <-1 >, continuous and selective lithium extraction is realized, and meanwhile, the cost and the environmental influence are reduced.

The invention provides a method for preparing high-purity manganese sulfate by taking pyrolusite and pyrite as raw materials, which comprises the following steps: carrying out reduction reaction on the pyrolusite and the pyrite by adopting acid leaching to obtain a manganese sulfate solution, and continuously feeding the pyrolusite until ferrous ions in the system are completely oxidized into iron ions; adding a pH regulator to remove iron, adding a vulcanizing agent to remove heavy metals, adding a pH regulator to remove silicon and aluminum, and carrying out solid-liquid separation to obtain a manganese sulfate solution containing calcium and magnesium; adding a fluorinating agent into the manganese sulfate solution containing calcium and magnesium to remove calcium and magnesium, and carrying out solid-liquid separation to obtain a fluorine-containing high-purity manganese sulfate solution; and extracting the fluorine-containing high-purity manganese sulfate solution to obtain a fluorine-containing organic phase and battery-grade high-purity manganese sulfate. According to the method, the medicament cost in the removal process is greatly reduced, namely, the raw material pyrolusite is used for replacing an external oxidant to oxidize Fe < 2 + > in a system, and a large amount of jarosite and sodium jarosite are generated in situ, so that complete removal of potassium, sodium and iron is realized.

The invention belongs to the technical field of waste battery recovery and regeneration, and particularly relates to a method for recovering valuable metal from a waste lithium battery positive electrode material. The method comprises the following steps: carrying out sulfuration roasting on waste positive electrode powder, selectively extracting lithium in a water leaching manner, and precipitating lithium to obtain lithium carbonate; separating and purifying the nickel, the cobalt and the manganese through microwave acid leaching, precipitation impurity removal and step-by-step extraction to obtain extract liquor of the nickel, the cobalt and the manganese, and performing reverse extraction on the extract liquor to obtain battery-grade cobalt sulfate, battery-grade nickel sulfate and battery-grade manganese sulfate. According to the method, lithium is extracted firstly, the influence of the lithium element on subsequent nickel-cobalt-manganese extraction is reduced, meanwhile, the recovery rate of lithium is increased through the water leaching method, and the recovery cost is reduced. According to the method, precipitation and impurity removal are performed before nickel-cobalt-manganese extraction, so that the content of impurities in a sulfate solution is reduced, and the recovery rate of nickel, cobalt and manganese is greatly improved.

The utility model discloses a production line for preparing manganese sulfate from zinc smelting manganese-containing slag, the production line for preparing manganese sulfate from zinc smelting manganese-containing slag comprises an autoclave evaporator and at least one reaction tank, the autoclave is provided with a gas inlet and a gas outlet opposite to the gas inlet, the autoclave is suitable for accommodating a zinc anode slime mixture, the gas inlet is suitable for introducing reducing gas, and the gas outlet is suitable for introducing reducing gas; carrying out reduction leaching reaction with a zinc anode mud mixture; the reaction tank is positioned at the downstream of the high-pressure kettle and is used for performing impurity removal treatment on a solution flowing into the reaction tank; and the evaporator is positioned at the downstream of the reaction tank and is suitable for evaporating, crystallizing and drying the solution flowing into the evaporator. Therefore, through the cooperation of the autoclave, the reaction tank and the evaporator, a continuous production line for reduction leaching, purification and impurity removal, evaporative crystallization and drying is formed, the high value of manganese ions and the recycling of the zinc smelting manganese-containing slag can be optimized, the technological process and the production cost can be saved, and the production line is high in applicability and universality, environmentally friendly and capable of saving energy.

The invention discloses a method for preparing a manganese sulfate crystal by using manganese carbonate ore. The preparation method of the manganese sulfate crystal comprises the following steps: leaching manganese carbonate ore by using sulfuric acid to obtain a leaching solution, precipitating the leaching solution by using a heavy removing agent to remove heavy metal ions, neutralizing redundant sulfuric acid in the leaching solution, introducing a precipitating agent, reacting with the precipitating agent to obtain a precipitate, washing the precipitate with water to remove impurities, and dissolving by using sulfuric acid to obtain the manganese sulfate crystal. And after dissolving, precipitating a small amount of residual calcium and magnesium ions by using fluoride, filtering to obtain fluorine-containing manganese sulfate filtrate, finally adding a fluorine removal agent for solid-liquid separation, and evaporating and crystallizing the filtrate to obtain manganese sulfate crystals. The manganese sulfate crystal is suitable for production of a lithium ion battery positive electrode material. According to the preparation method of the manganese sulfate crystal, the impurity removal cost is greatly reduced. The invention also discloses a method for preparing manganous-manganic oxide from manganese carbonate ore. The tap density of the manganous-manganic oxide is greater than 2.3 g / cm < 3 >, the specific surface area is less than 3m < 2 > / g, and the requirement of a battery-grade material is met.

