199results about "Iron sulfates" patented technology

The invention relates to the technical field of water treatment agent preparation and environmental governance material processing, in particular to polymeric ferric sulfate and a preparation method thereof.The preparation method comprises the steps that steam condensation recycled water of a thermal power plant of an aluminum factory is mixed with ferrous sulfate and concentrated sulfuric acid to form a reaction solution, oxygen is introduced for an oxidative polymerization reaction, and a liquid intermediate is generated; gradient cooling is carried out on the liquid intermediate to control the molar ratio of ferric ions to hydroxyl, and a porous solid precursor is formed through concentration and closed aging; crushing the precursor, performing graded drying by adopting a rotary kiln and flash drying, and synchronously spraying a hydrophobic modifier to reduce the surface hydroxyl activity; the powdery product is secondarily dried in a nitrogen inert environment, and moisture absorption and agglomeration are inhibited. The invention solves the problems of mixed crystal forms, delayed release of effective components and secondary pollution in the traditional process. The obtained product is uniform in crystal form, concentrated in particle size distribution, remarkably improved in dissolution rate and storage stability, and suitable for black and odorous water body treatment and industrial sewage treatment.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a modified sodium ferric sulfate positive electrode material as well as a preparation method and application thereof. The chemical structural formula of the modified sodium ferric sulfate positive electrode material is Na < 2 + 2x > (Fe < 1-a-b > MaMb < 2-x > (SO4) z (PO4) < 3-z, a is more than 0 and less than 1, b is more than 0 and less than 3, z is more than 0 and less than 3, Ma and Mb are transition metal elements, and Ma is Ni; and Mb is Zn. The transition metal element is introduced and the doping proportion is controlled, so that fine regulation and control on the material performance can be realized, the conductivity and the ion diffusion rate of the positive electrode material are improved, and the structural stability and the air stability of the material are enhanced; the problems of slow Na < + > diffusion kinetics, poor crystallinity and poor material air stability of the sodium ferric sulfate positive electrode material are solved, and a new possibility is provided for the development of a sodium ion battery technology.

The invention discloses a positive electrode material formed by compounding polyanionic sodium ferric sulfate and a layered transition metal oxide, and a preparation method and application thereof, and the preparation method comprises the following steps: preparing a sodium ferric sulfate positive electrode material, preparing a layered transition metal oxide positive electrode material, and mechanically mixing the sodium ferric sulfate and the layered transition metal oxide material, the composite material is obtained. The production process of the two materials is easy for large-scale production, has high similarity with the existing battery industrial equipment, is simple in method for compounding the two materials, and has large-scale industrial application value. The composite material has the stability of a polyanionic material and the high energy density of a layered oxide material, and has more excellent comprehensive electrochemical performance.

The invention provides a sodium vanadium fluorophosphate in-situ coated sodium ferric sulfate / carbon composite material and a preparation method thereof.The preparation method comprises the steps that raw materials including a reducing agent, an iron source, a sodium source and a carbon source are added into absolute ethyl alcohol to be stirred, sanded and mixed, and after obtained slurry is subjected to spray drying, the slurry is sintered and cooled in the argon atmosphere to obtain the sodium ferric sulfate / carbon composite material; mixing the sodium ferric sulfate / carbon composite material dispersion liquid with the sodium vanadium fluorophosphate precursor solution, performing hydrothermal reaction, centrifuging, washing and drying to obtain the sodium vanadium fluorophosphate in-situ coated sodium ferric sulfate / carbon composite material. According to the preparation method, a sodium vanadium fluorophosphate coating layer is generated on the surface of sodium ferric sulfate in situ by combining a low-temperature solid-phase method with a hydrothermal method, so that the sodium vanadium fluorophosphate in-situ coated sodium ferric sulfate / carbon composite material is obtained, the electronic conductivity of the composite material is greatly improved, and the sodium ion diffusion rate is promoted by coating of sodium vanadium fluorophosphate; fe2 + is prevented from being oxidized into Fe3 + due to direct contact between the sodium ferric sulfate and air, so that the air stability of the sodium ferric sulfate is improved.

