CN114162872A

CN114162872A - Method for preparing battery-grade manganese sulfate from manganese oxide ore

Info

Publication number: CN114162872A
Application number: CN202111677462.3A
Authority: CN
Inventors: 郝江楠; 黄琳; 黄远平; 周向清
Original assignee: Hunan Xifu Environmental Protection Technology Co ltd
Current assignee: Hunan Xifu Environmental Protection Technology Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-03-11
Anticipated expiration: 2041-12-31
Also published as: CN114162872B

Abstract

The invention belongs to the field of smelting, and particularly relates to a method for preparing battery-grade manganese sulfate from manganese oxide ore, which comprises the following steps: leaching: performing first-stage leaching on manganese oxide ore, biomass and sulfuric acid, roasting leaching residues, mixing a roasting material and the first-stage leaching solution, performing second-stage leaching, and separating to obtain a leaching solution; impurity removal in the first stage: adding ferric sulfate, manganese series oxidant and sulfide into the leaching solution to obtain first-stage impurity-removing solution; ③ removing impurities in the second stage: performing manganese precipitation treatment on the first-stage impurity-removed liquid to obtain manganese hydroxide precipitate, dispersing the precipitate and the compound shown in the formula 1 in a solvent to obtain slurry, introducing carbon dioxide into the slurry, performing second-stage impurity removal, and performing solid-liquid separation to obtain impurity-removed manganese hydroxide; ③ removing impurities in the third stage: and dissolving the manganese hydroxide after impurity removal by using sulfuric acid, and then adding BaS and BaF2 to obtain a battery-grade manganese sulfate solution. The method has high recovery rate, and can prepare high-quality battery-grade manganese sulfate.

Description

Method for preparing battery-grade manganese sulfate from manganese oxide ore

Technical Field

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for preparing battery-grade manganese sulfate from manganese oxide ores.

Background

The battery-grade manganese sulfate is one of main raw materials for preparing a ternary cathode material of a lithium ion battery, and generally requires that the contents of K, Na, Ca and Mg in the battery-grade manganese sulfate are not higher than 50ppm, the contents of Fe, Cu, Zn and Pb are not higher than 10oom, the content of Cd is not higher than 5ppm, the content of As is less than 1ppm, and the content of F is less than 700 ppm; in addition, along with the subsiding of the electric vehicle, the manufacturing enterprises of the battery materials are forced to reduce the cost continuously. Therefore, the method has important significance for battery-grade manganese sulfate manufacturing enterprises by adopting low-grade raw materials and developing a low-cost impurity removal technology. At present, a plurality of processes for preparing battery-grade manganese sulfate in China have been developed, and the processes can be summarized into two routes of taking manganese products as raw materials and manganese ores as raw materials. The preparation of the battery-grade manganese sulfate by taking a manganese product as a raw material refers to the preparation by directly dissolving metal manganese or electrolytic manganese dioxide in acid or taking industrial manganese sulfate as a raw material and removing impurities; the process route of using manganese ore as raw material mainly includes the procedures of acid dissolution, impurity removal and the like.

Because elements such as K, Na, Ca, Mg, Fe, Cu, Zn, Pb and the like are inevitably present in manganese ore, particularly Ca and Mg are main associated elements in the manganese ore, and the lithiation property of the manganese ore is similar to that of manganese, more process technical routes are developed. Patent 201610001688.4 discloses a process for preparing battery-grade manganese sulfate from pyrolusite, which comprises the steps of reduction leaching with pyrite as a reducing agent, flocculation with activated carbon and a flocculating agent, ammonia water precipitation of manganese to obtain manganese hydroxide, washing of manganese hydroxide, and evaporation crystallization of acid-soluble manganese hydroxide and manganese sulfate. In the patents 200910161306.4 and 2011010137708.3, manganese sulfate products with impurity content reaching the battery grade standard are obtained by adopting processes including the working procedures of conversion, precipitation, washing, dissolution, fine filtration and the like, but the products of the processes are difficult to meet the requirement of producing high-quality cathode materials in the battery industry because no special working procedure is used for removing calcium and magnesium. The patent 201710552066.5 provides twoAlthough the scheme for preparing the battery-grade manganese sulfate by the stage extraction-sulfuric acid back extraction is simple in process, the problems of large extraction wastewater and the like exist. Paper "Helichrysum, Zhang Hai Jing, Xiong shan. MnSO₄Purification of solution and preparation of battery grade high-purity manganese sulfate [ J ]]Wet metallurgy, 2019,38(5):380-384) "provides a process for purifying a manganese sulfate solution, which mainly comprises the procedures of removing K and Na by jarosite method, removing iron by oxidation method, removing Ca and Mg by manganese fluoride, removing heavy metals by sulfides and the like, and although impurities such as K, Na, Ca, Mg, Fe, Cu, Zn, Pb and the like reach a low level, fluorine ions in the solution are not removed, and in addition, the flow is long and the process is complex. Patent 201810016993.X provides a method for removing calcium in manganese sulfate by a recrystallization method, but the recrystallization method has great difficulty in making calcium and magnesium in products reach the standard of high-end battery materials; research on preparation of battery-grade manganese sulfate by high-temperature crystallization and purification of industrial manganese sulfate [ J]The impurity content in manganese sulfate reaches the battery level standard through 3 times of crystallization and purification, but the repeated crystallization not only has higher energy consumption, but also seriously affects the recovery efficiency of the manganese sulfate.

Disclosure of Invention

The invention aims to prepare a battery-grade manganese sulfate solution by using manganese oxide ores with complex components.

