阅读说明：本技术 从锂云母分离提取电池级碳酸锂及铷、铯盐的方法 (method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite ) 是由 李文宏 *** 沈毅 蔡伟平 于 2019-10-08 设计创作，主要内容包括：本发明就是要提供一种从锂云母分离提取电池级碳酸锂及铷、铯盐的方法,以锂云母为原料,采用酸化焙烧方法,其包括破碎、加料制浆,酸化浸出,拌料、干燥,酸化焙烧,水浸反应,两次冷却结晶,加碱中和分离石膏固渣,加除杂剂除杂,蒸发浓缩及制粗碳酸锂与铷、铯钒盐等,大幅降低锂云母提取的综合成本,大幅提升锂云母提取的综合竞争力；设备利用率高,环保三废排放小,生产成本低的制备电池级碳酸锂及铷、铯盐的方法。(The invention provides a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite, which takes the lepidolite as a raw material and adopts an acidification roasting method, wherein the acidification roasting method comprises the steps of crushing, feeding and pulping, acidification leaching, stirring, drying, acidification roasting, water leaching reaction, twice cooling and crystallization, adding alkali to neutralize and separate gypsum solid slag, adding an impurity removing agent to remove impurities, evaporating and concentrating, preparing crude lithium carbonate, rubidium, cesium and vanadium salt and the like, so that the comprehensive cost of lepidolite extraction is greatly reduced, and the comprehensive competitiveness of lepidolite extraction is greatly improved; the method for preparing the battery-grade lithium carbonate, rubidium and cesium salt has the advantages of high equipment utilization rate, small discharge of three environmental-friendly wastes and low production cost.)

1. a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite takes the lepidolite as a raw material, adopts various circulating modes of acidification roasting, leachate circulation and lithium extraction mother liquor circulation, controls the concentration of potassium, sodium, rubidium and cesium in mother liquor corresponding to each working procedure, and is combined with a crystallization phase through evaporation concentration, and is characterized by specifically comprising the following steps:

1) crushing, adding materials and pulping, namely crushing lepidolite into powder, sealing and stacking, and conveying the powder or prepared slurry into a reaction kettle device to obtain pretreated lepidolite powder;

2) acidifying and leaching, namely adding pretreated lithium mica powder, concentrated sulfuric acid and water into a reaction kettle device together, stirring and mixing uniformly to obtain a lithium mica acid water mixture, heating steam under the normal pressure environment condition for 3-6 hours to obtain sulfate solution mother liquor 1 containing lithium, potassium, sodium, rubidium and cesium, hydrogen fluoride and fluoride generated by an acidifying reaction, acid steam and residual acid, and cooling the sulfate solution mother liquor 1 containing lithium, potassium, sodium, rubidium and cesium to obtain an acidified leaching material; hydrogen fluoride and fluoride generated by the acidification reaction and acid steam enter a tail gas recovery treatment system for treatment; neutralizing and filter-pressing the hydrogen fluoride and fluoride generated by the acidification reaction, acid steam and residual acid to obtain filtrate and filter residue 1, returning the filtrate to the water supplementing process of the acidification leaching process, and recycling or externally selling the filter residue 1;

3) Mixing and drying, namely adding water into the acidified leaching material obtained in the step 2) to prepare acidified leaching mixed solution, adding dried silica sand into the acidified leaching mixed solution, mixing and continuously stirring to prepare solid-liquid mixed solution, fully stirring and mixing the solid-liquid mixed solution, and then placing the solid-liquid mixed solution into a drying device for drying to obtain dried mixed material; the water vapor and tail gas generated during drying are treated by a tail gas recovery treatment system and sprayed and then discharged after reaching the standard;

4) acidizing and roasting, namely placing the dried and mixed material obtained in the step 3) into a roasting kiln for roasting treatment, and controlling the roasting treatment temperature to be 300-900 ℃ to obtain a roasted material; after waste gas generated by roasting enters a tail gas recovery treatment system for treatment, the waste gas is discharged after reaching the standard;

5) Water leaching reaction, namely adding water into the roasted material obtained in the step 4), stirring and mixing to obtain solid-liquid mixture, and controlling the solid-liquid mass ratio of the roasted material to the water to be 1: 1.1-1.3, carrying out water leaching treatment to obtain a solid-liquid mixed water solution, filtering and separating the solid-liquid mixed water solution after the water leaching treatment is finished to obtain a mother solution 2 and a filter residue 2, washing the filter residue 2 and drying to obtain dry silica sand;

6) primary cooling crystallization, namely placing the mother liquor 1 and the mother liquor 2 in a cooling crystallization device, and adopting circulating frozen brine for cooling treatment to obtain primary cooling crystallization under the condition of continuous stirring to obtain a mixed solution of precipitated aluminum rubidium alum and aluminum cesium alum; filtering and separating the mixed solution of aluminum, rubidium, alum and aluminum, cesium and alum to obtain a mother solution 3, a rubidium, cesium and potassium mixture of rubidium, cesium and alum and potassium, sodium and alum;