The invention provides a method for recovering valuable metals from sulfuric acid process titanium white waste acid through steel slag treatment. The method comprises the following steps: recovering to obtain ferrous sulfate heptahydrate crystals; s2, recovering Sc metal, and extracting the filtrate in the step S1 to obtain a first loaded organic phase and a first raffinate; the first loaded organic phase is washed with alkali liquor, and a second loaded organic phase and washing water are obtained through reverse extraction; treating the washing water to obtain titanium phosphate; back-extracting the second loaded organic phase by using alkali liquor, carrying out filter pressing to obtain crude Sc (OH) 3, and refining to obtain scandium oxide; extracting the first raffinate to obtain a third loaded organic phase and a second raffinate, pickling the third loaded organic phase, reversely extracting with ammonia water, adding phosphoric acid for reaction, and treating to obtain titanium phosphate; and steel slag is added into the second raffinate for neutralization leaching and hydrolysis vanadium precipitation, vanadium-rich slag is obtained through filtering, and then the vanadium electrolyte is prepared. According to the method, iron is separated through crystallization, scandium and titanium are separated through extraction, vanadium-rich slag is separated through neutralization and precipitation, and efficient utilization of resources is achieved.

The invention relates to the technical field of sodium ion battery positive electrode materials, and discloses a process method for preparing a sodium ferric sulfate composite positive electrode material from a crystal water-free precursor and a sodium ion battery. The problems of low crystallinity of Na < 2 + > 2 < delta > Fe < 2-delta > (SO4) 3 and easy oxidation of Fe < 2 + > caused by water vapor generated when the Na2Fe (SO4) 2.4 H2O precursor is heated and hydrated are solved. On the basis, aiming at the defect of poor electronic conductivity of Na < 2 + 2 > < delta > Fe < 2-delta > (SO4) 3, the invention provides the Na < 2 + 2 > < delta > Fe < 2-delta > (SO4) 3 / C composite positive electrode material with improved conductivity, and the composite positive electrode material can show excellent high rate capacity and long cycle stability at room temperature and in high and low temperature environments, and has a relatively good prospect in the field of novel energy storage.

The invention relates to the technical field of battery material recovery, and particularly discloses a method for efficiently recovering lithium and ferrous sulfate heptahydrate in retired lithium iron phosphate through total leaching and green impurity removal. Comprising the following steps: 1, adding strong base and a carbon source into black powder, and calcining at high temperature in an inert atmosphere; step 2, dissolving in pure water after calcining, and carrying out suction filtration to obtain a lithium salt solution and ferrous hydroxide; 3, sulfuric acid is added into ferrous hydroxide for suction filtration, and graphite and a ferric salt solution are obtained; drying the ferric salt solution to obtain ferrous sulfate heptahydrate; step 4, adding alkali into the lithium salt solution to obtain a purified lithium salt solution; 5, introducing carbon dioxide into the purified lithium salt solution, and adding alkali to generate lithium carbonate precipitate; and 6, finally carrying out heat preservation, suction filtration, washing and drying to obtain a lithium carbonate finished product. The technical problems that in the prior art, a traditional decommissioned lithium iron phosphate battery grading recycling technology is complex in production process, more waste liquid pollution is generated, and the production cost is relatively high are solved.

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.

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: mixing and leaching battery black powder and sulfuric acid, and filtering to obtain a leaching solution; the pH of the leachate is controlled, ferrous sulfate in the solution is separated out through alcohol substances or ammonium sulfate, and ferrous sulfate precipitates or ammonium ferrous sulfate crystals and mother liquor are obtained after filtration; evaporating and concentrating the mother liquor, adding an impurity removing agent into the mother liquor, and extracting to obtain a phosphoric acid solution and a lithium-containing solution; after phosphoric acid is supplemented into the lithium-containing solution, the pH is adjusted to be 8-10, and battery-grade lithium phosphate precipitates are obtained. According to the method, iron in the leachate is separated out firstly, and the subsequent impurity removal difficulty is greatly reduced, so that recycling of three elements including phosphorus, iron and lithium in the battery black powder is facilitated, and the environmental problem caused by stacking of lithium extraction residues can be avoided.