A method for preparing battery-grade manganese sulfate from manganese oxidized ore comprises the following steps:

step (1): two stage leaching

Carrying out first-stage leaching on manganese oxide ore, biomass and sulfuric acid, and then carrying out solid-liquid separation to obtain first-stage leachate and leaching residues;

roasting the leached slag in an oxygen-free atmosphere, mixing the obtained roasted material with the first-stage leaching solution for second-stage leaching, and separating to obtain a leaching solution;

step (2): first stage impurity removal

Adding ferric sulfate and manganese series oxidants into the leaching solution, heating to carry out a first-stage precipitation reaction for precipitating sodium and/or potassium, then adding sulfide into the system, carrying out a second-stage precipitation reaction for heavy metals, and then separating to obtain a first-stage impurity removal solution;

and (3): second stage impurity removal

Performing manganese precipitation treatment on the first-stage impurity-removed liquid to obtain manganese hydroxide precipitate, dispersing the precipitate and the compound shown in the formula 1 in a solvent to obtain slurry, introducing carbon dioxide into the slurry, performing second-stage impurity removal, and performing solid-liquid separation to obtain impurity-removed manganese hydroxide;

r is H, alkyl, carboxyl or substituted alkyl; or R and the amino ring are synthesized into a five-membered or six-membered ring group;

m is H⁺、Na⁺、K⁺Or NH₄ ⁺；

And (4): third stage impurity removal

Dissolving the manganese hydroxide after impurity removal by using sulfuric acid, then adding BaS and BaF2, finally adding aluminum sulfate or a defluorinating agent, and carrying out solid-liquid separation after treatment to obtain a battery-grade manganese sulfate solution.

According to research, the two-stage leaching process and the combination of the first-stage impurity removal process and the third-stage impurity removal process are innovatively adopted, so that the extraction and recovery rate of manganese can be improved, the separation selectivity of manganese and other impurity elements can be improved, and a battery-grade manganese sulfate solution can be synergistically prepared.

In the present invention, the manganese oxide ore may be a mineral containing an oxide such as manganese dioxide, which is known in the industry. For example, the manganese oxide ore is at least one of pyrolusite, psilomelane, and manganite.

In the technical scheme of the invention, the method can be applied to any grade of manganese oxide ore theoretically, and particularly aims at the minerals which are difficult to process in the industry and have high Ca and Mg contents (5-15%). According to the technical scheme, no special requirement is required for the grade of the manganese oxide ore, high-grade and low-grade minerals can be effectively prepared into the battery-grade manganese sulfate solution by using the method, and the low-grade manganese oxide ore with the grade of 15-25% can be adopted in the invention in consideration of maximization of economic value.

In the present invention, the manganese oxide ore may be subjected to a treatment such as crushing in advance based on a conventional method. For example, the particle size of the manganese oxide ore is controlled below 150 um.

In the invention, the two-stage combined leaching is carried out with the assistance of a reducing agent, so that the improvement of the leaching of manganese is facilitated, and the subsequent selective separation of manganese and impurities is facilitated.

In the invention, the biomass is biomass waste containing at least one of cellulose, hemicellulose or crude fiber. For example, the biomass is at least one of straw, corn stalk or corn cob;

the biomass can be dehydrated and pulverized before use, for example, the particle size of the biomass is controlled to be 38um-74 um;

preferably, the mass ratio of the manganese oxidized ore to the biomass waste is (1:1) - (3: 1);

preferably, the concentration of the sulfuric acid is 1-3 mol/L;

preferably, the liquid-solid ratio of the first stage leaching stage is (3-10):1 (mL/g);

preferably, the temperature of the first stage leaching stage is 85-95 ℃;

preferably, the time of the first leaching stage is 4-10 h.

In the invention, the first-stage leaching slag is roasted, and then the first-stage leaching solution is adopted for second-stage leaching treatment, so that the improvement of manganese leaching is facilitated, and the separation of manganese and impurity elements is facilitated.

In the present invention, the oxygen-free atmosphere is, for example, at least one of nitrogen and inert gas;

preferably, the temperature of the roasting is 850-1000 ℃;

preferably, the roasting time is 2-4 h;

the slag is roasted and then treated by the first leaching solution, which is beneficial to improving the recovery of manganese and is also beneficial to impurity removal of the leaching solution, thereby being beneficial to the subsequent separation of manganese and impurities.

Preferably, the temperature of the second stage leaching stage is 50-70 ℃;

preferably, the time of the second stage leaching stage is 0.5-2 h.

In the invention, the obtained leachate is subjected to a jarosite (sodium) process in advance to realize the selective separation of sodium and/or potassium and manganese in the system, and then sulfide can be directly added without solid-liquid separation, so that the second-stage precipitation of heavy metals is realized.

In the step (2), the pH of the initial solution of the first-stage precipitation reaction is 1.5-2;

preferably, manganese hydroxide is used to regulate said pH;

preferably, the dosage of ferric sulfate is 40-50 times of the total amount of sodium ions and potassium ions in the leaching solution;

preferably, the manganese-based oxidizing agent is a manganese oxide having a valence of positive four or more, preferably manganese dioxide;

preferably, the using amount of the manganese-based oxidant is 8-10 times of the total mass of sodium ions and potassium ions in the leachate;

preferably, the temperature of the first precipitation reaction is greater than or equal to 90 ℃; the reaction time is preferably 1 to 2 hours, and the reaction is preferably followed by standing for 1 to 2 hours.

In the step (2), the pH of the initial solution of the second-stage precipitation reaction is 5.5-6; preferably, manganese hydroxide is used to regulate said pH;

preferably, the sulfide is sodium ferulate. In the invention, sodium feramete is used as a precipitator, so that manganese and heavy metal elements can be selectively separated.

In the present invention, the heavy metal is, for example, Pb, Co, Ni, Cd, As, Cu, Zn, etc.

Preferably, the dosage of the sulfide is 15 to 20 times of the total mass of the heavy metals in the solution system;

preferably, the time of the second-stage precipitation reaction is 1-2 h;

preferably, after the second-stage precipitation reaction, standing for 1-2 hours, and then carrying out solid-liquid separation to obtain the first impurity-removed liquid.

In the invention, the solution after the first stage impurity removal is subjected to precipitation treatment, and calcium hydroxide and magnesium hydroxide impurities in the solution are selectively and synergistically dissolved out by adopting a process under the assistance of a formula 1 and carbon dioxide, so that the selective separation of manganese and calcium-magnesium is realized.

In the present invention, in the step (3), the alkali used in the manganese precipitation treatment stage may be ammonia water, sodium hydroxide, potassium hydroxide, etc., and the alkali is preferably ammonia water in view of the simplicity of the treatment.

Preferably, the concentration of the ammonia water is 6-10 mol/L;

preferably, the end point of the manganese precipitation reaction is 10-11.5.

In the present invention, the combination of formula 1 and carbon dioxide gas is the key to improving the selective separation of manganese and calcium-magnesium.