7) performing secondary cooling crystallization to prepare potassium sodium alum, adding a secondary catalytic crystallization agent into the mother liquor 3 obtained in the step 6), performing cooling secondary cooling crystallization treatment to obtain a mixed solution of aluminum sodium alum and aluminum potassium alum, and filtering and separating the mixed solution of aluminum sodium alum and aluminum potassium alum to obtain a mother liquor 4 and potassium sodium alum;

8) adding alkali to neutralize and separate gypsum solid residue, adding lime milk into the mother liquor 4 obtained in the step 7), then adding hydrogen peroxide solution to obtain a mother liquor mixed solution, generating a large amount of precipitates by controlling the pH value of the mother liquor mixed solution, and performing filter pressing and separation to obtain gypsum solid residue and a mother liquor 5;

9) Adding an impurity removal catalyst to remove impurities, adding the impurity removal catalyst into the mother liquor 5 obtained in the step 8) to remove impurities, filtering and separating to obtain solid gypsum residues and a mother liquor 6; returning the gypsum solid slag to the step 2), wherein the neutralization process is a neutralization addition raw material;

10) Evaporating and concentrating, namely putting the mother liquor 6 into an MVR high-efficiency evaporator, performing high-temperature evaporating and concentrating treatment to obtain an evaporated and concentrated solution, controlling the concentration of Li ions in the evaporated and concentrated solution to be 14-33g/L to obtain a concentrated liquor 7, and performing lithium precipitation and agitation washing on the concentrated liquor 7; recovering the condensed water generated by the high-temperature evaporation and concentration treatment into the washing water for preparing the sodium carbonate and the lithium carbonate;

11) Separating to prepare crude lithium carbonate, adding carbonate solution into the concentrated solution mother liquor 7, carrying out lithium precipitation reaction, obtaining crude lithium carbonate and mother liquor 8 after lithium precipitation, and washing the crude lithium carbonate by using heated water, wherein the mother liquor 8 after lithium precipitation is evaporated and concentrated by an evaporator until the concentration of Li ₂ O in the solution is 15-30g/L, carrying out centrifugal filtration separation to obtain solid and centrifugal separation solution, drying the solid to obtain anhydrous sodium sulfate solid, and carrying out secondary lithium precipitation on the centrifugal separation solution to obtain industrial-grade lithium carbonate which is crude lithium carbonate;

12) Purifying the crude lithium carbonate to prepare battery-grade lithium carbonate, adding water into the crude lithium carbonate, fully stirring and mixing to prepare a crude lithium carbonate mixed aqueous solution, introducing CO ₂ gas into the crude lithium carbonate mixed aqueous solution for dissolving, after the crude lithium carbonate is fully dissolved, decomposing under the heating condition, removing impurities, filtering and separating, drying filter residues by a dryer to obtain the battery-grade lithium carbonate, and recovering filtrate;

13) Preparing rubidium-cesium salt, namely performing back extraction on the rubidium-cesium-alum prepared in the step 6) and a rubidium-cesium-potassium mixture of potassium-sodium alum by using corresponding acid, and preparing a high-purity cesium salt product and a corresponding raffinate; and performing acid stripping by using the raffinate as a raw material to prepare a high-purity rubidium salt product.

2. The method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite according to claim 1, wherein the acidification leaching in the step 2) is performed by controlling the mass ratio of pretreated lepidolite powder to concentrated sulfuric acid to water to be 1: 0.8-1.05: 0.8-1.1; controlling the steam heating reaction temperature to be 80-150 ℃; the temperature reduction treatment is to control the temperature of the temperature reduction treatment to be 80-100 ℃; the neutralization is to add lime milk or lime milk made of gypsum solid residue into the residual acid for neutralization treatment, and the neutralization treatment is controlled until the pH value is 6-9.

3. the method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite according to claim 1, wherein the step 3) of stirring and drying is to control the solid-liquid ratio of the solid-liquid mixed liquid to be 0.3: 1-0.5: 1, controlling the drying to be drying by adopting a rotary drying kiln device, controlling the drying time to be 0.4-0.6h and controlling the drying temperature to be 100-150 ℃; and controlling the water vapor generated during drying and the tail gas generated by combustion to enter a tail gas treatment system of the rotary drying kiln, firstly spraying water to prepare dilute sulfuric acid with the concentration of 30-38Wt%, returning the dilute sulfuric acid to the acid leaching process for use, and discharging the sprayed tail gas after the tail gas is subjected to secondary treatment by soda lime absorption to reach the standard.