The invention discloses a method and a system for recovering solid residues in titanium dioxide production by a fluorination method. The recovery method comprises the following steps: mixing and reacting solid residues obtained after titanium dioxide is produced by a fluorination method with concentrated sulfuric acid with the concentration of 95-100wt% at the temperature of 25 DEG C or above, so as to obtain ferric sulfate and hydrogen fluoride. According to the method for recycling the solid residues in the titanium dioxide produced through the fluorination method, FeF3 in the solid residues can be converted into Fe2 (SO4) 3 and HF to be recycled, waste is turned into wealth, H2SO4 used in the recycling method is wide in source, the requirement for technological conditions is low, pollution to the environment is small, and the method is suitable for industrial production. And clean production can be realized while the process energy consumption is reduced.

The invention belongs to the technical field of secondary batteries, and particularly relates to a sodium ferric sulfate positive electrode material as well as a preparation method and application thereof. The preparation method of the sodium ferric sulfate positive electrode material comprises the following steps: S1, mixing a sodium source, an iron source, a sulfur source, an antioxidant, multilayer graphene oxide and water to obtain spray slurry; the number of layers of the multi-layer graphene oxide is 10-50; s2, performing spray drying on the spray slurry to obtain a spray material; and S3, sintering and crushing the spray material obtained in the step S2 to obtain the sodium ferric sulfate positive electrode material. The sodium ferric sulfate positive electrode material prepared by the method has good compaction density, and the energy density and the cycling stability of the sodium ferric sulfate positive electrode material can be improved through the compaction density.

The invention relates to the technical field of battery recovery, and particularly discloses a recovery method of waste lithium iron phosphate and a lithium ion secondary battery. The recovery method of the waste lithium iron phosphate comprises the following steps: leaching acid liquor, and carrying out solid-liquid separation to obtain acid leaching liquor and a regenerated negative electrode material; cooling and crystallizing, and carrying out solid-liquid separation to obtain first iron-removed slag and first iron-removed liquid; oxidizing, adjusting pH, removing iron, and carrying out solid-liquid separation to obtain second iron-removed slag and second iron-removed liquid; adjusting the pH to precipitate lithium phosphate, and carrying out solid-liquid separation to obtain first lithium phosphate slag and lithium precipitation mother liquor; adding a lithium source into the lithium precipitation mother solution, and carrying out solid-liquid separation after reaction to obtain second lithium phosphate slag and a phosphorus removal solution; and evaporating and concentrating the dephosphorized solution to obtain a by-product salt. By implementing the invention, the recovery of each useful component can be realized.

The invention discloses a preparation method of iron phosphate with a high iron-phosphorus ratio. According to the method, a small amount of iron source is added in the process of dissolving and recrystallizing amorphous-state iron phosphate in the aging process, and the part of iron source enters crystalline-state iron phosphate, so that the utilization rate of a P element in a reaction system is increased, and meanwhile, the iron-phosphorus ratio of the prepared iron phosphate is increased.

The invention belongs to the technical field of titanium dioxide production by a sulfuric acid method, and particularly relates to a ferrous sulfate heptahydrate separating and washing process and a vertical centrifugal machine. According to the separation and washing process, a solid-liquid mixture transfer barrel, a vertical centrifugal machine, a ferrous collecting hopper, a humidifying and mixing conveyor, a ferrous spiral feeder, a horizontal pushing centrifugal machine, a ferrous spiral discharging machine, a titaniferous solution storage barrel, a light washing solution storage barrel, a concentrated washing solution storage barrel, a light washing solution conveying pump, a concentrated washing solution conveying pump and a titaniferous solution conveying pump are included. According to the invention, the investment is greatly reduced, and the plant area required by equipment installation is also greatly reduced; according to the capacity configuration of annual production of 30,000 tons of titanium dioxide, the required plant area is 150m, and the investment of core equipment is about 1500,000 yuan.