Preferably, the alkyl is a straight chain or straight chain alkyl of C1-C10;

preferably, the substituted alkyl is a C1-C10 straight-chain or straight-chain alkyl containing 1-3 substituents; the substituent is hydroxyl, alkoxy of C1-C4, aminoacyl, acylamino, carboxyl, sulfydryl, alkylsulfydryl of C1-C4, phenyl, substituted phenyl, five-membered heterocyclic aryl, benzo six-membered heterocyclic aryl or amidino;

preferably, R is H, C1-C4 alkyl, hydroxyl substituted C1-C4 alkyl or phenyl substituted C1-C4 alkyl;

preferably, the compound shown in the formula 1 is not less than the theoretical reaction amount, and preferably 1-2 times of the theoretical reaction molar amount;

preferably, the solvent in the slurry is water or a mixed solvent of water and an organic solvent, and the organic solvent can be, for example, C1-C4 alcohol;

preferably, in the slurry, the weight ratio of the solvent to the manganese hydroxide to be treated is 1-10: 1;

preferably, in the second-stage impurity removal process, the end point pH value of the introduced carbon dioxide is 6.5-7.5; more preferably 6.8 to 7.2.

In the invention, carbon dioxide is introduced to reach the pH value, and then solid-liquid separation is carried out to obtain the treated manganese hydroxide.

In the invention, the manganese hydroxide after impurity removal is redissolved by sulfuric acid, and then the combined impurity removal component of BaS and BaF2 is adopted, which is beneficial to further improving the selective separation of manganese and other impurities (such as iron, calcium, magnesium and the like).

In the step (4), the concentration of the sulfuric acid is 50-70%;

preferably, the temperature of the acid dissolution stage is 70-95 ℃;

preferably, the pH value of the manganese sulfate solution after acid dissolution is 5.5-6;

preferably, the addition concentration of BaS is 0.5-1 g/L;

the addition concentration of BaF2 is 0.5-1 g/L.

After the combined treatment of BaS and BaF2, aluminum sulfate or a fluorine removal agent is adopted for treatment, and the battery-grade manganese sulfate solution is prepared. In the invention, the application concentration of the aluminum sulfate is 3-5 g/L; the application concentration of the fluorine removing agent is 1-2 g/L.

The prepared manganese sulfate solution can be used for further preparing corresponding products based on the existing means.

The invention relates to a method for preparing battery-grade manganese sulfate from pyrolusite, which comprises the following steps:

step one, efficient reduction leaching of manganese elements in pyrolusite;

removing impurity ions except calcium and magnesium in the pickle liquor;

step three, removing the precipitated manganese in the ammonia water and the calcium and magnesium in the manganese hydroxide;

acid dissolution of manganese hydroxide, deep impurity removal of manganese sulfate solution, and concentration and crystallization of the manganese sulfate solution.

The efficient reduction leaching of the manganese element in the pyrolusite in the step one refers to wet leaching by taking biomass waste as a reducing agent and sulfuric acid as a leaching agent, and filtering to obtain pickle liquor and leaching slag, wherein the leaching process comprises the following steps:

adding pyrolusite and biomass waste in the mass ratio of (1:1) - (3:1) into 1-3mol/L sulfuric acid solution, and reacting at 85-95 ℃ for 4-The liquid-solid ratio (mL/g) in the reaction system is (3-10):1 for 10 h. The low-grade pyrolusite refers to manganese dioxide ore with the Mn grade of about 20 percent, and the granularity is less than 150 um; the biomass waste used as the reducing agent refers to biomass waste rich in cellulose, hemicellulose or crude fiber and the like, wherein the cellulose, the hemicellulose or the crude fiber can be hydrolyzed into reducing sugar under acidic conditions, preferably any one of straw, corn stalk or corncob, and the particle size is 38um-74 um. The main reaction of the first step comprises the hydrolysis reaction of cellulose and hemicellulose in the biomass waste into glucose, oligosaccharide or monosaccharide under the action of concentrated sulfuric acid, and the reductive saccharides and MnO with oxidability₂Oxidation reduction reaction is carried out, the + 4-valent manganese in the pyrolusite is reduced into the + 2-valent manganese, and the reaction formula of the whole leaching process is as follows:

(C₆H₁₀O₅)n+nH₂SO₄→n(C₅H₁₁O₅)HSO₄

n(C₅H₁₁O₅)HSO₄+nH₂O→(C₆H₁₂O₆)n+nH₂SO₄

12MnO₂+C₆H₁₂O₆+12H₂SO₄→12MnSO₄+6CO₂+18H₂O

the overall reaction formula is: 12MnO₂+(C₆H₁₂O₆)n+12nH₂SO₄→12MnSO₄+6nCO₂+17nH₂O

The first step also comprises the deep recovery of manganese in the leached slag, firstly, the leached slag is subjected to heat treatment, namely, the slag is placed in a high-temperature furnace isolated from air, the temperature is raised to 850-1000 ℃ at the temperature rise rate of 5-20 ℃/min, then the temperature is kept for 2-4h, the positive pressure range in the high-temperature furnace is maintained to be 0.1-0.2MPa, then, the heat-treated slag is added into acid leaching solution maintained at the temperature of 50-70 ℃ for continuous stirring reaction, so that the manganese in the heat-treated slag is fully dissolved out, meanwhile, the removal of organic matters in the acid leaching solution is realized, and after the stirring reaction is carried out for 0.5-2 h, the obtained filtrate is the acid leaching solution after the removal of the organic matters. Dipping in waterThe reason why the manganese element in the slag is efficiently leached after the slag is subjected to heat treatment is as follows: the biomass waste used as the reducing agent cannot be saccharified in its entirety in the aforementioned reduction leaching process, and a large amount of organic matter component C remains_nH_mO, which generates reducing substances including CO and C when subjected to high-temperature heat treatment in the absence of air, which convert pyrolusite MnO₂Reducing to MnO, MnO and residual H in acid leaching solution₂SO₄Generation of MnSO₄The main reaction formula of (1) is as follows:

