Method for extracting lithium from clay type lithium resource
By combining sodium sulfate roasting with water leaching and multi-stage extraction technology, the problem of lithium extraction from clay-type lithium ore has been solved, achieving efficient and low-cost lithium separation and purification to obtain high-purity lithium chloride solution or lithium carbonate products.
Patent Information
- Application Number
- CN202511057910.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-10-17
AI Technical Summary
Lithium extraction from clay-type lithium resources is difficult. Existing processes result in high aluminum leaching rates, difficulty in separating lithium from additives, and low lithium concentrations, leading to high lithium extraction costs.
A high-purity lithium chloride solution was obtained by using a method combining sodium sulfate roasting with water leaching, extraction, and back-extraction, and by multi-stage extraction with P204 and β-diketone extractants.
It achieves efficient lithium extraction, reduces aluminum loss, simplifies subsequent separation processes, increases lithium concentration, avoids energy-intensive concentration steps, and provides high product selectivity.
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Figure CN120796740A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of lithium extraction, in particular to a method for extracting lithium from clay-type lithium resources. BACKGROUND
[0002] Global lithium mineral resources are mainly concentrated in geological environments such as basin brine, pegmatite, and lithium clay, among which, continental salt lake type lithium mineral accounts for 58%, pegmatite type lithium mineral accounts for 26%, and clay type lithium mineral accounts for 7%. The processing technology of salt lake type lithium mineral and pegmatite type lithium mineral is relatively mature, while clay type lithium mineral is discovered relatively late, and is still in the early stage of exploration and development due to its low lithium content.
[0003] Clay type lithium mineral resources are mainly divided into lithium chlorite, montmorillonite adsorption type, and isomorphism type due to different occurrence states of lithium, and the main minerals include volcanic clay lithium mineral, lithium-rich bauxite, and carbonate type clay lithium mineral. Clay minerals in North America are mainly montmorillonite and illite adsorption type, which are unstable in structure, and lithium can be extracted by conventional acid leaching. Lithium in southwest China is mainly kaolinite and chlorite, which are relatively stable in structure, and lithium cannot be extracted by conventional acid leaching. Lithium can be extracted only after roasting and dissociation. The existing main processes include roasting-acid leaching and additive roasting-water leaching. In the roasting-acid leaching process, the aluminum leaching rate is high, which leads to difficulties in subsequent aluminum-lithium separation. In the additive roasting-water leaching process, the selectivity of lithium is good, but there is a problem of separation of lithium and additive after separation, and the concentration of lithium after separation is low, which leads to high energy consumption of evaporation and concentration of low-concentration lithium solution, thereby greatly increasing the cost of lithium extraction.
[0004] Therefore, it is urgent to provide a method for efficiently extracting lithium from clay type lithium resources to solve the above problems. SUMMARY
[0005] The purpose of the present application is to provide a method for extracting lithium from clay type lithium resources to solve the above problems.
[0006] To achieve the above purpose, the present application provides a method for extracting lithium from clay type lithium resources, comprising: mixing and roasting clay type lithium resources and sodium sulfate to obtain a roasted material; water leaching and solid-liquid separation of the roasted material to obtain a leaching solution; mixing and reacting the leaching solution and an alkaline pH regulator to obtain a liquid after iron removal by solid-liquid separation; first extraction of the liquid after iron removal by a first extractant to obtain a first raffinate; mixing the first raffinate and sodium hydroxide to obtain a liquid after conditioning by solid-liquid separation; using a second extractant to perform a second extraction on the conditioning liquid to obtain a lithium-containing organic phase, and using hydrochloric acid to perform a back extraction on the second organic phase to obtain a lithium chloride solution; the first extractant comprises P204; the second extractant comprises a β-diketone extractant.
[0007] Optionally, the method for extracting lithium from a clay-type lithium resource satisfies at least one of the following conditions: A. the alkaline pH regulator comprises sodium hydroxide, sodium carbonate, calcium oxide, calcium hydroxide, or calcium carbonate; B. the β-diketone extractant comprises one or more of 1-phenyl-1,3-octanedione, 1-phenyl-1,3-tetradecanedione, and 1-phenyl-1,3-eicosanedione.