The invention relates to a method for separating iron, vanadium and titanium dioxide in vanadium titano-magnetite or titanium concentrate through a wet method, and belongs to the technical field of chemical engineering. The method comprises the following steps: (a) mixing vanadium titano-magnetite or titanium concentrate with sulfuric acid with the concentration of 22-30wt.% to obtain mixed slurry; (b) treating the mixed slurry at 150-200 DEG C and 2-4 MPa under the condition that the Reynolds number is gt; reacting in a turbulent flow state of 4000, so that non-titanium elements are dissolved to generate sulfate; (c) carrying out solid-liquid separation on the reaction product in the step (b) to obtain a high-grade titanium-rich material and waste liquid; (d) the titanium-rich material reacts with a sodium hydroxide solution, silicon in the titanium-rich material is removed, and a sodium silicate solution is generated; and (e) reacting the silicon-removed titanium-rich material with a hydrochloric acid solution with the mass concentration of less than 15%, cleaning, carrying out solid-liquid separation, and calcining to obtain anatase or rutile titanium dioxide. According to the method, all iron, vanadium and titanium elements in the vanadium-titanium-iron concentrate and the titanium concentrate are recycled.

The invention relates to the technical field of lithium ion batteries, and provides a method for preparing lithium iron phosphate by using a titanium dioxide byproduct ferrous sulfate and application. The invention relates to a method for preparing lithium iron phosphate by using a titanium dioxide byproduct ferrous sulfate, which comprises the following steps: dissolving the titanium dioxide byproduct ferrous sulfate, adding a purifying agent for purification treatment, and filtering to obtain a purified ferrous sulfate solution; the purified ferrous sulfate solution serves as electrolyte, Fe < 2 + > is partially oxidized into Fe < 3 + >, phosphoric acid is added into the obtained mixed valence iron solution, the pH is adjusted, and iron phosphate precursor slurry is formed through aging; mixing the iron phosphate precursor slurry with an ethanolamine-water mixed solution of lithium hydroxide, and carrying out a reaction in a microwave reactor to obtain a lithium iron phosphate precursor suspension; and crystallizing the lithium iron phosphate precursor, and simultaneously introducing a carbon source steam and a silicon source steam to carry out gas-phase surface modification to obtain the lithium iron phosphate material. According to the invention, the raw material purity is improved, the powder structure is improved, and the long-cycle stability is improved.

The invention discloses an electroplating sludge iron resource recovery method based on acid leaching-resin selective adsorption, and relates to the field of dangerous solid waste resource treatment.The electroplating sludge iron resource recovery method comprises the following steps that S1, collected electroplating sludge and sodium salt are evenly mixed, roasted, cooled, washed and filtered, and washing liquid and filter residues are obtained; s2, adding water into the filter residues obtained in the S1, uniformly mixing, then mixing with an acid solution, carrying out an acid leaching reaction, and carrying out solid-liquid separation to obtain an acid leaching solution; according to the electroplating sludge iron resource recycling method based on acid leaching-resin selective adsorption, selected specific chelating resin is large in iron ion adsorption capacity and excellent in selectivity under the low pH, competitive interference of coexisting ions such as Cu < 2 + > can be effectively overcome, and the iron recycling rate can reach 99% or above; the adsorption step is carried out under the strong acidic condition and is matched with the characteristics of the electroplating sludge pickle liquor, the pH does not need to be greatly adjusted, the process is simplified, and the cost is reduced.

The invention relates to a method for high-value utilization of waste lithium iron phosphate battery lithium extraction slag, and belongs to the technical field of waste lithium ion battery resource utilization. The method comprises the following steps: S1, mixing the lithium iron phosphate lithium extraction slag with a low-concentration sulfuric acid solution in proportion, carrying out countercurrent washing, carrying out solid-liquid separation, carrying out acid dissolution on a solid, carrying out gradient recycling on a washing solution, and carrying out resin adsorption and reverse osmosis treatment on a high-impurity washing solution for recycling; s2, reacting the pretreated solid with medium-concentration sulfuric acid, reducing a dissolved solution by using iron powder, then carrying out solid-liquid separation to obtain a first batch of ferrous sulfate heptahydrate, adding concentrated sulfuric acid into mother liquor, carrying out secondary crystallization, then carrying out solid-liquid separation, and recrystallizing the obtained solid by using washing wastewater to obtain a second batch of ferrous sulfate heptahydrate; s3, recovering sulfuric acid by adopting a membrane treatment method, and recovering phosphoric acid from residual mother liquor by adopting an extraction method; or directly treating the lithium iron phosphate waste residue. According to the method, efficient separation and recovery of iron and phosphorus resources and full-component high-value utilization of the lithium iron phosphate lithium extraction slag are realized.