2MnO₂+C→2MnO+CO₂

MnO₂+CO→MnO+CO₂

MnO+H₂SO₄→MnSO₄+H₂O

the second step of removing other impurity ions except calcium and magnesium in the pickle liquor refers to removing K, Na, Fe, Al, Pb, Co, Ni, Cd, As, Cu, Zn and other elements in the pickle liquor, and the specific steps comprise:

step 1, using Mn (OH)₂Adjusting the pH of the acid leaching solution after removing the organic matters to 1.5-2, and adding K into the solution system⁺、Na⁺Fe 40-50 times of the sum of ion masses₂(SO₄)₃With 8-10 times of MnO₂，MnO₂Is added to oxidize the +2 valent iron ions in the solution to +3 valent; then, heating the solution to over 90 ℃, reacting for 1-2h, standing for 1-2h, wherein K in the solution⁺、Na⁺The ions enter the precipitate in the form of jarosite and jarosite. The main reaction of the step is as follows:

2Fe²⁺+MnO₂+4H⁺→2Fe³⁺+Mn²⁺+2H₂O

K⁺+3Fe³⁺+2SO₄ ^2-+6H₂O→KFe₃[SO₄(OH)₃]₂↓+6H⁺

Na⁺+3Fe³⁺+2SO₄ ^2-+6H₂O→NaFe₃[SO₄(OH)₃]₂↓+6H⁺

step 2, continuing to use Mn (OH)₂Adjusting the pH value of the solution system to 5.5-6, then adding sodium dimethyl dithiocarbamate 15-20 times the sum of the mass of heavy metal elements such As Pb, Co, Ni, Cd, As, Cu and Zn in the solution system, stirring for reaction for 1-2h, standing for 1-2h, and then filtering to obtain the manganese sulfate solution with other impurities except calcium and magnesium removed. The reaction occurring in this step is mainly Fe³⁺Hydrolysis reaction of (2) and heavy metal ion Me²⁺(Me ═ Pb, Co, Ni, Cd, Cu and Zn) with sodium ferulate:

Fe³⁺+3H₂O→Fe(OH)₃↓+3H⁺，2[(C₂H₅)₂NCSS]^-+Me²⁺→[(C₂H₅)₂NCSS]₂Me↓

the step three refers to the steps of precipitating manganese by ammonia water and removing calcium and magnesium in manganese hydroxide,

step 1, adding ammonia water to precipitate manganese. And D, adding ammonia water into the manganese sulfate solution obtained in the step two after impurities except calcium and magnesium are removed, so that manganese in the solution is precipitated in the form of manganese hydroxide, wherein the concentration of the added ammonia water is 6-10mol/L, and the end-point pH value of the solution is 10-11.5 after the ammonia water is added. Because calcium and magnesium ions are difficult to remove cleanly in the previous step, the reaction of the step comprises a manganese ion precipitation reaction and a calcium ion precipitation reaction in which magnesium ions and calcium sulfate are slightly dissolved into the solution, and the method comprises the following specific steps:

Mn²⁺+2NH₄OH→Mn(OH)₂↓+2(NH₄)⁺

Ca²⁺+2NH₄OH→Ca(OH)₂↓+2(NH₄)⁺

Mg²⁺+2NH₄OH→Mg(OH)₂↓+2(NH₄)⁺

and 2, pulping and carbonating the manganese hydroxide precipitate.

According to the liquid-solid ratio (3-5):1, deionized water and the manganese hydroxide precipitate are pulped, the formula 1 is added into the slurry, then carbon dioxide is introduced into the system until the pH value of the slurry reaches 6.8-7.2, the introduction of the carbon dioxide is stopped, and the filtration is carried out immediately, at the moment, a small amount of calcium hydroxide and magnesium hydroxide solids existing in the manganese hydroxide completely enter a liquid phase, so that the removal of calcium and magnesium in the manganese hydroxide is realized.

The compound of formula 1 is formula 1-A

Formula 1-B

Formula 1-C

The addition amount of the one of the calcium and the magnesium is 10-15 times of the total mass of the calcium and the magnesium in the solution. The reaction is as follows:

and (3) carbonation reaction: ca (OH)₂+2CO₂→Ca(HCO₃)₂，Mg(OH)₂+2CO₂→+Mg(HCO₃)₂

Reaction of formula 1-A: ca²⁺+Mg²⁺+4(C₄H₉NO₃)→[Ca(C₄H₉NO₃)₂]²⁺+[Mg(C₄H₉NO₃)₂]²⁺

Reaction of formula 1-B: ca²⁺+Mg²⁺+4(C₉H₁₁NO₂)→[Ca(C₉H₁₁NO₂)₂]²⁺+[Mg(C₉H₁₁NO₂)₂]²⁺

Reaction of formula 1-C: ca²⁺+Mg²⁺+4(C₂H₅NO₂)→[Ca(C₂H₅NO₂)₂]²⁺+[Mg(C₂H₅NO₂)₂]²⁺

The acid dissolution of the manganese hydroxide, the deep impurity removal of a manganese sulfate solution and the concentration and crystallization of the manganese sulfate solution in the step four comprise the following steps:

step 1, dissolving manganese hydroxide in acid. Adding the manganese hydroxide prepared in the third step after calcium and magnesium removal into 50-70% sulfuric acid solution, controlling the end point pH value to be 5.5-6, and then heating to 70-95 ℃; the reaction is as follows:

Mn(OH)₂+H₂SO₄→MnSO₄+2H₂O

and step 2, deeply purifying the manganese sulfate solution. Adding 0.5-1g/L BaS and 0.5-1g/L BaF into the solution₂Stirring for 1-2h to remove residual heavy metal ions and calcium and magnesium ions in the solution; then adding 3-5g/L aluminum sulfate or 1-2g/L commercial defluorinating agent (conventional defluorinating agent), stirring for 1-2h, and standing for 1-2 h; and finally, performing precision filtration.

The main reaction is as follows:

BaS+Me²⁺+SO₄ ^2-→MeS↓+BaSO₄↓

2BaF₂+Ca²⁺+Mg²⁺+2SO₄ ^2-→2BaSO₄↓+BaF₂↓+MgF₂↓

Al³⁺+3F^-→2AlF₃↓，Al³⁺+3H₂O→Al(OH)₃↓+3H⁺

and step 3, concentrating and crystallizing the manganese sulfate by adopting the known technologies such as MVR and the like to finally obtain the battery-grade manganese sulfate.