4. the method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite according to claim 1, wherein the step 5) is characterized in that water immersion reaction is carried out, the water immersion treatment time is controlled to be 1-3h, and the water immersion treatment temperature is 70-95 ℃; and (3) returning the silica sand to be used as the raw material in the steps of stirring and drying in the step 3).

5. The method as claimed in claim 1, wherein the step 6) of primary cooling crystallization is carried out at a temperature of 10-65 ℃ for 3-6 hours.

6. The method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite according to claim 1, wherein in step 7), secondary cooling crystallization is carried out, wherein the temperature of the secondary cooling crystallization is controlled to be-15-25 ℃, and the time is 3-6 hours; the secondary catalytic crystallization agent is a mixed solution of a plurality of or all component solutions of aminobutyric acid, hydrochloric acid, liquid ammonia, calcium chloride, magnesium chloride, sodium phosphate and sodium nitrate.

7. the method as claimed in claim 1, wherein the step 8) of adding alkali to neutralize and separate gypsum solid residue is to add 30-35wt% of lime milk and then 20-30wt% of hydrogen peroxide solution into mother liquor 4 at-15-25 ℃.

8. the method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite according to claim 1, wherein in the step 9), an impurity removing agent is added for removing impurities, and the impurity removing agent is a mixed solution of sulfuric acid, calcium chloride, magnesium chloride, sodium chloride and a sodium phosphate solution; the gypsum solid residue obtained by separation is calcium oxide or calcium hydroxide.

9. The method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite according to claim 1, wherein step 11) is to separate crude lithium carbonate, add sodium carbonate or potassium carbonate solution to the concentrated solution mother liquor 7, and control the reaction temperature of lithium precipitation to be 80-95 ℃; the time is 40-100 minutes.

The technical field is as follows: the invention relates to an extraction method for separating and extracting refined lithium carbonate and rubidium and cesium from a lepidolite raw material, in particular to a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite.

Background art:

The lithium battery new energy is one of national key support and development energy industries; lithium carbonate is used as an important basic raw material for the development of new energy of lithium batteries, and the production and demand of the lithium carbonate are increasingly large, and the price of the lithium carbonate is also increasingly high.

Lepidolite is an important mineral resource and contains abundant rare metal materials, lithium, sodium, potassium, rubidium, cesium, aluminum and the like. With the increasing shortage of world energy, developing and utilizing new energy is a common topic in the world and is more and more emphasized by various countries; lithium and salts thereof such as lithium carbonate and lithium sulfate are basic raw material products of the lithium new energy industry, and since lepidolite contains lithium metal which is a basic material of the lithium new energy industry, the development and application of lepidolite become a popular problem at present.

china has the largest tantalum-niobium-lithium ore in Asia at present, the tantalum-niobium-lithium resource is rich, the content of lithium dioxide in lepidolite reaches 4.5 percent, and the method has the advantage condition of extracting lithium carbonate resource. Meanwhile, the lithium mica powder also contains abundant rubidium, cesium, potassium and other resources, so that the lithium carbonate, the rubidium, the cesium, the potassium and the like are extracted by taking the lepidolite as a raw material, and the lithium mica powder has a wide market prospect and good economic benefits.

from the existing production process, the comprehensive extraction of resources such as lithium carbonate, rubidium, cesium and potassium is not ideal, the comprehensive production benefit is not high, the input-output ratio is insufficient, and the industrial production is difficult to realize. How to realize the technical production of the lepidolite all-element separation and extraction process, and the other process technologies only can implement the production to lithium carbonate, a mixture and the like, how to realize the essential promotion of the technical process, how to realize the all-element industrialized extraction of lithium, rubidium, cesium and potassium in the lepidolite concentrate, realize the full resource utilization, and have great economic benefit and deep environmental benefit: firstly, how to realize the separation and extraction of high-purity rubidium salt and cesium salt by 1 time of tailings generated after lithium extraction can bring high additional economic benefit, greatly reduce the comprehensive cost of lepidolite extraction and greatly improve the comprehensive competitiveness of lepidolite extraction;

secondly, how to realize the actual utilization of rubidium and cesium in the lepidolite raw material, thereby realizing the separation, extraction and utilization of the downstream rubidium and cesium of the secondary tailings for separating and extracting potassium; thirdly, only by separating lithium, rubidium, cesium and potassium in the lepidolite and utilizing all resources, the environment-friendly discharge of 0 can be realized in the true sense of the lepidolite raw material, and the comprehensive development, utilization and development of the lepidolite raw material ore are promoted; reducing the large pressure on the environment.