The present application relates to electrolytic manganese technology field, specifically to a kind of method for removing heavy metal ions in manganese sulfate solution.The method for removing heavy metal ions in manganese sulfate solution provided by the present application includes the following steps: adding oxidizing agent to pretreated manganese sulfate solution, mixing and stirring, then adjusting the pH value of solution to 5.5-6.0, filtering, to obtain the first purified manganese sulfate solution;Add sulfidation agent to the first purified manganese sulfate solution, filter, to obtain the second purified manganese sulfate solution;Add porous resin polymer to the second purified manganese sulfate solution, add the mixed solution into a sealed container, introduce nitrogen, make the pressure in the sealed container reach 1.1-1.5MPa and maintain for 2-10min, then open the air valve and release pressure instantaneously, stand, filter, fine filter, to obtain the purified manganese sulfate solution.The method provided by the present application can not only effectively remove heavy metal ions in solution, but also effectively reduce the COD value of the purified solution, reduce the loss of manganese content in solution.

The invention provides a manganese sulfate purification method based on a membrane separation technology, and relates to the technical field of manganese sulfate purification, the manganese sulfate purification method comprises the following steps: S1, pretreatment and solution blending: starting a stirring tank for stirring at a stirring speed of 230-500 RPM; adding a raw material solution into the stirring tank; adding a mixed solvent into the raw material solution, wherein the total adding amount of the mixed solvent accounts for 1-2% of the mass of the raw material solution; according to the preparation method, a mixed solvent and a stability additive are introduced in the raw material solution preparation stage, and the stirring speed and the reaction temperature are regulated and controlled, so that the uniformity and the system stability of raw material components are enhanced, the solubility and the dispersity of impurity components are reduced, and subsequent impurities are promoted to be thoroughly and sufficiently settled; in the chemical precipitation stage, precipitation of the impurities is accelerated by controlling the proportion of a precipitator, the reaction temperature and the stirring speed, so that the precipitation rate and the particle size uniformity of precipitated particles are improved, and the impurities are fully separated from a main solution.

The invention provides a method for recycling battery-grade manganese sulfate from manganese-containing feed liquid. The method comprises the following steps: (1) carrying out resin adsorption on a manganese-containing feed liquid to obtain a nickel-cobalt adsorbate and an adsorbed feed liquid; (2) sequentially carrying out extraction treatment and reverse extraction treatment on the adsorbed feed liquid to obtain a solution containing manganese sulfate and an organic phase after reverse extraction; (3) carrying out evaporative crystallization on the solution containing manganese sulfate to obtain battery-grade manganese sulfate; positive ions in the manganese-containing feed liquid comprise manganese ions, nickel ions, cobalt ions, calcium ions and magnesium ions, and negative ions in the manganese-containing feed liquid comprise sulfate ions; an extraction agent adopted in the extraction treatment process comprises an HBL116 extraction agent. According to the method disclosed by the invention, metal oxidation hydrolysis cannot be caused to generate a third phase, the extraction process is stable, enrichment of a high-concentration manganese sulfate solution is realized, high-purity manganese sulfate crystals with qualified impurities are obtained, and efficient recovery of manganese in a high-calcium-magnesium feed liquid system can be realized; and a complicated recovery process is not needed, so that the cost is lower.

