119results about "Cobalt carbonates" patented technology

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to cobalt carbonate and a preparation method thereof, cobaltosic oxide and a lithium ion battery. The crystal grain size of the cobalt carbonate (104) crystal face is 200-250, and the median particle size Dv50 is 16-20 [mu] m. The preparation method of the cobalt carbonate comprises the following steps: adding a precipitant solution and a cobalt salt solution into a reaction kettle in a parallel flow manner, carrying out a co-precipitation reaction, controlling the reaction pH value, starting a thickener when the volume of a material in the reaction kettle reaches a target value, continuing the reaction until large-particle cobalt carbonate slurry is obtained, and carrying out solid-liquid separation and washing to obtain the cobalt carbonate. Cobalt carbonate is subjected to first sintering, mixed with a doping agent and then subjected to second sintering, and cobaltosic oxide with the (311) crystal face grain size being 660-700 and the median particle size Dv50 being 14-18 microns is prepared. The cobaltosic oxide is high in mechanical strength and good in reaction activity with a lithium source, and the prepared lithium cobalt oxide positive electrode material is relatively excellent in electrochemical performance.

The invention discloses cobaltosic oxide, a preparation method thereof, lithium cobalt oxide, a positive pole piece and a battery, and relates to the technical field of lithium battery positive pole materials. The Dv50 of the cobaltosic oxide, the grain size D (111) of the (111) crystal face and the specific surface area BET meet the following relation: 3.33 [mu] m < 3 > / g < = # imgabs0 # < = 6.90 [mu] m < 3 > / g, wherein the Dv50 of the cobaltosic oxide is 3-20 [mu] m. The cobaltosic oxide is obtained by pre-sintering and calcining cobalt carbonate with the crystallinity of 30%-80% and the median particle size Dv50 of 3-22 [mu] m; the reaction activity of the cobaltosic oxide and a lithium source is high, the mechanical property is good, the lithium ion diffusion rate of the obtained lithium cobalt oxide is high, and the specific capacity and the first charge-discharge efficiency are relatively high.

The present disclosure relates to the technical field of new energy. Provided are cobaltosic oxide and cobalt carbonate and preparation methods therefor, a positive electrode material and a lithium-ion battery. Cobalt carbonate and corresponding cobaltosic oxide secondary particles are integrally subjected to gradient doping with Al, and the Al doping amount of a core layer thereof is higher than that of a coating layer, such that the crystal structure stability of an LCO material is improved, and the cycle performance of a lithium cobaltate battery prepared from a sintered positive electrode material is improved. The cobaltosic oxide comprises a core layer and a coating layer that coats the core layer, wherein the content of cobalt is reduced layer by layer from inside to outside, such that the surface Co4+ content is reduced, the Co dissolution amount is decreased, and the safety performance can be improved. The core layer is a functional layer, takes up a large proportion by volume, has a high cobalt content, and can improve the capacity and the cycle performance; and the coating layer is a modified layer, coats the core layer and is very thin, and the total content of doping elements is increased in a gradient manner, such that the specific performance of the material can be improved, and the comprehensive performance of LCO can be improved.

The invention discloses a method for extracting and recovering metal elements in a lithium battery by using a chlorination method, and belongs to the technical field of lithium battery recovery, the method comprises the following steps: step 1, roasting a lithium battery positive plate to remove organic matters, and stripping to remove aluminum foil to obtain electrode material powder; step 2, placing the electrode material powder on a carrier of a Joule heating device, carrying out thermal shock treatment in a chlorine atmosphere, and heating and chlorinating in stages in the treatment process; step 3, desublimating gas generated after chlorination in each stage; and 4, adding the desublimated solid in each stage into deionized water, mixing, adding a sodium carbonate aqueous solution, collecting the precipitate, washing, and drying to obtain a metal salt product. Based on the characteristics that Joule heat can rapidly heat and accurately control the temperature, by combining the difference between the temperature of chlorination reaction of different metal oxides and the gasification temperature of a chlorinated product, staged gasification desublimation treatment is achieved, different metal chlorides are obtained, and accurate and efficient purification is achieved.