Compared with the prior art, the invention has the following advantages:

(1) by adopting the biomass-assisted two-stage leaching process, the recovery rate of manganese ore can be improved, impurity removal and impurity removal are facilitated, and the subsequent impurity removal effect is improved. In addition, straw, corn stalk or corncob biomass waste is waste in other industries, and the waste is applied to the leaching process of manganese ore, so that the aim of treating waste by waste can be fulfilled; moreover, the biomass waste materials adopted by the invention are rich in cellulose, hemicellulose or crude fiber and other components, and the components can be hydrolyzed into carbohydrate substances with strong reducibility under an acid environment, so that the valuable components in the manganese ore and slag roasting materials are reduced into low-value elements which are easy to be leached by acid, and high leaching efficiency can be obtained.

(2) The reducing slag generated in the reduction leaching process is subjected to heat treatment and then reacts with the pickle liquor, so that the manganese element in the slag is leached twice, the comprehensive recovery rate of manganese in the pyrolusite is improved, and carbon components in the reducing slag are subjected to heat treatment to generate carbon materials with good adsorption effect, so that impurities such as organic matters in the pickle liquor can be removed.

(3) The manganese sulfate solution is precipitated by alkali, and is further matched with a combined process of a formula 1-carbon dioxide, so that the selective separation of soluble impurities (such as N, Na and the like), calcium-magnesium and manganese can be realized. The method not only can reduce the trouble caused by the process that calcium and magnesium need to be removed by adding a large amount of fluoride and then need to remove fluorine, but also has no environmental pollution and low cost for removing calcium and magnesium.

(4) Mixing small amount of BaS and BaF₂The advanced treatment of manganese sulfate solution is combined because of BaSO₄Solubility product of 1.08X 10^-10(25 ℃ C.) to BaF₂1.84X 10^-7The method is nearly 3 orders of magnitude lower, so that the method can realize the deep removal of heavy metals such as Cu, Pb, Zn, Ni, Co and the like, Ca and Mg, and simultaneously does not introduce other cationic impurities, thereby being a great advantage compared with other known technologies.

Drawings

FIG. 1 is a flow chart of an embodiment of the present invention

Detailed Description

The following further describes the practice of the present invention with reference to the drawings, but the present invention is not limited thereto.

See fig. 1.

The invention provides a method for preparing battery-grade manganese sulfate from low-grade pyrolusite, which comprises the following steps:

step one, efficient reduction leaching of manganese elements in pyrolusite;

removing impurity ions except calcium and magnesium in the pickle liquor;

The efficient reduction leaching of the manganese element in the pyrolusite in the step one refers to wet leaching by taking biomass waste as a reducing agent and sulfuric acid as a leaching agent, and filtering to obtain pickle liquor and leaching slag, wherein the leaching process comprises the following steps: adding pyrolusite and biomass waste into 1-3mol/L sulfuric acid solution according to the mass ratio of (1:1) - (3:1), and reacting at 85-95 ℃ for 4-10h, wherein the liquid-solid ratio (mL/g) in the reaction system is (3-10): 1. The low-grade pyrolusite refers to manganese dioxide ore with the Mn grade of about 20 percent, and the granularity is less than 150 um; the biomass waste used as the reducing agent refers to biomass waste rich in cellulose, hemicellulose or crude fiber and the like, wherein the cellulose, the hemicellulose or the crude fiber can be hydrolyzed into reducing sugar under acidic conditions, preferably any one of straw, corn stalk or corncob, and the particle size is 38um-74 um.

The first step also comprises the deep recovery of manganese in the leached slag, firstly, the leached slag is subjected to heat treatment, namely, the slag is placed in a high-temperature furnace isolated from air, the temperature is raised to 850-plus-one temperature 1000 ℃ at the temperature rise rate of 5-20 ℃/min, then the temperature is kept for 2-4h, the positive pressure range in the high-temperature furnace is maintained to be 0.1-0.2MPa, then, the heat-treated slag is added into acid leaching solution (the last step) maintained at the temperature of 50-70 ℃ for continuous stirring reaction, so that the manganese in the heat-treated slag is fully dissolved out, meanwhile, the removal of organic matters in the acid leaching solution is realized, and after the stirring reaction is carried out for 0.5-2 h, the obtained filtrate is filtered to be acid leaching solution after the removal of the organic matters.

step 1, using Mn (OH)₂Adjusting the pH of the acid leaching solution after removing the organic matters to 1.5-2, and adding K into the solution system⁺、Na⁺Fe 40-50 times of the sum of ion masses₂(SO₄)₃With 8-10 times of MnO₂，MnO₂Is added to oxidize the +2 valent iron ions in the solution to +3 valent; then, heating the solution to over 90 ℃, reacting for 1-2h, standing for 1-2h, wherein K in the solution⁺、Na⁺The ions enter the precipitate in the form of jarosite and jarosite.

Step 2, continuing to use Mn (OH)₂Adjusting the pH value of the solution system to 5.5-6, then adding sodium dimethyl dithiocarbamate 15-20 times the sum of the mass of heavy metal elements such As Pb, Co, Ni, Cd, As, Cu and Zn in the solution system, stirring for reaction for 1-2h, standing for 1-2h, and then filtering to obtain the manganese sulfate solution with other impurities except calcium and magnesium removed.

step 1, adding ammonia water to precipitate manganese. And D, adding ammonia water into the manganese sulfate solution obtained in the step two after impurities except calcium and magnesium are removed, so that manganese in the solution is precipitated in the form of manganese hydroxide, wherein the concentration of the added ammonia water is 6-10mol/L, and the end-point pH value of the solution is 10-11.5 after the ammonia water is added. Because calcium and magnesium ions are difficult to remove cleanly in the previous step, the reaction of the step comprises the precipitation reaction of manganese ions and the precipitation reaction of magnesium ions and calcium ions which are slightly soluble in calcium sulfate and enter the solution.

And 2, pulping and carbonating the manganese hydroxide precipitate.

According to the liquid-solid ratio (3-5):1, deionized water and the manganese hydroxide precipitate are pulped, the formula 1 is added into the slurry, then carbon dioxide is introduced into the system until the pH value of the slurry reaches 6.8-7.2, the introduction of the carbon dioxide is stopped, and the filtration is carried out immediately, at the moment, a small amount of calcium hydroxide and magnesium hydroxide solids existing in the manganese hydroxide completely enter a liquid phase, so that the removal of calcium and magnesium in the manganese hydroxide is realized. The compound of formula 1 is shown as formula 1-A

Formula 1-B

Formula 1-C

The addition amount of the one of the calcium and the magnesium is 10-15 times of the total mass of the calcium and the magnesium in the solution.

step 1, dissolving manganese hydroxide in acid. Adding the manganese hydroxide prepared in the third step after calcium and magnesium removal into 50-70% sulfuric acid solution, controlling the end point pH value to be 5.5-6, and then heating to 70-95 ℃.