The invention content is as follows:

the invention provides a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite, which takes the lepidolite as a raw material and adopts an acidification roasting method, wherein the acidification roasting method comprises the steps of crushing, feeding and pulping, acidification leaching, stirring, drying, acidification roasting, water leaching reaction, twice cooling and crystallization, adding alkali to neutralize and separate gypsum solid slag, adding an impurity removing agent to remove impurities, evaporating and concentrating, preparing crude lithium carbonate, rubidium, cesium and vanadium salt and the like, so that the comprehensive cost of lepidolite extraction is greatly reduced, and the comprehensive competitiveness of lepidolite extraction is greatly improved; the method for preparing the battery-grade lithium carbonate, rubidium and cesium salt has the advantages of high equipment utilization rate, small discharge of three environmental-friendly wastes and low production cost.

the invention discloses a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite, which uses the lepidolite as a raw material, adopts multiple circulation modes of acidification roasting, leachate circulation and lithium extraction mother liquor circulation, controls the concentration of potassium, sodium, rubidium and cesium in the mother liquor corresponding to each working procedure, and adopts a method of combination of evaporation concentration and crystal phase, and the method specifically comprises the following steps:

1) crushing, adding materials and pulping, namely crushing lepidolite into powder, sealing and stacking, and conveying the powder or prepared slurry into a reaction kettle device to obtain pretreated lepidolite powder;

2) Acidifying and leaching, namely adding pretreated lithium mica powder, concentrated sulfuric acid and water into a reaction kettle device together, stirring and mixing uniformly to obtain a lithium mica acid water mixture, heating steam under the normal pressure environment condition for 3-6 hours to obtain sulfate solution mother liquor 1 containing lithium, potassium, sodium, rubidium and cesium, hydrogen fluoride and fluoride generated by an acidifying reaction, acid steam and residual acid, and cooling the sulfate solution mother liquor 1 containing lithium, potassium, sodium, rubidium and cesium to obtain an acidified leaching material; hydrogen fluoride and fluoride generated by the acidification reaction and acid steam enter a tail gas recovery treatment system for treatment; neutralizing and filter-pressing the hydrogen fluoride and fluoride generated by the acidification reaction, acid steam and residual acid to obtain filtrate and filter residue 1, returning the filtrate to the water supplementing process of the acidification leaching process, and recycling or externally selling the filter residue 1;

3) mixing and drying, namely adding water into the acidified leaching material obtained in the step 2) to prepare acidified leaching mixed solution, adding dried silica sand into the acidified leaching mixed solution, mixing and continuously stirring to prepare solid-liquid mixed solution, fully stirring and mixing the solid-liquid mixed solution, and then placing the solid-liquid mixed solution into a drying device for drying to obtain dried mixed material; the water vapor and tail gas generated during drying are treated by a tail gas recovery treatment system and sprayed and then discharged after reaching the standard;

4) Acidizing and roasting, namely placing the dried and mixed material obtained in the step 3) into a roasting kiln for roasting treatment, and controlling the roasting treatment temperature to be 300-900 ℃ to obtain a roasted material; after waste gas generated by roasting enters a tail gas recovery treatment system for treatment, the waste gas is discharged after reaching the standard;

5) Water leaching reaction, namely adding water into the roasted material obtained in the step 4), stirring and mixing to obtain solid-liquid mixture, and controlling the solid-liquid mass ratio of the roasted material to the water to be 1: 1.1-1.3, carrying out water leaching treatment to obtain a solid-liquid mixed water solution, filtering and separating the solid-liquid mixed water solution after the water leaching treatment is finished to obtain a mother solution 2 and a filter residue 2, washing the filter residue 2 and drying to obtain dry silica sand;

6) primary cooling crystallization, namely placing the mother liquor 1 and the mother liquor 2 in a cooling crystallization device, and adopting circulating frozen brine for cooling treatment to obtain primary cooling crystallization under the condition of continuous stirring to obtain a mixed solution of precipitated aluminum rubidium alum and aluminum cesium alum; filtering and separating the mixed solution of aluminum, rubidium, alum and aluminum, cesium and alum to obtain a mother solution 3, a rubidium, cesium and alum mixture and a rubidium, cesium and potassium mixture of potassium, sodium and alum;

7) performing secondary cooling crystallization to prepare potassium sodium alum, adding a secondary catalytic crystallization agent into the mother liquor 3 obtained in the step 6), performing cooling secondary cooling crystallization treatment to obtain a mixed solution of aluminum sodium alum and aluminum potassium alum, and filtering and separating the mixed solution of aluminum sodium alum and aluminum potassium alum to obtain a mother liquor 4 and potassium sodium alum;

8) adding alkali to neutralize and separate gypsum solid residue, adding lime milk into the mother liquor 4 obtained in the step 7), then adding hydrogen peroxide solution to obtain a mother liquor mixed solution, generating a large amount of precipitates by controlling the pH value of the mother liquor mixed solution, and performing filter pressing and separation to obtain gypsum solid residue and a mother liquor 5;