The invention discloses a method for extracting and recovering metal elements in lithium batteries using a chlorination method, which belongs to the technical field of lithium battery recovery. The method comprises the following steps: step 1, calcining the positive electrode sheet of the lithium battery to remove organic matter, and peeling off the aluminum foil to obtain electrode material powder; step 2, placing the electrode material powder on a carrier of a Joule heat device, and performing a thermal shock treatment under a chlorine atmosphere, and the treatment process is staged by stage heating and chlorination; step 3, desublimating the gas generated after chlorination in each stage; step 4, adding the solid after desublimation in each stage to deionized water, adding a sodium carbonate aqueous solution after mixing, collecting the precipitate, washing and drying to obtain a metal salt product. The present invention is based on the characteristics of Joule heat that can heat quickly and accurately control the temperature, combined with the difference in the temperature of the chlorination reaction of different metal oxides and the gasification temperature of the chlorination product, to achieve staged gasification and desublimation treatment, obtain different metal chlorides, and purify accurately and efficiently.

The invention relates to high-aluminum-content basic cobalt carbonate and a preparation method thereof. The method comprises the following steps: 1) preparing a mixed solution from cobalt salt and aluminum salt; (2) adding a small amount of ammonium bicarbonate solution into a reaction kettle, starting heating, adding the mixed solution into the reaction kettle while stirring, controlling the pH value, and reacting to obtain a seed crystal dispersion liquid; and (3) adding the mixed solution and an ammonium bicarbonate solution into the seed crystal dispersion liquid, controlling the pH value, continuously reacting under heating and stirring until the particle size of the basic cobalt carbonate reaches a set value, stopping the reaction, and carrying out filter pressing, washing and drying to obtain the basic cobalt carbonate with high aluminum doping amount. The aluminum doping in the basic cobalt carbonate provided by the invention is as high as 7767-8357ppm, and the aluminum element is uniformly distributed and does not segregate.

The invention relates to composite-form aluminum-doped cobalt carbonate as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing a first carbonate solution, a second carbonate solution and an aluminum-doped cobalt salt solution; under the stirring condition, the aluminum-doped cobalt salt solution and the first carbonate solution are added into the second carbonate solution for a pre-reaction, and a reaction solution containing cobalt carbonate seed crystals is obtained; an aluminum-doped cobalt salt solution and a first carbonate solution are continuously added into the reaction solution, a first reaction and a second reaction are sequentially carried out, composite-form aluminum-doped cobalt carbonate particles are obtained, the second reaction comprises a first stage and a second stage, the mass ratio of the aluminum-doped cobalt salt solution to the first carbonate solution in the first stage is 1: 1-2: 1, and the mass ratio of the aluminum-doped cobalt salt solution to the second carbonate solution in the second stage is 1: 1-2: 1; and in the second stage, the mass ratio of the aluminum-doped cobalt salt solution to the first carbonate solution is (0.10: 1)-(0.25: 1). According to the preparation method disclosed by the invention, uniform dispersion of an outer-layer aluminum sheet is realized, and the uniformity of aluminum doping in cobalt carbonate is improved.

The invention provides phase-inversion-free aluminum-doped cobalt carbonate and a preparation method thereof, a positive electrode material and a battery, the preparation method comprises the following steps: feeding an aluminum-containing first cobalt salt solution and a first precipitant solution into a reaction device, and carrying out a first precipitation reaction to obtain a first reacted material containing first solid-phase particles; introducing a second cobalt salt solution and a second precipitant solution into the first reaction post-material, and carrying out a second precipitation reaction to prepare aluminum-containing cobalt carbonate, so as to obtain a second reaction post-material containing second solid-phase particles; wherein the average particle size of the second solid-phase particles is 2-3 [mu] m larger than that of the first solid-phase particles. According to the method, the aluminum-containing first cobalt salt solution is firstly adopted for the first precipitation reaction, then the aluminum-free second cobalt salt solution is adopted for the second precipitation reaction, and the mass concentrations of cobalt in the two stages of reactions are controlled to be the same, so that the aluminum segregation phenomenon in the highly aluminum-doped precursor can be greatly reduced, and the material percent of pass is improved.

The present invention discloses a cobalt oxide and a preparation method thereof, lithium cobalt oxide, a positive electrode sheet and a battery, and relates to the technical field of positive electrode materials for lithium batteries. The Dv50, the grain size D(111) of the (111) crystal plane and the specific surface area BET of the cobalt oxide satisfy the following relationship: 3.33 g ‑1 ≤#imgabs0#≤6.90g ‑1 , wherein the Dv50 of the cobalt oxide is 3-20 μm. The cobalt oxide is obtained by pre-sintering and calcining cobalt carbonate with a crystallinity of 30%-80% and a median particle size Dv50 of 3-22 μm; the cobalt oxide has high reactivity with the lithium source and good mechanical properties, and the obtained lithium cobalt oxide has a high lithium ion diffusion rate, thereby having a high specific capacity and initial charge and discharge efficiency.