And step 2, deeply purifying the manganese sulfate solution. Adding 0.5-1g/L BaS and 0.5-1g/L BaF into the solution₂Stirring for 1-2h to remove residual heavy metal ions and calcium and magnesium ions in the solution; then adding 3-5g/L aluminum sulfate or 1-2g/L commercial defluorinating agent, stirring for 1-2h, and standing for 1-2 h; and finally, performing precision filtration.

Example 1 preparation of Battery-grade manganese sulfate from pyrolusite leachate with corncob as biomass reducing agent

The pyrolusite treated in the example has the characteristics of high content of Ca and Mg, wherein the content of Ca is 8.51 percent, and the content of Mg is 6.77 percent.

The method comprises the following steps: the corncob is used as a reducing agent to perform reduction acid leaching in a sulfuric acid solution, and reduction leaching residue and acid leaching solution are obtained after filtration.

Firstly, adding 400-mesh (about 38um) corncobs and pyrolusite with the granularity less than 150um and the Mn grade of 22% into a 3mol/L sulfuric acid solution, wherein the mass ratio of the pyrolusite to the corncobs is 1:1, and the liquid-solid ratio of the solution is 5: 1; then, the solution is heated to 90 ℃ for reaction for 4 hours, and water is added for 1 time after the reaction for 1 hour in order to maintain the volume of the solution; filtering to obtain pickle liquor and leached residues after the reaction is finished;

secondly, the leached slag is placed in a high-temperature furnace isolated from air for heat treatment, the temperature is raised to 900 ℃ at the temperature rise rate of 10 ℃/min, then the temperature is kept for 3h, the positive pressure range in the high-temperature furnace is maintained to be 0.1-0.2MPa, then the heat treatment slag is added into the acid leaching solution maintained at the temperature of 60 ℃ for continuous stirring reaction, so that manganese elements in the heat-treated slag are fully dissolved out, meanwhile, the removal of organic matters in the acid leaching solution is realized, and the acid leaching solution after the removal of the organic matters is obtained by filtering after stirring reaction for 1 h.

Step two: removing impurities from the solution obtained in the step oneTo remove K, Na, Fe, Al, Pb, Co, Ni, Cd, As, Cu, Zn and other elements in the pickle liquor. The analysis shows that K in the pickle liquor⁺The concentration is 1.81g/L, Na⁺The concentration was 0.451g/L, and the total of the heavy metals such as Cu, Pb, and Zn in the pickle liquor was 45 mg/L. In addition, the Mn concentration was 43.97g/L, and the leaching rate of Mn in the first step was calculated to be 99.93%.

Step 1, using Mn (OH)₂Adjusting pH of the acid leaching solution to 1.5, and adding Fe into the solution system₂(SO₄)₃(40 times of the total amount of sodium ions and potassium ions in the solution), adding MnO₂(8 times the total amount of sodium and potassium ions in the solution); then, the solution was heated to 90 ℃ or higher, reacted for 1 hour and left to stand for 2 hours.

Step 2, continuing to use Mn (OH)₂And adjusting the pH value of the solution system to 5.5-6, then adding sodium ferometalate (15 times of the total weight of heavy metals in the solution) into the solution system, stirring for reaction for 1 hour, standing for 1 hour, and then filtering to obtain the manganese sulfate solution with the impurities except calcium and magnesium removed.

Step three: precipitating manganese by ammonia water and removing calcium and magnesium in manganese hydroxide.

Step 1, adding ammonia water to precipitate manganese. And D, adding ammonia water into the manganese sulfate solution obtained in the step two after impurities except calcium and magnesium are removed, so that manganese in the solution is precipitated in a manganese hydroxide form, the concentration of the added ammonia water is 8mol/L, the end-point pH value of the solution is 11 after the ammonia water is added, and then filtering to obtain a manganese hydroxide precipitate.

And 2, pulping the deionized water and the manganese hydroxide precipitate according to the liquid-solid ratio of 3:1, adding the formula 1-A (12 times of the total amount of calcium and magnesium) into the slurry, introducing carbon dioxide into the slurry until the pH value of the slurry reaches 7, stopping introducing the carbon dioxide, and filtering to remove the calcium and magnesium in the manganese hydroxide.

Dissolving manganese hydroxide in acid, deeply removing impurities from a manganese sulfate solution, and concentrating and crystallizing.

Step 1, adding the manganese hydroxide prepared in the step three after the calcium and magnesium are removed into a 50% sulfuric acid solution, controlling the end point pH value to be 5.8, and then heating to 80 ℃;

step 2, adding 0.5g/L of BaS and 0.5g/L of BaF into the solution₂Stirring for 1-2 h; then, adding 1g/L defluorinating agent prepared based on patent 201810659493.8, stirring for 1h, and standing for 1 h; and finally, performing precision filtration. Mn in manganese sulfate solution obtained in the process²⁺The concentration of (3) was 43.46g/L, and the calculated Mn yield was 98.77%.

And step 3, concentrating and crystallizing the manganese sulfate by adopting the known technologies such as MVR and the like to finally obtain the battery-grade manganese sulfate. The following table lists the impurity quality requirement standards of the battery-grade manganese sulfate and the detection results of the product prepared by the embodiment, and obviously, the impurity content of the product prepared by the technology of the invention is greatly lower than the quality requirement.

TABLE 1 content of impurities in manganese sulfate for Battery grade (ppm) in comparison with the product of this example

Element(s)

ΣFe

K

Na

Ca

Mg

Cu

Zn

Pb

Cd

As

F

Standard required content

<10

<50

<10

<5

<1

<700

The product of this example

3

5.5

6.5

10

9

1.5

1.2

-

5

Example 2

Compared with the embodiment 1, the treatment process of the first step is adjusted, and the different first step is as follows:

and carrying out reduction and acid leaching in a sulfuric acid solution by taking straw as a reducing agent, and filtering to obtain reduction leaching residues and an acid leaching solution.