9) adding an impurity removal catalyst to remove impurities, adding the impurity removal catalyst into the mother liquor 5 obtained in the step 8) to remove impurities, filtering and separating to obtain solid gypsum residues and a mother liquor 6; returning the gypsum solid slag to the step 2), wherein the neutralization process is a neutralization addition raw material;

10) Evaporating and concentrating, namely putting the mother liquor 6 into an MVR high-efficiency evaporator, performing high-temperature evaporating and concentrating treatment to obtain an evaporated and concentrated solution, controlling the concentration of Li ions in the evaporated and concentrated solution to be 14-33g/L to obtain a concentrated mother liquor 7, and performing lithium precipitation and agitation washing on the concentrated mother liquor 7; recovering the condensed water generated by the high-temperature evaporation and concentration treatment into the washing water for preparing the sodium carbonate and the lithium carbonate;

11) Separating to prepare crude lithium carbonate, adding carbonate solution into the concentrated solution mother liquor 7, carrying out lithium precipitation reaction, obtaining crude lithium carbonate and mother liquor 8 after lithium precipitation, and washing the crude lithium carbonate by using heated water, wherein the mother liquor 8 after lithium precipitation is evaporated and concentrated by an evaporator until the concentration of Li ₂ O in the solution is 15-30g/L, carrying out centrifugal filtration separation to obtain solid and centrifugal separation solution, drying the solid to obtain anhydrous sodium sulfate solid, and carrying out secondary lithium precipitation on the centrifugal separation solution to obtain industrial-grade lithium carbonate which is crude lithium carbonate;

12) Purifying the crude lithium carbonate to prepare battery-grade lithium carbonate, adding water into the crude lithium carbonate, fully stirring and mixing to prepare a crude lithium carbonate mixed aqueous solution, introducing CO ₂ gas into the crude lithium carbonate mixed aqueous solution for dissolving, after the crude lithium carbonate is fully dissolved, decomposing under the heating condition, removing impurities, filtering and separating, drying filter residues by a dryer to obtain the battery-grade lithium carbonate, and recovering filtrate;

13) preparing rubidium-cesium salt, namely performing back extraction on the rubidium-cesium-alum prepared in the step 6) and a rubidium-cesium-potassium mixture of potassium-sodium alum by using corresponding acid, and preparing a high-purity cesium salt product and a corresponding raffinate; and performing acid stripping by using the raffinate as a raw material to prepare a high-purity rubidium salt product.

preferably, in the step 2), the acidification leaching is performed, wherein the mass ratio of pretreated lithium mica powder to concentrated sulfuric acid to water is controlled to be 1: 0.8-1.05: 0.8-1.1; controlling the steam heating reaction temperature to be 80-150 ℃; the temperature reduction treatment is to control the temperature of the temperature reduction treatment to be 80-100 ℃; the neutralization is to add lime milk or lime milk made of gypsum solid residue into the residual acid for neutralization treatment, and the pH value of the neutralization treatment is controlled to be 6-9.

Preferably, in the step 3), the material mixing and drying are carried out, wherein the solid-liquid ratio of the solid-liquid mixed solution is controlled to be 0.3: 1-0.5: 1, controlling the drying to be drying by adopting a rotary drying kiln device, controlling the drying time to be 0.4-0.6h and controlling the drying temperature to be 100-150 ℃; and controlling the water vapor generated during drying and the tail gas generated by combustion to enter a tail gas treatment system of the rotary drying kiln, firstly spraying water to prepare dilute sulfuric acid with the concentration of 30-38Wt%, returning the dilute sulfuric acid to the acid leaching process for use, and discharging the sprayed tail gas after the tail gas is subjected to secondary treatment by soda lime absorption to reach the standard.

the method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite comprises the step 5) of water leaching reaction, wherein the time of water leaching treatment is controlled to be 1-3 hours, and the temperature of the water leaching treatment is 70-95 ℃; and (3) returning the silica sand to be used as the raw material in the steps of stirring and drying in the step 3).

The method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite comprises the step 6) of primary cooling crystallization, wherein the temperature of the primary cooling crystallization is controlled to be 10-65 ℃ for crystallization, and the cooling crystallization time is controlled to be 3-6 hours.

the method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite comprises the following steps of 7) carrying out secondary cooling crystallization, wherein the temperature of the secondary cooling crystallization is controlled to be-15-25 ℃, and the time is 3-6 hours; the secondary catalytic crystallization agent is a mixed solution of multiple or all component solutions of aminobutyric acid, hydrochloric acid, liquid ammonia, calcium chloride, magnesium chloride, sodium phosphate and sodium nitrate.

further, adding alkali to neutralize and separate gypsum solid residue in the step 8), namely adding 30-35wt% of lime milk into the mother liquor 4 at the temperature of-15-25 ℃, and then adding 20-30wt% of hydrogen peroxide solution.

preferably, in the step 9), an impurity removing agent is added for removing impurities, wherein the impurity removing agent is a mixed solution of sulfuric acid, calcium chloride, magnesium chloride, sodium chloride and a sodium phosphate solution; the gypsum solid residue obtained by separation is calcium oxide or calcium hydroxide.

further, separating crude lithium carbonate in the step 11), adding a sodium carbonate or potassium carbonate solution into the concentrated solution mother liquor 7, and controlling the reaction temperature of lithium precipitation to be 80-95 ℃; the time is 40-100 minutes.