The invention provides high-aluminum doped cobalt carbonate and a preparation method and application thereof, and the preparation method comprises the following steps: (1) injecting a cobalt-aluminum mixed salt solution, a carbonate solution and an organic weak acid solution into a base solution in a parallel flow manner, and carrying out a co-precipitation reaction to obtain a precursor; and (2) stopping injection of the organic weak acid solution, continuing to inject the cobalt-aluminum mixed salt solution and the carbonate solution, and carrying out a co-precipitation reaction to obtain the high-aluminum doped cobalt carbonate. According to the method, through segmented coprecipitation and control of the types of precipitants used for coprecipitation of all the segments, the doping amount and uniformity of aluminum in cobalt carbonate can be improved, aluminum segregation is avoided, and meanwhile high-aluminum-doped cobalt carbonate higher in sphericity degree and better in compactness can be obtained.

The present application provides a kind of cobalt carbonate, cobalt tetraoxide and preparation method, positive electrode material and lithium battery, and relates to the field of new energy technology. The cobalt tetraoxide is porous inside, and the pore distribution is uniform, and the particle size distribution (D90-D10) / (D90+D10) of the cobalt tetraoxide is in the range of 0.20-0.35. The particle size distribution is relatively narrow, and the consistency between particles is high, which is beneficial to the reaction activity of the prepared positive electrode material and the uniformity of crystal growth, improves the stability of the positive electrode material structure, and is beneficial to improve the cycle stability of the battery. The internal pores of the particles are uniform, which is beneficial to the uniform distribution of doping elements throughout the particles, which is beneficial to the stability of the rear-end positive electrode material structure and improves the battery cycle stability. The narrow particle size distribution and uniform distribution of pores inside the particles are beneficial to the controllability of crystal growth and particle size distribution of the rear-end positive electrode material, improve the stability of subsequent positive electrode material compaction, and are beneficial to improve the capacity and cycle stability of the battery.

The invention discloses an aluminum-magnesium co-doped cobalt carbonate precursor as well as a preparation method and application thereof. The preparation method comprises the following steps: respectively preparing a cobalt-aluminum mixed solution and a magnesium-containing precipitant solution; and adding the cobalt-aluminum mixed salt solution and the magnesium-containing precipitant solution into a base solution, and carrying out a co-precipitation reaction to obtain the aluminum-magnesium co-doped cobalt carbonate precursor. According to the method disclosed by the invention, the magnesium element is introduced into the precipitant solution in advance, so that magnesium ions can be complexed with the precipitant in advance, and the problems of nonuniform doping and segregation caused by difficult control of the precipitation rate of magnesium in the doping process are solved. According to the aluminum-magnesium co-doped cobalt carbonate precursor prepared by the method, magnesium and aluminum are uniformly doped, and the cycling stability of a lithium cobalt oxide battery can be effectively improved.

The invention provides a composite precursor, a composite positive electrode material, a secondary battery and electric equipment. The composite precursor comprises an inner core and an outer attaching layer arranged on at least part of the surface of the inner core, and the inner core and the outer attaching layer are both metal oxides or substances capable of being decomposed to form the metal oxides. The composite precursor and the active elements are chemically combined through selection of metal elements with different valence states in the inner core and the outer attachment layer, so that the substance of the inner core forms an active element-rich substance, and the substance of the outer attachment layer forms a positive electrode active substance; after the composite precursor is compounded with the active elements, the mole number of the active elements in each mole of the inner core material is larger than that of the active elements in each mole of the outer attachment layer material. The composite precursor can reduce the surface alkalinity of the lithium supplement agent and improve the air stability, so that the first-circle charging specific capacity of the secondary battery is improved.

The present invention relates to the technical field related to crude cobalt acid raw materials, and specifically provides a crude cobalt acid raw material pretreatment device, comprising: a frame, a base is fixedly installed inside the frame, a mixing tank is fixedly installed inside the base, a processing box is connected and installed on the upper inner side of the mixing tank, a pushing barrel is connected and installed at one end of the processing box, a fixed barrel is connected to the inside of the processing box away from the pushing barrel, a second rotating shaft is installed inside the pushing barrel, the processing box and the fixed barrel for common rotation, a driving mechanism is provided at one end of the second rotating shaft, an impurity removal mechanism is provided inside the processing box, an impurity removal pipe is connected and installed inside the fixed barrel, a first rotating shaft is provided inside the mixing tank, and discharge pipes are connected and installed at both ends of the inner bottom of the mixing tank. The present invention can remove impurities from the raw materials, and then improve the mixing effect with the solvent to make it more sufficient.

Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method for cobalt sulfate includes: a copper removal step (S1) of adding a sulfurizing agent to a cobalt chloride solution containing one or more impurities of copper, zinc, manganese, calcium, and magnesium and generating a precipitate of sulfide of copper to separate to remove copper; a neutralization step (S2) of adding a neutralizer or a carbonation agent to a cobalt chloride solution having undergone through the copper removal step (S1) and generating cobalt hydroxide or basic cobalt carbonate to separate magnesium; a leaching step (S3) of adding sulfuric acid to the cobalt hydroxide or the basic cobalt carbonate to obtain cobalt sulfate solution; and a solvent extraction step (S4) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant to the cobalt sulfate solution and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium. These steps are sequentially executed.

The invention provides a cobalt-based catalyst and a preparation method and application thereof, the chemical formula of the cobalt-based catalyst is Co (OH) x (CO3) 1-0.5 x, x is not higher than 2, and the cobalt-based catalyst has a nanofiber three-dimensional network structure. The cobalt-based catalyst provided by the invention has a nanofiber three-dimensional network structure, and the agglomeration phenomenon is greatly improved, so that the cobalt-based catalyst has a relatively high specific surface area, more active sites can be exposed, and the cobalt-based catalyst has excellent catalytic performance.

The invention discloses a method for recovering metal from electronic waste or leach residue thereof, the electronic waste or leach residue comprising copper element and one or more lithium compounds, the method comprising: leaching the electronic waste or leach residue with a leaching solution comprising ammonium sulfate in the presence of an oxidizing agent, a leaching solution containing copper ions and lithium ions and solid residues are provided; and separating the leachate and the solid residue.

A method of manufacturing a particulate transition metal carbonate material is described. The method includes mixing a transition metal precursor salt with a second salt in a liquid vehicle. A precipitation reaction is then performed to form a slurry of the particulate transition metal carbonate material in the liquid vehicle. The particulate transition metal carbonate material may find use as seeds in a subsequent precipitation reaction. Methods of manufacturing a particulate precursor materials are also described, including performing a precipitation reaction between one or more transition metal sources in the presence of seed particles in a reaction mixture within a precipitation reaction vessel, to form the particulate precursor material by precipitation onto the surface of the seed particles.

The application belongs to the technical field of new energy batteries, and particularly relates to a preparation method of aluminum-doped large-particle cobalt carbonate and application thereof. The preparation method of aluminum-doped large-particle cobalt carbonate disclosed by the application first prepares cobalt carbonate seeds, then continues to react after being separated into a kettle, and finally obtains aluminum-doped large-particle cobalt carbonate. By strictly controlling the process and process conditions of seed preparation and subsequent co-precipitation reaction, the uniformity of aluminum doping in cobalt carbonate is greatly improved, the aluminum distribution in the obtained tricobalt tetraoxide after calcination is more uniform, and the electrical performance of lithium ion batteries can be effectively improved. The preparation method of aluminum-doped large-particle cobalt carbonate disclosed by the application strictly controls the seed preparation process and the subsequent reaction process, so that the surface of the prepared cobalt carbonate particles is smoother, there is no segregation, and the sphericity is better, which is beneficial to improving the quality and service life of the final lithium ion battery product.

The application belongs to the technical field of water electrolysis catalysts, and discloses a NiFe-based bifunctional water decomposition electrocatalyst, a preparation method and application thereof, the catalyst is a core-shell heterostructure, a three-dimensional self-supporting NiFe-based OER / HER bifunctional electrocatalyst, specifically, a coral spherical NiFe-LDH coated basic cobalt carbonate nanowire nanomaterial NiFe-LDH@Co-CH / NF with a three-dimensional hierarchical porous core-shell heterostructure; the catalyst is prepared by a two-step method of hydrothermal and solvothermal, and the foam nickel is used as a conductive substrate, the inner layer is the basic cobalt carbonate nanowire, and the outer layer is the NiFe-LDH nanosheet. The catalyst has excellent OER and HER performance, significantly accelerates the diffusion and transfer of the electrolyte solution, excites the synergistic effect and electron transfer, and improves the catalytic activity of the catalyst. The water electrolysis system assembled by the catalyst has excellent water electrolysis performance, and has a wide application prospect.