The present disclosure provides a method of recovering a spent battery cathode material comprising lithium and at least one of nickel, cobalt and / or manganese, the method comprising: heating the spent battery cathode material in a reducing atmosphere to form a heat-treated spent battery cathode material comprising LiF and one or more of LijO, LiOH and LijCOs; washing the heat treated waste battery cathode material in an aqueous solvent to extract lithium-containing species and fluorine-containing species wherein the aqueous solvent is free of alkaline earth metal hydroxides or other species intended to reduce or prevent soluble fluorine species from remaining dissolved in the aqueous solvent; separating an aqueous solvent comprising lithium and fluorine species from the heat treated waste battery material; after separating an aqueous solvent comprising lithium and fluorine species from the heat-treated waste battery material, treating the aqueous solvent to separate lithium species from fluorine species; recycling a lithium substance in the form of lithium hydroxide or lithium carbonate; forming an acidic aqueous recovery feed comprising one or more of nickel, cobalt and / or manganese by leaching the heat treated waste battery cathode material with a mineral acid after the step of separating the aqueous solvent from the heat treated waste battery material; and recovering one or more of nickel, cobalt and / or manganese from the acidic aqueous recovery feed by a further process step selected from one or more of solvent extraction, solid phase extraction, electrochemical extraction and precipitation processes.

A waste battery processing method includes a discharging process of discharging a waste battery, a dismantling process of dismantling the discharged waste battery into battery cell units, a shredding process of shredding the dismantled waste battery, a roasting process of roasting the shredded waste battery, a pulverizing process of pulverizing the fired waste battery, and a hydrometallurgical process of extracting and recovering metals from the pulverized waste battery.

The invention belongs to the technical field of waste battery recovery, and particularly relates to a short-process method for recovering battery-grade lithium carbonate and valuable metals from waste ternary lithium battery black powder. According to the method, a lithium closed-loop technical system of blank roasting, cyclic leaching, synergistic impurity removal, lithium phosphate aluminum removal, directional extraction and split-flow extraction of lithium, nickel and magnesium and seed crystal induction parallel flow lithium precipitation is constructed, a roasting aid, a reducing agent and an aluminum removal agent do not need to be added in the whole process, and the redundant processes of traditional lithium carbonate purification such as carbonization, resin purification and pyrolysis are omitted; the lithium liquid concentration cost is saved, no hazardous waste exists, green and clean production is achieved, and the quality of battery-grade products is guaranteed through collaborative impurity removal and directional extraction.

The invention discloses a green continuous production process of electrolytic manganese dioxide, which comprises the following steps: mixing a manganese-containing raw material and sulfuric acid according to a mass ratio of 1: (1.2-1.5), and then carrying out acid leaching at 80-90 DEG C for 2-3 hours to improve the manganese leaching rate to 91-98%; 10-15% hydrogen peroxide oxidation is combined with accurate regulation and control and flocculent precipitation of pH 5-6, so that the iron impurity residue is less than or equal to 5 ppm; in the electrolysis process, sulfuric acid is continuously supplemented to maintain the concentration of 150-180 g / L, the titanium-based lead dioxide anode and the stainless steel cathode are matched, and the current efficiency is 88-91.5%; and carrying out three-stage countercurrent washing and drying at 120-130 DEG C on the product to obtain the electrolytic manganese dioxide with the purity of more than or equal to 93%. The process provided by the invention is suitable for resource utilization of low-grade pyrolusite, and the obtained product is mainly used in the fields of lithium-manganese battery positive electrode materials, magnetic materials and catalyst carriers.

Water is added into manganese dioxide powder to prepare manganese slurry, ammonia water or ammonium bicarbonate is used for adjusting the pH value, sulfur-containing flue gas enters a desulfurizing tower to react with the manganese dioxide mineral powder and the manganese slurry to remove sulfur dioxide, manganese sulfate slurry is generated and can be used for obtaining high-purity manganese sulfate, and ammonium sulfate generated through the reaction can be recycled. The process is mild in production condition, SO2 in the flue gas is converted into available manganese sulfate, resource recycling of sulfur dioxide in the flue gas can be achieved, economic benefits are generated, meanwhile, environmental pollution is reduced, and a technical route is provided for sulfur-containing flue gas treatment and resource utilization. The produced manganese sulfate can be used for preparing high-quality battery-grade manganese sulfate, a raw material is provided for the new energy battery industry, and the market competitiveness of enterprises is improved. The process method provided by the invention accords with the concept of combining ecological environment protection and economic development, and has a relatively high application value.