The invention relates to a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite, which takes the lepidolite as a raw material and adopts the ten working procedures of crushing, feeding and pulping, acidifying and leaching, stirring, drying, acidifying and roasting, water leaching reaction, cooling and crystallization for two times, adding alkali to neutralize and separate gypsum solid slag, adding an impurity removing agent to remove impurities, evaporating and concentrating, preparing crude lithium carbonate, rubidium and cesium vanadium salt and the like. In the process of extracting battery-grade lithium carbonate, rubidium and cesium salts, wherein in the process of secondary cooling crystallization, a mixed solution of partial or all components of a secondary catalytic crystallization agent, namely aminobutyric acid, hydrochloric acid, liquid ammonia, calcium chloride, magnesium chloride, sodium phosphate and sodium nitrate, is added into the mother liquor 3. The mixed solution of partial components or solutions of a plurality of components refers to the mixed solution of any more than two of the above components in any proportion, or the mixed solution of all the above components in any proportion; the addition proportion of the components of the catalytic crystallization agent is to control the concentration of lithium ions in the mother liquor 4 obtained in the subsequent steps and the removed impurities to meet the extraction conditions and requirements, so that the content of the lithium ions in the prepared mother liquor 4 is improved, the content of the impurities in the solution is further reduced, and the potassium sodium alum can be rapidly crystallized and precipitated. Adding a mixed solution of sulfuric acid, calcium chloride, magnesium chloride, sodium chloride and sodium phosphate solution as an impurity removal catalyst in the impurity removal process; the catalyst does not contain heavy metal salt, and the adding amount of each component of the catalyst is the same as the adding amount of each component of the secondary catalytic crystallization agent; the aim is to remove impurities from the mother liquor 5 more cleanly. The method has the advantages that technical production of the lepidolite all-element separation and extraction process is realized, compared with the prior art, the production can be implemented to a lithium carbonate + rubidium-cesium-potassium mixture, the essential improvement of the technical process is realized, meanwhile, the all-element industrial extraction of lithium, rubidium, cesium and potassium in lepidolite concentrate is realized, the full resource utilization is realized, and the method has great economic benefit and deep environmental benefit, which is mainly reflected in that firstly, high-purity rubidium salt and cesium salt separated and extracted by 1 time of tailings generated after lithium extraction are realized, the high-additional economic benefit can be brought, meanwhile, the comprehensive cost of lepidolite extraction is greatly reduced, and the comprehensive competitiveness of lepidolite extraction is greatly improved; secondly, the practical utilization of rubidium and cesium in the lepidolite raw material is realized, so that the downstream separation, extraction and utilization of rubidium and cesium of the potassium extracted by secondary tailings are realized; thirdly, only lithium, rubidium, cesium and potassium in the lepidolite are separated, full resource utilization is really comprehensive utilization, and waste gas, tail gas and the like enter a recovery treatment system for treatment, namely a tail gas treatment system for treatment and then are discharged, so that environment-friendly 0 discharge is really realized for the lepidolite raw material, and comprehensive extraction, utilization and development of the lepidolite raw material ore are promoted; reducing the pressure on the environment. The lithium content in the leaching solution is greatly improved, and the leaching residue is common solid waste residue because of water leaching, and can be used as a raw material of building materials. Meanwhile, the production method has the advantages of stable operation process, short production period, high equipment utilization rate, low production cost, more raw materials recycling, less three-waste discharge and small influence on environment.

The invention relates to a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salts from lepidolite, which adopts a water leaching acidification roasting method, wherein leaching residues are common solid waste residues and can be used as raw materials of building materials, and the production cost is greatly reduced.