Firstly, adding 400-mesh (about 38um) straw and pyrolusite with the granularity less than 150um and the Mn grade of 22% into a 3mol/L sulfuric acid solution, wherein the mass ratio of the pyrolusite to the corncob is 1:1, and the liquid-solid ratio of the solution is 5: 1; then, the solution is heated to 90 ℃ for reaction for 4 hours, and water is added for 1 time after the reaction for 1 hour in order to maintain the volume of the solution; filtering to obtain pickle liquor and leached residues after the reaction is finished;

secondly, heat treatment is carried out on the leached slag, the temperature is raised to 1000 ℃ at the temperature rise rate of 15 ℃/min, then the temperature is kept for 3h, the positive pressure range in the high-temperature furnace is maintained to be 0.1-0.2MPa, then the heat treatment slag is added into the acid leaching solution with the temperature maintained to be 50-70 ℃, the mixture is continuously stirred and reacted, so that manganese elements in the heat-treated slag are fully dissolved out, meanwhile, the removal of organic matters in the acid leaching solution is also realized, and after 2h of stirring and reaction, the filtrate obtained after the removal of the organic matters is the acid leaching solution.

The other operations and parameters were the same as in example 1.

The composition characteristics of the manganese sulfate solution obtained are shown in table 2:

TABLE 2 content of impurities in manganese sulfate for Battery grade (ppm) in comparison with the product of this example

Element(s)

ΣFe

K

Na

Ca

Mg

Cu

Zn

Pb

Cd

As

F

Standard required content

<10

<50

<10

<5

<1

<700

The product of this example

2.6

5.3

6.6

12

11

1.2

1.1

-

8

Example 3

Compared to example 1, the only difference is that the compound of formula 1 in step 2 of step three is regulated, and the step 2 of step three is distinguished:

and 2, pulping the deionized water and the manganese hydroxide precipitate according to the liquid-solid ratio of 3:1, adding the formula 1-B (15 times of the total amount of calcium and magnesium) into the slurry, introducing carbon dioxide into the slurry until the pH value of the slurry reaches 7, stopping introducing the carbon dioxide, and immediately filtering to remove the calcium and magnesium in the manganese hydroxide.

The other operations and parameters were the same as in example 1.

The composition of the resulting battery grade manganese sulfate solution is shown in Table 3.

TABLE 3 impurity requirement of Battery grade manganese sulfate and impurity content (ppm) of the product of this example

Element(s)

ΣFe

K

Na

Ca

Mg

Cu

Zn

Pb

Cd

As

F

Standard required content

<10

<50

<10

<5

<1

<700

The product of this example

2.8

4.3

6.4

11.7

12

1.6

1.3

-

5

Comparative example 1

Compared with the example 1, the difference is only that in the first step, no corncob is added, and Mn in the total leaching solution obtained in the first step²⁺Concentration of only17.92g/L, and the calculated leaching rate of Mn is only 40.72 percent. The leaching rate of manganese is obviously reduced.

Comparative example 2

The only difference compared to example 1 is that in step 2 of step three, the compound of formula 1-A is not added and the other steps and parameters are the same as in example 1.

The impurity element content of the manganese sulfate crystal product obtained by concentrating and crystallizing manganese sulfate by the MVR technology is shown in Table 4.

TABLE 4 impurity requirement of Battery grade manganese sulfate and impurity content (ppm) of the product of this example

Element(s)

ΣFe

K

Na

Ca

Mg

Cu

Zn

Pb

Cd

As

F

Standard required content

<10

<50

<10

<5

<1

<700

The product of this example

3.3

3.4

5.8

1127

907

3.2

1.5

-

9

Obviously, the elimination of the substance in formula 1 leads to too high contents of Ca and Mg in the final product, which cannot meet the requirement of manganese sulfate production. Mn in manganese sulfate solution finally obtained by the whole process²⁺Was 43.28g/L, and the calculated Mn recovery was 98.36%.

Comparative example 3

The only difference compared to example 1 is that in step 2 of step three, the compound of formula 1-A is replaced by the same amount of the compound of formula 2, and the other steps and parameters are the same as in example 1.

The impurity element content of the manganese sulfate crystal product obtained by concentrating and crystallizing manganese sulfate by the MVR technology is shown in Table 5.

TABLE 5 content of impurities in manganese sulfate for Battery grade (ppm) in comparison with the product of this example

Element(s)

ΣFe

K

Na

Ca

Mg

Cu

Zn

Pb

Cd

As

F

Standard required content

<10

<50

<10

<5

<1

<700

The product of this example

1.1

4.6

5.1

1141

885

4.4

2.3

-

8.5

Obviously, the elimination of the substance in formula 1 leads to too high contents of Ca and Mg in the final product, which cannot meet the requirement of manganese sulfate production. Mn in manganese sulfate solution finally obtained by the whole process²⁺The concentration of (D) was 43.22g/L, and the calculated recovery of Mn was 98.22%

Comparative example 4

Compared with the example 1, the difference is that in the step 2 of the third step, no carbon dioxide is introduced, and other steps and parameters are the same as those in the example 1.

The impurity element content of the manganese sulfate crystal product obtained by concentrating and crystallizing manganese sulfate by MVR technology is shown in Table 6.

TABLE 6 content of impurities in manganese sulfate for Battery grade (ppm) in comparison with the product of this example

Element(s)

ΣFe

K

Na

Ca

Mg

Cu

Zn

Pb

Cd

As

F

Standard required content

<10

<50

<10

<5

<1

<700

The product of this example

2.6

3.1

2.3

1324

1032

3.2

1.5

-

9.3

Obviously, CO is eliminated₂The content of Ca and Mg in the final product is too high, and the requirement of manganese sulfate production cannot be met. Mn in the manganese sulfate solution finally obtained²⁺Was 43.21g/L, and the calculated recovery rate of Mn was 98.20%.