A method of preparing a cathode active material composition involves combining a first cathode active material including recycled lithium 40 with a second cathode active material 41; wherein the ratio

The invention discloses a method for preparing manganese sulfate by treating alkylated waste sulfuric acid through an oxidative degradation-adsorption method, and belongs to the technical field of industrial waste recycling. The method comprises the following steps: by taking pyrolusite as an oxidizing agent, efficiently oxidizing and degrading organic matters in the waste sulfuric acid in an acidic medium of alkylated waste sulfuric acid, and synchronously reducing and leaching manganese; according to the method, pyrite reduction leaching and H2O2 oxidative degradation (assisted by iron ion catalysis) are combined with activated carbon adsorption to deeply treat organic matters in a solution, and finally, high-purity manganese sulfate is prepared through impurity removal and crystallization. According to the method, harmlessness and recycling of the alkylated waste sulfuric acid are achieved, the process cost is low, secondary pollution is avoided, the purity of the manganese sulfate product reaches the industrial grade, and the method can be widely applied to the fields of batteries, fertilizers and the like and has remarkable environmental and economic benefits.

The invention discloses a device for preparing battery-grade high-purity manganese sulfate by absorbing sulfur dioxide through manganese carbonate ore, and belongs to the technical field of manganese sulfate preparation. Flue gas containing sulfur dioxide is introduced into an air cavity in a desulfurization tower through a gas inlet pipeline, so that manganese carbonate slurry can be in contact with the flue gas containing sulfur dioxide and absorb sulfur dioxide; a mixing paddle in the driving assembly rotates and stirs manganese carbonate slurry, the fluidity of the manganese carbonate slurry in the material supporting assembly is improved by matching with the guiding and conveying effect of a spiral blade on the manganese carbonate slurry, gas can overflow from a flow dividing hole in a material supporting frame after rising, a pump body works to enable a feeding pipe to extract the manganese carbonate slurry from the material supporting frame, and therefore the manganese carbonate slurry is pumped out of the material supporting frame. The manganese carbonate slurry falls on the material supporting frame through the discharging pipe and can be in contact with the rising gas again, so that the adsorption effect of the manganese carbonate slurry is improved in a multi-stage absorption mode, the adsorption capacity of manganese carbonate is fully exerted, and subsequent efficient preparation work of high-purity manganese sulfate is facilitated.

The invention relates to the field of resource utilization of industrial solid wastes, in particular to a method for preparing battery-grade manganese sulfate by purifying industrial solid wastes, which comprises the following steps: by taking silicomanganese metallurgical fly ash as a raw material, grinding, alkaline leaching, heating reaction and centrifugal separation to obtain manganese-containing filter residues; and the battery-grade manganese sulfate is prepared through the steps of sulfuric acid neutralization, filter pressing, oxalic acid-manganese monoxide refining, evaporative crystallization and the like. According to the method, all-component high-value utilization of elements such as manganese, silicon and potassium in the fly ash is achieved, the raw material recovery rate reaches 99.7% or above, the purity of the prepared manganese sulfate is larger than or equal to 99.5%, meanwhile, by-products such as potassium sulfate, sodium chloride, aluminum hydroxide and sludge containing 80% of silicon dioxide are produced, and remarkable economic benefits and ecological benefits are achieved.

A treatment process for crystallizing a metal sulfate involving pre-treating a feedstock comprising calcium, magnesium, and / or lithium impurities, the pre-treating involving pre-leaching the feedstock in the presence of a lixiviant, selectively extracting a first portion of any of the impurities from the feedstock, and forming a leached solution comprising an uncrystallized metal sulfate and any remaining impurities; and / or refining the leached solution and removing a second portion of any of the remaining impurities; and crystallizing the uncrystallized metal sulfate from the leached solution to form a crystallized metal sulfate. So processed, the crystallized metal sulfate may be battery-grade or electroplating-grade.

The invention discloses a method for dissolving and purifying a manganese dioxide-containing mineral. The method comprises the following steps: crushing and grading the manganese dioxide mineral for later use; washing the graded material with dilute sulphuric acid, and then centrifugally filtering to obtain filter residues and filtrate; preparing filter residues into a solid solution with water, adding concentrated sulfuric acid and methyl sulfate for primary dissolution, and filtering to obtain lead-containing minerals and filtrate; and after excessive manganese ore is added into the filtrate, MnCO3 and H2O2 are added, manganese ore which is not completely reacted and obtained through filtering is dissolved again, ammonia water is added into the filtrate for impurity removal, and a MnSO4 solution is obtained. According to the method, manganese dioxide-containing minerals are crushed to obtain particles, the particles are prepared into a solid material solution for secondary reduction acid leaching, the contact area of the mineral particles and reducing agents such as methyl sulfate, methanol and hydrogen peroxide is greatly increased, and methyl sulfate is used as the reducing agent, so that the method has the advantages of high reaction rate, high efficiency, safer storage and transportation and the like; the extraction rate of manganese ions is improved, and the extraction time is shortened.