The invention discloses a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite, which mainly comprises the following process flows of lepidolite crushing, pulping → acidification leaching → filtration separation → material mixing drying → acidification roasting → water leaching → filtration → cooling crystallization → filtration separation → secondary cooling crystallization → rubidium, cesium and alum → mother liquor evaporation → impurity removal → lithium carbonate preparation and rubidium and cesium salt preparation.

the purity of the battery-grade lithium carbonate prepared by the method of the invention is over 99.5 percent through the detection of relevant departments, and the quality indexes of the product are shown in the following table 1 through the detection of various relevant technical indexes, and the quality index of the product is shown in the table 1

description of the drawings: 1. the water content in the product is less than or equal to 0.40 percent;

2. the average grain diameter of the product is less than or equal to 6 mu m; d50 is more than or equal to 2 mu m and less than or equal to 4 mu m; d90 is more than or equal to 9 mu m and less than or equal to 12 mu m;

3. the battery grade lithium carbonate is white powder and has no visible impurities.

table 2 shows the quality index of industrial-grade lithium carbonate prepared by the method of the invention,

table 2 quality testing indexes

It shows that most industrial products can reach the general first grade and general second grade, and a small amount of industrial products can reach the general special grade standard.

the quality indexes of the 4N rubidium carbonate product prepared by the method are shown in the following table 3 after detection,

TABLE 3 quality index

Description of the drawings: 1. other 4N rubidium salt chemical compositions refer to 4N rubidium carbonate.

the quality indexes of the 4N cesium carbonate product prepared by the method are shown in the following table 4;

TABLE 4 quality index

Description of the drawings: 1. other 4N cesium salt chemistries were referenced to 4N cesium carbonate.

the specific implementation mode is as follows:

the present invention will be described in further detail with reference to specific examples.

the invention discloses a method for separating and extracting battery-grade lithium carbonate, rubidium and cesium salt from lepidolite, which takes the lepidolite as a raw material and adopts an acidification roasting method, and comprises the following steps:

1) crushing, adding materials and pulping, namely crushing lepidolite into powder, sealing and stacking, and conveying the powder or prepared slurry into a reaction kettle device to obtain pretreated lepidolite powder;

2) Acidifying and leaching, namely adding pretreated lithium mica powder, concentrated sulfuric acid and water into a reaction kettle device together, stirring and mixing uniformly to obtain a lithium mica acid water mixture, heating steam under the normal pressure environment condition for 3-6 hours to obtain sulfate solution mother liquor 1 containing lithium, potassium, sodium, rubidium and cesium, hydrogen fluoride and fluoride generated by an acidifying reaction, acid steam and residual acid, and cooling the sulfate solution mother liquor 1 containing lithium, potassium, sodium, rubidium and cesium to obtain an acidified leaching material; hydrogen fluoride and fluoride generated by the acidification reaction and acid steam enter a tail gas recovery treatment system for treatment; neutralizing and filter-pressing the residual acid to obtain filtrate and filter residue 1, returning the filtrate to the acidification leaching process for water supplement, and recycling or externally selling the filter residue 1; the mass ratio of the lithium mica powder to the concentrated sulfuric acid to the water is 1: 0.8-1.05: 0.8-1.1; controlling the steam heating reaction temperature to be 80-150 ℃; the temperature reduction treatment is to control the temperature of the temperature reduction treatment to be 80-100 ℃; the neutralization is to add lime milk into the residual acid for neutralization treatment, and the pH value during the neutralization treatment is controlled to be 6-9;

3) stirring and drying, namely adding water and silica sand into the acidified leaching material obtained in the step 2), mixing, continuously stirring to prepare a solid-liquid mixed solution, fully stirring and mixing the solid-liquid mixed solution, and drying in a drying device to obtain a dried stirring material; the water vapor and tail gas generated in drying are treated by a tail gas recovery treatment system and sprayed and then discharged after reaching the standard, and the drying device is a rotary drying kiln for drying; controlling the solid-liquid ratio of the solid-liquid mixed liquid to be 0.3: 1-0.5: 1, controlling the drying to be drying by adopting a rotary drying kiln device, controlling the drying time to be 0.4-0.6h and controlling the drying temperature to be 100-150 ℃;

4) acidizing and roasting, namely placing the dried and mixed material obtained in the step 3) into a roasting kiln for roasting treatment, and controlling the roasting treatment temperature to be 300-900 ℃ to obtain a roasted material; after waste gas generated by roasting enters a tail gas recovery treatment system for treatment, the waste gas is discharged after reaching the standard;

5) performing water leaching reaction, namely adding water into the roasted material obtained in the step 4), stirring and mixing to prepare a solid-liquid mixed solution, and controlling the solid-liquid mass ratio of the roasted material to the water to be 1: 1.1-1.3, carrying out water leaching treatment to obtain a solid-liquid mixed water solution, filtering and separating the solid-liquid mixed water solution after the water leaching treatment is finished to obtain a mother solution 2 and a filter residue 2, washing the filter residue 2 and drying to obtain silica sand; controlling the time of water immersion treatment to be 1-3h, and controlling the temperature of the water immersion treatment to be 70-95 ℃; and (3) returning the silica sand to be used as the raw material in the steps of stirring and drying in the step 3).