The application provides an aluminum-manganese-nickel co-doped cobalt carbonate precursor and a preparation method and use thereof. The preparation method comprises the following steps: mixing a cobalt-aluminum mixed salt solution, a manganese salt solution, a nickel salt solution and a precipitant solution, and performing a co-precipitation reaction to obtain the aluminum-manganese-nickel co-doped cobalt carbonate precursor; wherein the cobalt-aluminum mixed salt solution comprises a complexing agent; the manganese salt solution comprises a first surfactant and a second surfactant, the first surfactant comprises a crown ether surfactant, and the second surfactant comprises a non-ionic surfactant. The preparation method provided by the application realizes uniform doping of aluminum, manganese and nickel in the cobalt carbonate precursor material, not only reduces the risk of low capacity caused by only increasing the aluminum content, but also reduces the risk of small particle explosion in the reaction process, so that the obtained tricobalt tetraoxide precursor material has uniform particle size and uniform distribution of doped elements.

The present invention provides a method for producing high-purity cobalt sulfate by separating impurities and cobalt from a cobalt chloride solution containing impurities without using an electrolysis process. The method sequentially implements the following steps: a decoppering step (S1), in which a sulfiding agent is added to a cobalt chloride solution containing one or more impurities selected from copper, zinc, manganese, calcium, and magnesium to form a copper sulfide precipitate, which is then separated and removed; a neutralization step (S2), in which a neutralizing agent or a carbonating agent is added to the cobalt chloride solution that has undergone the decoppering step (S1), to form cobalt hydroxide or alkaline cobalt carbonate, thereby separating the magnesium; a leaching step (S3), in which sulfuric acid is added to the cobalt hydroxide or alkaline cobalt carbonate to obtain a cobalt sulfate solution; and a solvent extraction step (S4), in which an organic solvent containing an alkylphosphoric acid-based extractant is brought into contact with the cobalt sulfate solution to extract zinc, manganese, and calcium into the organic solvent for separation and removal. The addition of the neutralizing agent or carbonating agent in the neutralization step (S2) is performed using a countercurrent multi-stage process.

The invention discloses a cobalt carbonate material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The cobalt carbonate material comprises an outer layer area and an inner layer area located on the inner side of the outer layer area, the inner layer area refers to an area formed by extending from the particle center of the cobalt carbonate material to the particle surface by the distance of (0.67-0.76) r, and r refers to the radius of the cobalt carbonate material particle; the cobalt carbonate material has a diffraction peak of a (101) crystal face in an X-ray diffraction pattern; the ratio of the diffraction peak intensity of the (101) crystal face of the cobalt carbonate material to the diffraction peak intensity of the (101) crystal face of the inner layer region is x1, and x1 is greater than 1.7; the cobalt carbonate material comprises a cobalt carbonate matrix and a nickel element doped into the cobalt carbonate matrix, and the phenomena of breaking, powder floating and the like during subsequent sintering preparation of the high-nickel-doped cobaltosic oxide material are avoided.

The present invention provides a method for preparing high-density small-particle cobalt carbonate, prepares a cobalt salt solution and an ammonium bicarbonate solution, adds them to a reaction vessel in a continuous feeding manner and reacts; in the initial stage of the continuous feeding stage, stops feeding at intervals and performs aging treatment, and continues to react after several agings until the seed crystal grows to a certain particle size; stops settling, siphons the supernatant, and then adopts a one-time feeding method to add the reaction solution to the reaction vessel, and continues to react under closed conditions to obtain a cobalt carbonate slurry; after washing, separation and drying, a high-density small-particle cobalt carbonate is obtained. The present invention is regularly aged at the initial stage of the reaction, effectively improving the defects of the seed crystal such as loose structure and poor density in the generation stage; adopts a combination of a continuous feeding method and a one-time feeding method, and in the crystal growth stage, the reaction time is effectively shortened by a one-time feeding, the production efficiency is improved, and the density and particle size consistency of the particles are further improved.

The invention relates to the related technical field of crude acid cobalt raw materials, and particularly provides crude acid cobalt raw material pretreatment equipment which comprises a frame body, a machine base is fixedly installed on the inner side of the frame body, a mixing tank is fixedly installed on the inner side of the machine base, and a treatment box is installed on the upper portion of the inner side of the mixing tank in a communicating mode; a material pushing barrel is installed at one end in the treatment box in a communicating mode, a fixing barrel is connected to the interior of the end, away from the material pushing barrel, of the treatment box, a second rotating shaft is jointly and rotationally installed in the material pushing barrel, the treatment box and the fixing barrel, a driving mechanism is arranged at one end of the second rotating shaft, and an impurity removing mechanism is arranged on the inner side of the treatment box; an impurity removal pipe is installed in the fixed cylinder in a communicating mode, a first rotating shaft is arranged on the inner side of the mixing tank, and discharging pipes are installed at the two ends of the bottom of the inner side of the mixing tank in a communicating mode.