The invention relates to a comprehensive recovery method of acid waste liquid in a process of producing graphene oxide by a chemical method. The method comprises the following steps: filtering the acid waste liquid to remove impurities; the method comprises the following steps: introducing ammonia gas into the acidic waste liquid, controlling the adding amount of the ammonia gas, enabling the reaction temperature to be within a proper range by virtue of reaction heat generated in a reaction process, and enabling a reaction system to be still acidic, so that part of SO4 < 2-> ions in the acidic waste liquid react with NH3 to generate (NH4) 2SO4, and the residual SO4 < 2-> is combined with Mn < 2 + > ions to form a MnSO4 supersaturated solution which is completely separated out in a salt form; filtering while the solution is hot to obtain a MnSO4 crystal substance and a potassium ammonium sulfate solution; introducing ammonia gas into the ammonium potassium sulfate solution to obtain a mixed solution; and carrying out reduced pressure distillation on the mixed solution to obtain a solid which is the ammonium potassium sulfate compound. The method has the beneficial effects that the resource utilization benefit of each element in the acid waste liquid is maximized, and the production cost of ammonium sulfate potassium compound fertilizer and graphene oxide is reduced.

The invention provides a preparation system and process for high-purity manganese sulfate, and relates to the technical field of high-purity manganese sulfate preparation. The pushing assembly is mounted in the extracting assembly; the manganese ore collecting assembly is mounted on the left side of the extracting assembly; a discharge through groove is formed in the left side of the rectangular extraction frame; a liquid discharge pipe is fixedly mounted on the front side of the rectangular extraction frame; a manganese ore collecting box is fixedly mounted at the tops of two stable guide shafts, the right side of the manganese ore collecting box is in contact with a rectangular extraction frame, and the manganese ore collecting box is located on the left side of a discharging through groove; according to the device, the effect of collecting extracted manganese ore is achieved, and the effect of sealing the discharge through groove is achieved, so that the discharge through groove can be opened only when the manganese ore is discharged, and liquid is prevented from flowing out; the problem that when separated manganese ore is discharged, a worker needs to open a baffle, and otherwise, part of liquid can flow out through a discharging opening is solved.

A method for producing an aqueous manganese sulfate solution using a sulfur dioxide gas reduction leaching method includes: a raw material preparation process of preparing a manganese-containing by-product containing manganese and impurities; a pulverizing and washing process of pulverizing and washing the manganese-containing by-product; a reduction leaching process of leaching a pulverized manganese-containing by-product obtained by the pulverizing and washing process; a neutralization process of neutralizing a leached liquid produced in the reduction leaching process; a first purification process of purifying a neutralized liquid produced in the neutralization process; and a second purification process of further purifying a first-purified liquid produced in the first purification process. The reduction leaching process is performed using an inorganic acid and a sulfur dioxide gas.

The invention discloses a method for preparing industrial manganese carbonate and high-purity manganese sulfate based on the circulation of ammonium sulfate resources. The invention uses low-grade rhodochrosite powder as raw material, adopts ammonium sulfate roasting and leaching, and the roasting gas is captured to prepare a manganese precipitant; the roasted ore sand is leached by water, and a manganese sulfate mother liquor is prepared after preliminary impurity removal; the manganese sulfate mother liquor is combined with the manganese precipitant for reaction, and the solid phase product is a composite manganese salt, and the liquid phase is evaporated and crystallized to obtain ammonium sulfate powder, which is reused for roasting and leaching; the composite manganese salt is slurried with water, heated and stirred continuously, and air is introduced, and the solid phase is dried after filtering to obtain industrial-grade manganese carbonate, and the liquid phase is evaporated and crystallized to obtain high-purity manganese sulfate. The invention realizes the ammonia-sulfur substance cycle of the manganese-based material preparation process, and effectively reduces the reagent input cost. The invention can simultaneously prepare industrial manganese carbonate and high-purity manganese sulfate, so as to achieve efficient utilization of manganese resources. Compared with the traditional process, it has the characteristics of low cost, simple operation, stable products, etc.