6) primary cooling crystallization, namely placing the mother liquor 1 and the mother liquor 2 in a cooling crystallization device, adopting circulating frozen brine for cooling treatment to be primary cooling crystallization under the condition of continuous stirring, controlling the temperature of the primary cooling crystallization to be 10-65 ℃ for crystallization, and controlling the cooling crystallization time to be 3-6 hours; obtaining a mixed solution of aluminum rubidium alum and aluminum cesium alum; filtering and separating the mixed solution of aluminum, rubidium, alum and aluminum, cesium and alum to obtain a mother solution 3, a rubidium, cesium and alum mixture and a rubidium, cesium and potassium mixture of potassium, sodium and alum;

7) secondary cooling crystallization to prepare potassium sodium alum, namely adding a secondary catalytic crystallization agent into the mother liquor 3 obtained in the step 6), and performing cooling secondary cooling crystallization treatment, wherein the temperature of the secondary cooling crystallization is controlled to be-15-25 ℃, and the time is 3-6 hours; the secondary catalytic crystallization agent is a mixed solution of partial or all component solutions of aminobutyric acid, hydrochloric acid, liquid ammonia, calcium chloride, magnesium chloride, sodium phosphate and sodium nitrate; the addition amount and the addition proportion of the components of the secondary catalytic crystallization agent enable the generated alunite and the alunite to be corresponding, enable the concentration of lithium ions in the mother liquor 4 to reach the corresponding quality requirement in the next separation to be corresponding, obtain a mixed solution of the alunite and the alunite, and filter and separate the mixed solution to obtain the mother liquor 4 and the potassium alum;

8) Adding alkali to neutralize and separate gypsum solid residue, adding 30-35wt% of lime milk into the mother liquor 4 in the step 7) at the temperature of-15-25 ℃, and then adding 20-30wt% of hydrogen peroxide solution; obtaining a mother liquor mixed solution, generating a large amount of precipitates by controlling the pH value of the mother liquor mixed solution, and performing filter pressing and separation to obtain gypsum solid residues and a mother liquor 5;

9) adding an impurity removal catalyst to remove impurities, and adding the impurity removal catalyst into the mother liquor 5 obtained in the step 8) to perform impurity removal treatment, wherein the impurity removal catalyst is a mixed solution of sulfuric acid, calcium chloride, magnesium chloride, sodium chloride and a sodium phosphate solution; filtering and separating to obtain solid residues of calcium oxide or calcium hydroxide and mother liquor 6; the addition amount of each component of the mixed solution of sulfuric acid, calcium chloride, magnesium chloride, sodium chloride and sodium phosphate solution of the same impurity removal catalyst corresponds to the concentration of Li ions in the concentrated solution when each component is added for evaporation and concentration;

10) evaporating and concentrating, namely putting the mother liquor 6 into an MVR high-efficiency evaporator, performing high-temperature evaporating and concentrating treatment to obtain an evaporated and concentrated solution, controlling the concentration of Li ions in the evaporated and concentrated solution to be 14-33g/L to obtain a concentrated mother liquor 7, and performing lithium precipitation and agitation washing on the concentrated mother liquor 7; recovering the condensed water generated by the high-temperature evaporation and concentration treatment into the washing water for preparing the sodium carbonate and the lithium carbonate;

11) separating to prepare crude lithium carbonate, adding carbonate solution into the concentrated solution mother liquor 7, carrying out lithium precipitation reaction, obtaining crude lithium carbonate and mother liquor 8 after lithium precipitation, and washing the crude lithium carbonate by using heated water, wherein the mother liquor 8 after lithium precipitation is evaporated and concentrated by an evaporator until the concentration of Li ₂ O in the solution is 15-30g/L, carrying out centrifugal filtration separation to obtain solid and centrifugal separation solution, drying the solid to obtain anhydrous sodium sulfate solid, and carrying out secondary lithium precipitation on the centrifugal separation solution to obtain industrial-grade lithium carbonate which is crude lithium carbonate;

12) purifying the crude lithium carbonate to prepare battery-grade lithium carbonate, adding water into the crude lithium carbonate, fully stirring and mixing to prepare a crude lithium carbonate mixed aqueous solution, introducing CO ₂ gas into the crude lithium carbonate mixed aqueous solution for dissolving, decomposing under the heating condition after the crude lithium carbonate is fully dissolved, removing impurities, filtering and separating, drying filter residues by a dryer to obtain the battery-grade lithium carbonate, and recovering filtrate;

13) preparing rubidium-cesium salt, namely performing back extraction on the rubidium-cesium-alum prepared in the step 6) and a rubidium-cesium-potassium mixture of potassium-sodium alum by using corresponding acid, and preparing a high-purity cesium salt product and a corresponding raffinate; and performing acid stripping by using the raffinate as a raw material to prepare a high-purity rubidium salt product. The rubidium and cesium salts prepared by the step use corresponding raffinate and acid back extraction by using the existing technical scheme and acid solution.