The invention discloses cobalt carbonate, a preparation method and application, the cobalt carbonate comprises a cobalt carbonate inner core and an aluminum-doped cobalt carbonate coating layer coating the cobalt carbonate inner core, and the pore volume of the cobalt carbonate inner core is smaller than that of the cobalt carbonate. The cobalt carbonate in the application has a synergistic effect between a gradient pore structure and gradient aluminum doping distribution, so that the problem that cobalt carbonate particles are easy to crack and remove powder during sintering is solved, the sintered cobaltosic oxide can be kept to have relatively excellent tap density and mechanical strength, and the electrochemical performance of lithium cobalt oxide is further improved.

A bimodal lithium transition metal oxide based powder mixture comprises a first and a second lithium transition metal oxide based powder. The first powder comprises particles of a material A comprising the elements Li, a transition metal based composition M and oxygen. The first powder has a particle size distribution characterized by a (D90−D10) / D50≤1.5. The second powder comprises a material B having single crystal particles, said particles having a general formula Li+bN′−bO2, wherein −0.03≤b≤0.10, and N′=NixM″yCozEd, wherein 0.30≤x≤0.92, 0.05≤y≤0.40, 0.05≤z≤0.40 and 0≤d≤0.10, wherein M″ is one or both of Mn or Al, and E is a dopant different from M″. The first powder has an average particle size D50 between 10 and 40 μm. The second powder has a D50 between 2 and 4.5 μm. The weight ratio of the second powder in the mixture is between 15 and 60 wt %.

The invention provides basic cobalt carbonate with high carbonate content and a preparation method thereof, and belongs to the technical field of cobalt compound preparation. The basic cobalt carbonate can be used as a cobalt source or a cobalt compound precursor for a positive electrode material. The method comprises the following steps: introducing carbon dioxide into a sodium carbonate solution in advance to obtain a pre-carbonized sodium carbonate solution; synchronously dropwise adding the pre-carbonized sodium carbonate solution and the cobaltous sulfate solution for reaction under the condition of partial pressure of carbon dioxide, and controlling the pH value of the reaction solution to obtain reaction slurry; aging the reaction slurry under a carbon dioxide pressurization condition, regulating the pH value, and filtering to obtain a wet filter cake; the wet filter cake is sequentially subjected to sodium bicarbonate solution replacement washing and carbon dioxide saturated deionized water washing, then dried, smashed and screened, and a product is obtained; the method disclosed by the invention is beneficial to improving the carbonate introduction degree of basic cobalt carbonate and reducing soluble salt entrainment, and few insoluble residues are generated in acid medium dissolution evaluation.

The application provides a gradient washing method of cobalt carbonate, which comprises the following steps: first washing cobalt carbonate by using a washing liquid with a temperature of T1 at a flow rate of v1; then continuing to wash by using a washing liquid with a temperature of T2 at a flow rate of v2, and performing solid-liquid separation after the second washing to obtain washed cobalt carbonate; wherein T2 is less than T1, and v2 is greater than v1. The gradient washing method of cobalt carbonate can not only significantly reduce water consumption and energy consumption in the washing process, realize efficient and uniform removal of impurities, but also can simultaneously maintain the sphericity and surface state of cobalt carbonate particles by the cooperation of high-temperature low-flow and low-temperature high-flow washing.

The present invention belongs to the technical field of water treatment, and discloses an amorphous cobalt basic carbonate, a preparation method thereof and an application thereof. The preparation method comprises the following steps: S1. Mix cobalt nitrate hexahydrate and ethylene glycol to form a uniformly dispersed solution; S2. Control the temperature of the solution obtained in step S1 at 140-220 °C for solvent thermal reaction for 8-24 h; S3. Wash and dry the product obtained in step S2 to obtain amorphous cobalt basic carbonate. The application of amorphous cobalt basic carbonate as an adsorbent. The amorphous cobalt basic carbonate material prepared by the present invention has an ultra-high tetracycline adsorption capacity (up to 2746 mg / g), good cost-effectiveness, low biological toxicity and excellent recycling performance, and can efficiently remove tetracycline in water bodies.