The present invention discloses a method for removing impurities from waste acid and fully recycling the waste acid. The method comprises the following steps: introducing hydrogen sulfide into the waste acid for a sulfidation reaction, removing arsenic sulfide and mercuric sulfide precipitates formed during the reaction; continuing to introduce hydrogen sulfide for a step-by-step sulfidation reaction, adding an iron-containing substance to adjust the reaction pH and ORP, and recovering the copper, lead, and zinc sulfide slag precipitates formed during the reaction in a step-by-step manner; adding an iron-containing substance for a neutralization reaction, controlling the pH and ORP, promoting the reaction between iron ions and arsenate, and removing the ferric arsenate precipitate formed during the reaction; adding an adsorbent for an adsorption reaction, and removing fluorine-containing and thallium-containing components by adsorption; introducing an oxidant for an oxidative hydrolysis reaction, controlling the degree of hydrolysis, and preparing polyferric sulfate. The present invention utilizes the iron-containing substance to remove impurities from waste acid, thereby achieving deep impurity removal and full resource utilization of waste acid.

The invention discloses a resourceful treatment method for stainless steel pickling waste liquid and waste water. The waste liquid is divided into high-concentration waste liquid and low-concentration waste liquid according to the acid concentration and the salt concentration to be treated respectively. Sequentially recovering gypsum, chromic hydroxide, nickel sulfide, ferrous hydroxide and manganese-rich slag from the low-concentration waste liquid through gradient precipitation; and neutralizing free acid from the high-concentration waste liquid by using ferrous hydroxide generated in a low-concentration section, cooling and crystallizing to recover ferrous sulfate, deeply removing nickel by using nickel sulfide generated in the low-concentration section, and precipitating to recover chromium hydroxide. In the whole process, generation of ferric iron is strictly controlled, and high-value productization recovery of free acid and all metals is achieved. The method has the advantages of low medicament consumption, high metal recovery rate, high product value, no secondary pollution and the like.

The present invention provides a method for preparing polyferric sulfate from solid waste yellow ferrous sulfate in a titanium dioxide factory, comprising the following steps: dissolving the yellow ferrous sulfate raw material in water, adding iron oxide red under heating conditions, stirring until the reaction is complete, and then filtering to remove insoluble impurities; adding an oxidant to the filtrate, heating and stirring to carry out oxidation, hydrolysis, and polymerization reactions to obtain a liquid product; concentrating and drying the liquid product to prepare solid polyferric sulfate. The method neutralizes the free acid in the raw material yellow ferrous sulfate by adding iron oxide red, increases the content of effective component iron in the system, and the prepared product has a relatively high basicity and good polymerization effect, and no external acid or alkali is required during the preparation process. The present invention eliminates the environmental protection hidden danger caused by the stacking of solid waste, enables the comprehensive utilization of industrial waste by-products, reduces the production cost of polyferric sulfate, and improves the economic benefit of titanium dioxide production.

The invention relates to the field of chemical technology, in particular to a preparation device of temperature-controlled solid acid particles and a preparation method thereof. The device comprises a shell, a controller is installed on the outer side of the shell, a first partition is installed in the inner cavity of the shell, a first mixing mechanism is installed on the upper end of the first partition, a second mixing mechanism is installed on the bottom end of the inner cavity of the shell, and a stirring mechanism is installed on the upper end of the shell through a frame. Compared with the prior art, the device has reasonable structural design and strong practicability, is convenient for temperature control of the preparation process of solid acid particles (polyferric sulfate), is convenient for rapid cooling to reduce the solution temperature after sulfuric acid dilution, is convenient for rapid use, improves the production efficiency of polyferric sulfate, is convenient for mechanical linkage to rotate two stirring components in a linkage manner, reduces equipment cost, is convenient for filtering and collecting polyferric sulfate, and effectively improves the use effect.