In the recovery method provided in this application, CO is generated by the reaction of oxalic acid and concentrated sulfuric acid. This provides an acidic atmosphere for the reaction between the cathode powder and CO, allowing some of the cathode powder (LiMeO2) to melt, transforming the solid-gas two-phase system into a solid-gas-liquid three-phase system, which is beneficial for improving the recovery rate of Li ions in LiMeO2. Furthermore, the use of CO for pre-lithiation results in a low lithium content in the solid filter material, minimizing interference from lithium ions in impurity removal and providing the possibility for subsequent efficient impurity removal. On the other hand, under acidic conditions, CO undergoes a reduction reaction with the cathode powder, reducing high-valence ions in the cathode powder to lower-valence ions, resulting in a more thorough reduction. This allows the solid filter material to dissolve in sulfuric acid, achieving efficient impurity removal. Additionally, Al is removed by adding alkali, oxidant, fluoride, and adsorbent. 3+ Fe 3+ Ca 2+ Mg 2+ F ‑ A second solution containing MeSO4 is obtained, which can be used as a precursor for preparing positive electrode active materials. It achieves efficient overall impurity removal and improves lithium recovery rate, while obtaining a high-purity MeSO4 solution.

This invention discloses a method for producing sulfate from waste acid wastewater, relating to the field of industrial wastewater reuse technology. The method includes the following steps: raw material pretreatment: collecting waste acid wastewater generated from the washing process of non-ferrous metal smelting flue gas, and concentrating it to obtain concentrated acid water; slurrying and leaching: mixing materials containing metal oxides with the concentrated acid water in a certain proportion, and carrying out slurrying and leaching reactions; purification: purifying the leached solution to obtain a purified solution; sulfate preparation: treating the purified solution to obtain a solid sulfate product. This method directly uses waste acid to replace expensive purchased sulfuric acid, significantly reducing the production cost of sulfate. It is particularly suitable when sulfuric acid market prices are high. Conventionally, producing one ton of zinc sulfate consumes 0.43 tons of sulfuric acid, and producing one ton of manganese sulfate consumes 1.23 tons of sulfuric acid. Using this method, sulfuric acid is directly replaced, resulting in significant cost savings.

The invention provides a method for recycling electrolytic manganese industrial waste salt, which comprises the following steps: mixing the electrolytic manganese industrial waste salt with calcium oxide, and carrying out first heat treatment and second heat treatment to obtain a treated product; the treated product is subjected to water leaching and solid-liquid separation, and first leaching residues and first leaching liquid are obtained; evaporating and crystallizing the first leachate to obtain a magnesium sulfate product; the first leaching residues and ammonium sulfate are mixed and subjected to ball milling, and a mixture is obtained; roasting the mixture to obtain a roasted product; after the roasted product is subjected to water leaching, second leaching residues and second leaching liquid are obtained; evaporating and crystallizing the second leaching solution to obtain a manganese sulfate product; the second leaching residues are subjected to water washing, solid-liquid separation and drying, and industrial gypsum is obtained. The method is simple in technological process, mild in technological condition, low in energy consumption and low in needed cost, the environmental protection pressure of storage of the electrolytic manganese metal industrial waste salt can be eliminated, efficient recycling of Mg, Mn, NH4 < + > / NH3 and S resources in the electrolytic manganese metal industrial waste salt and recycling of Ca can be achieved, and the purity of recycled manganese sulfate reaches the battery grade.

One embodiment of the present invention is a method for producing an aqueous manganese sulfate solution using a sulfur dioxide reduction leaching method, comprising: a raw material preparation step of preparing a manganese-containing by-product containing manganese and impurities; a pulverization step and a washing step of pulverizing and washing the manganese-containing by-product; a reduction leaching step of leaching the manganese-containing by-product pulverized by the pulverization step and the washing step; a neutralization step of neutralizing the post-leaching solution generated by the reduction leaching step; a first purification step of purifying the post-neutralization solution generated by the neutralization step; and a second purification step of additionally purifying the solution after the first purification generated by the first purification step, wherein the reduction leaching step is carried out using an inorganic acid and sulfur dioxide gas, and discloses a method for producing an aqueous manganese sulfate solution using a sulfur dioxide reduction leaching method.