Claims

1. a method of manganese oxide ore preparing battery grade manganese sulfate, is characterized in that, comprises the following steps:

Step (1): Second stage leaching

The manganese oxide ore, biomass and sulfuric acid are leached in the first stage, and then solid-liquid separation is performed to obtain the first stage leaching liquid and leaching residue;

The leaching residue is subjected to roasting treatment in an oxygen-free atmosphere, the obtained roasting material and the first-stage leachate are mixed to carry out the second-stage leaching, and the leachate is obtained by separation;

Step (2): impurity removal in the first stage

Add ferric sulfate and manganese-based oxidants to the leaching solution, heat up to carry out a first-stage precipitation reaction of precipitation of sodium and/or potassium, then add sulfide to the system, carry out a second-stage precipitation reaction of heavy metals, and then separate and obtain the first stage of impurity removal liquid;

Step (3): impurity removal in the second stage

The first stage of impurity removal liquid is subjected to manganese precipitation treatment to obtain manganese hydroxide precipitate, the precipitate and the compound of formula 1 are dispersed in a solvent to obtain a slurry, carbon dioxide is introduced into the slurry, and the second stage of impurity removal is carried out. Liquid separation obtains manganese hydroxide after removal of impurities;

Described R is H, alkyl group, carboxyl group or substituted alkyl group; Or R and described amino ring synthesize five-membered or six-membered ring group;

The M is H ⁺ , Na ⁺ , K ⁺ or NH ₄ ⁺ ;

Step (4): impurity removal in the third stage

The impurity-removed manganese hydroxide is dissolved in sulfuric acid, then BaS and BaF2 are added, and finally aluminum sulfate or a fluorine-removing agent is added, and after treatment, a battery-grade manganese sulfate solution is obtained by solid-liquid separation.

2. the manganese oxide ore as claimed in claim 1 prepares the method for battery grade manganese sulfate, it is characterized in that, described manganese oxide ore is at least one in pyrolusite, hard manganese ore and manganese ore;

Preferably, the particle size of the manganese oxide ore is controlled below 150um.

3. The method for preparing battery-grade manganese sulfate from manganese oxide ore as claimed in claim 1, wherein the biomass is a biomass waste comprising at least one of cellulose, hemicellulose or crude fiber;

Preferably, the biomass is at least one of straw, corn stover or corncob;

Preferably, the particle size of the biomass is controlled at 38um-74um;

Preferably, the mass ratio of manganese oxide ore to biomass waste is (1:1)～(3:1);

Preferably, the concentration of sulfuric acid is 1-3mol/L;

Preferably, in the first stage of leaching, the liquid-solid ratio is (3-10): 1 (mL/g);

Preferably, the temperature of the first leaching stage is 85-95°C;

Preferably, the time of the first leaching stage is 4-10h.

4. The method for preparing battery-grade manganese sulfate from manganese oxide ore as claimed in claim 1, wherein the roasting temperature is 850-1000°C;

Preferably, the roasting time is 2-4h;

Preferably, the temperature of the second leaching stage is 50-70°C;

Preferably, the time of the second leaching stage is 0.5-2h.

5. the method for preparing battery grade manganese sulfate from manganese oxide ore as claimed in claim 1, is characterized in that,

In step (2), the pH of the initial solution of a precipitation reaction is 1.5～2;

Preferably, manganese hydroxide is used to regulate and control the pH;

Preferably, the consumption of ferric sulfate is 40-50 times of the total amount of sodium ions and potassium ions in the leachate;

Preferably, the manganese-based oxidant is a manganese oxide with a positive tetravalent or higher valence, preferably manganese dioxide;

Preferably, the dosage of manganese-based oxidant is 8 to 10 times the total mass of sodium ions and potassium ions in the leachate;

Preferably, the temperature of a precipitation reaction is greater than or equal to 90°C; the reaction time is preferably 1-2h, and it is preferably left to stand for 1-2h after the reaction.

6. the method for preparing battery grade manganese sulfate from manganese oxide ore as claimed in claim 5, is characterized in that,

In step (2), the pH of the starting solution of the second-stage precipitation reaction is 5.5 to 6; preferably, manganese hydroxide is used to control the pH;

Preferably, the sulfide is sodium formamate;

Preferably, the consumption of sulfide is 15-20 times of the total mass of heavy metals in the solution system;

Preferably, the time of the second-stage precipitation reaction is 1-2h;

Preferably, after the second-stage precipitation reaction, the solid-liquid separation is performed after standing for 1-2 hours to obtain the first impurity-removing liquid.

7. the method for preparing battery grade manganese sulfate from manganese oxide ore as claimed in claim 1, is characterized in that, in step (3), the alkali that the manganese precipitation treatment stage adopts is ammoniacal liquor;

Preferably, the concentration of ammonia water is 6-10mol/L;

Preferably, the end point of the manganese precipitation reaction is 10-11.5;

Preferably, the alkyl group is a C1-C10 straight-chain or straight-chain alkyl group;

Preferably, the substituted alkyl group is a C1-C10 straight-chain or straight-chain alkyl group containing 1-3 substituents; the substituents are hydroxyl, C1-C4 alkoxy, aminoacyl, amide group, carboxyl group, mercapto group, C1-C4 alkylmercapto group, phenyl group, substituted phenyl group, five-membered heterocyclic aryl group, benzofive-membered heterocyclic aryl group, benzosix-membered heterocyclic aryl group or iminium group;

Preferably, the R is H, a C1-C4 alkyl group, a hydroxy-substituted C1-C4 alkyl group, or a phenyl-substituted C1-C4 alkyl group.

8. The method for preparing battery-grade manganese sulfate from manganese oxide ore according to claim 7, wherein the compound of formula 1 is not lower than the theoretical reaction amount, preferably 1-2 times the theoretical reaction molar amount;

Preferably, the solvent in the slurry is water, or a mixed solvent of water and an organic solvent, and the organic solvent can be, for example, a C1-C4 alcohol;

Preferably, in the slurry, the weight ratio of the solvent to the manganese hydroxide to be treated is 1-10:1;

Preferably, in the second-stage impurity removal process, the pH of the end point of introducing carbon dioxide is 6.5-7.5; more preferably, it is 6.8-7.2.

9. The method for preparing battery grade manganese sulfate from manganese oxide ore as claimed in claim 1, wherein in step (4), the concentration of sulfuric acid is 50-70%;

Preferably, the temperature of the acid-dissolving stage is 70-95°C;

Preferably, the pH of the acid-dissolved manganese sulfate solution is 5.5-6;

Preferably, the addition concentration of BaS is 0.5-1 g/L;

The added concentration of BaF2 is 0.5-1 g/L.

10. The method for preparing battery-grade manganese sulfate from manganese oxide ore as claimed in claim 9, wherein the application concentration of aluminum sulfate is 3-5 g/L; the application concentration of the fluoride remover is 1-2g/L.