The invention discloses a lithium iron phosphate positive electrode material recovery method, which comprises: (1) adding dilute phosphoric acid to positive electrode material powder to prepare a lithium iron phosphate slurry, and carrying out electrolysis extraction to recover the lithium element in the positive electrode material powder so as to obtain an iron phosphate slurry; and (2) adding concentrated sulfuric acid into the iron phosphate slurry obtained in the step (1) to carry out a dissolution reaction, then carrying out solid-liquid separation to obtain a ferric sulfate solution containing phosphoric acid, then adding iron blocks or iron powder to carry out a reaction, and then adjusting the iron-phosphorus ratio and the ferrous ion content of the system to obtain a ferrous solution meeting the requirements of ammonium-process iron phosphate. The recycling method of the lithium iron phosphate positive electrode material is simple in technological process, less in acid and alkali consumption, less in waste liquid and low in cost, valuable elements such as lithium, iron and phosphorus in the lithium iron phosphate positive electrode powder are recycled at low cost and high yield, and the extracted iron and phosphorus elements are presented in a ferrous solution and can be directly grafted with an existing ammonium-process iron phosphate device, so that the recycling method is suitable for industrial production. Good popularization prospects are realized.

The invention relates to a production process of polyferric sulfate. The production process comprises the following steps: a raw material treatment step: crushing and screening raw materials; an oxidation reaction step: adding an oxidizing agent into the treated raw materials for stirring reaction; and a polymerization reaction step: adding a polymerizing agent into the oxidized raw material for stirring reaction, removing impurities from the polymerized raw material, and drying to obtain a solid product. The problem that an oxidizing agent and a polymerizing agent react incompletely in an existing scheme is solved.

The present invention provides a reaction kettle for preparing polyaluminum ferric sulfate from the waste catalyst recycling tail liquid, belonging to the technical field of chemical reaction treatment. The reaction kettle includes a reaction kettle, and a circulation pump is arranged at the bottom of the reaction kettle to circulate the raw materials put into the reaction kettle through the circulation pump. After repeated circulation, the raw materials are mixed and stirred multiple times, avoiding the influence of the internal stirring component on the reaction quality of the raw materials, thereby improving the quality of polyaluminum ferric sulfate. The bottom of the conical eddy current chamber is fixedly connected with a return hopper arranged in the inner cavity of the reaction kettle, and the return hopper is communicated with the inner cavity of the conical eddy current chamber. The bottom of the return hopper is communicated with the liquid inlet of the circulation pump. During the mixing of the liquid, when the liquid passes through the eccentric flow holes on both sides, since the eccentric flow holes on both sides are symmetrically located at the eccentric positions, the liquid entering the conical eddy current chamber from both sides forms an eddy current, and the efficiency of liquid circulation is improved through the vortex-type liquid, thereby ensuring the stirring effect of the liquid raw materials.

The invention discloses a ferrous sulfate purification method and a ferrous sulfate purified product, and the method comprises the following steps: dissolving a titanium dioxide by-product in deionized water to obtain a ferrous sulfate saturated solution; under the condition that reducing gas is introduced into the ferrous sulfate saturated solution, mixing sodium sulfide with the ferrous sulfate saturated solution, and filtering to obtain a first purified solution; mixing sodium sulfide with the first purified solution, and filtering to obtain a second purified solution; and carrying out concentration crystallization on the second purified solution, and carrying out suction filtration and drying to obtain a ferrous sulfate purified product. Iron powder does not need to be added, oxidation of ferrous ions is inhibited through reducing gas, sodium sulfide is added in stages to enable impurities with high activity to react to generate sulfide precipitates, the sulfide precipitates are filtered, the content of impurities such as titanium ions, magnesium ions, manganese ions and calcium ions is greatly reduced, the impurity removal effect is good, and finally concentration and crystallization are conducted through solubility difference. The purification purity of the ferrous sulfate purified product is generally as high as 99% or above.

The invention discloses a preparation method of a solid-liquid combined multi-scale grain composition sodium ferric sulfate positive electrode material of a sodium ion battery, which comprises the following steps: S1, preparation of a precursor solution: mixing a sodium source, an iron source, sulfuric acid and an antioxidant by a wet method, and heating and dissolving to generate the precursor solution; s2, spray drying of the precursor powder: carrying out spray drying on the precursor solution, and drying to obtain dried precursor powder; s3, grading precursor powder grinding: in a protective atmosphere, mixing and grinding the precursor powder, sodium sulfate, ferrous sulfate and a conductive agent to form grading precursor powder; and S4, high-temperature calcination: carrying out high-temperature calcination on the graded precursor powder in a protective atmosphere to form a final sodium ferric sulfate material. The chemical formula of the sodium ferric sulfate is Na < 2 + 2x > Fe < 2-x > (SO4) 3, wherein x is more than or equal to 0 and less than or equal The method has the characteristics of high compaction density, excellent electrochemical performance and good processability.

The utility model relates to a polymeric ferric sulfate liquid oxygen adding device, which belongs to the technical field of material adding and comprises a reaction kettle body, a stirring shaft and a stirring motor, a stirring impeller is fixed on the stirring shaft, a distribution stirring rod is fixed on the outer wall of the lower portion of the stirring shaft, and a connecting rod is fixed on the inner side of the upper portion of the distribution stirring rod and fixed with the stirring shaft. A flow channel is arranged at the lower part of the stirring shaft, a cavity communicated with the flow channel is arranged in the distribution stirring rod, a plurality of distribution holes communicated with the cavity are formed in the outer side wall of the distribution stirring rod, a rotary joint is fixed at the bottom of the stirring shaft, the rotary joint is connected with a liquid oxygen adding pipe, and an electric valve is arranged on the liquid oxygen adding pipe. The distribution stirring rods are arranged on the lower portion of the stirring shaft, the distribution holes are evenly formed in the distribution stirring rods, liquid oxygen is added through the rotating connector and the liquid oxygen adding pipe, then the liquid oxygen is sprayed out of the distribution holes in a rotating mode, the liquid oxygen is added and mixed more evenly, and follow-up catalytic reaction is better facilitated.

The utility model relates to a copperas separating and washing system for titanium dioxide production, which is characterized in that an industrial water pipe and an ice maker cooling water pipe are combined and connected into a mixed water pipe, the mixed water pipe is connected with a three-stage washing water pipe through a booster pump, a plurality of nozzles are arranged at the tail end of the three-stage washing water pipe, and the nozzles are arranged above a disc filter; a first-stage distributor is arranged at the tail end opening of a first-stage washing water pipe connected to the first washing barrel, and the first-stage distributor is arranged above the disc filter; a second-stage distributor is arranged at the tail end opening of a second-stage washing water pipe connected to the second-stage washing barrel, and is arranged above the disc filter. Mixed water of ice maker cooling water and industrial water is used as third-stage washing water, so that the use amount of the ice maker cooling water is reduced, and energy is saved; the volume of three-stage washing water is stably controlled by adding a pump and an automatic regulating valve, so that the quality fluctuation of washed copperas caused by the change of water pressure and flow is avoided; three-stage washing water can be uniformly sprayed to the surface of copperas by the spray head, so that the copperas can be better cleaned, and the quality of the copperas is controlled.

The invention discloses a method for preparing battery-grade ferrous sulfate from a titanium dioxide byproduct ferrous sulfate, which comprises the following steps: (1) heating and dissolving the titanium dioxide byproduct ferrous sulfate in a solvent to form a ferrous sulfate supersaturated solution; (2) sequentially adding iron powder and sulfuric acid into the ferrous sulfate supersaturated solution, and carrying out reduction reaction; (3) adding a chelating agent into the solution obtained in the step (2), mixing, filtering, cooling, and carrying out solid-liquid separation to obtain recrystallized ferrous sulfate crystals and recrystallized saturated mother liquor; and (4) heating and dissolving the recrystallized ferrous sulfate crystal into a supersaturated solution by using a solvent, cooling and crystallizing, and repeating the recrystallization step to obtain the battery-grade ferrous sulfate. According to the method, a chemical chelation method and a recrystallization method are combined, sodium lignin sulfonate is added into the mother liquor as a chelating agent before the first recrystallization, the sodium lignin sulfonate and metal impurity ions form a stable compound, meanwhile, enrichment of the impurity ions in the mother liquor circulation process is avoided, and the purity of ferrous sulfate crystals is improved.