[0008] Optionally, the method for extracting lithium from a clay-type lithium resource satisfies at least one of the following conditions: A. the mass of the sodium sulfate is 10%-100% of the mass of the clay-type lithium resource; B. the temperature of the roasting is 400°C-950°C, and the roasting time is 0.5h-5h.
[0009] Optionally, the method for extracting lithium from a clay-type lithium resource satisfies at least one of the following conditions: A. the temperature of the water immersion is 15°C-95°C, and the time is 0.5h-5h; B. the solid-liquid ratio of the water immersion is 1g: (1mL-5mL); C. the mass concentration of sodium ions in the leaching solution is 50g / L-90g / L, the mass concentration of lithium ions is 0.1g / L-0.8g / L, and the mass ratio of sodium ions to lithium ions is 62.5-900:1.
[0010] Optionally, the method for extracting lithium from a clay-type lithium resource satisfies at least one of the following conditions: A. the pH value of the solution of the reaction is 2.5-3; B. the reaction is performed in an oxidizing system; the oxidizing agent in the oxidizing system comprises one or more of air, oxygen, or hydrogen peroxide; C. the temperature of the reaction is 50°C-95°C, and the time is 0.5h-8h.
[0011] Optionally, the method for extracting lithium from a clay-type lithium resource satisfies at least one of the following conditions: A. the first extraction comprises multi-stage countercurrent extraction; B. The first extractant further adds a first diluent, and the first diluent comprises sulfonated kerosene; C. The volume of the P204 accounts for 20%-30% of the total volume of the first diluent.
[0012] Optionally, the pH value of the conditioning liquid is 13-14.
[0013] Optionally, the method for extracting lithium from clay-type lithium resources meets at least one of the following conditions: A. The second extraction comprises multi-stage countercurrent extraction; B. The second extractant further adds a synergistic extractant, and the synergistic extractant comprises a neutral alkyl phosphine oxide extractant; C. The second extractant further adds a second diluent, and the second diluent comprises sulfonated kerosene; D. The time of the second extraction is 10-15 min.
[0014] Optionally, the method for extracting lithium from clay-type lithium resources meets at least one of the following conditions: A. The volume of the synergistic extractant accounts for 5%-50% of the total volume of the second extractant; B. The volume of the beta-diketone extractant accounts for 5%-50% of the total volume of the second extractant.
[0015] Optionally, the method for extracting lithium from clay-type lithium resources meets at least one of the following conditions: A. The first extraction also obtains an aluminum-calcium-magnesium-containing extraction organic phase, and the aluminum-calcium-magnesium-containing extraction organic phase is back-extracted by sulfuric acid to obtain an aluminum-calcium-magnesium-sulfuric acid residue; B. The second extraction also obtains a second raffinate, and the second raffinate is treated by MVR to obtain anhydrous sodium sulfate; C. The lithium chloride solution and the carbonate are mixed and solid-liquid separated to obtain lithium carbonate.
[0016] Compared with the prior art, the beneficial effects of the present application include: The method for extracting lithium from clay-type lithium resources provided in the application destroys the structure of aluminosilicate under high temperature conditions by using sodium sulfate as an additive, releases lithium in the aluminosilicate lattice and interlayer, and then realizes selective and efficient extraction of free lithium in clay-type lithium through subsequent water immersion. The leaching rate of aluminum and iron is low during the leaching process, and the concentration of aluminum and iron in the solution is less than 0.5 g / L. After the leaching solution is regulated by an alkaline pH regulator, the iron in the leaching solution is removed. After the iron-removed solution is extracted by P204, aluminum, calcium, magnesium and other divalent impurity ions are removed, and a first raffinate (high-sodium and low-lithium sulfate solution) is obtained. The pH value of the first raffinate is adjusted by sodium hydroxide, and the residual impurities in the first extraction are precipitated. After solid-liquid separation, a conditioned solution is obtained. The conditioned solution is extracted by a beta-diketone extraction system to obtain a second extraction organic phase loaded with lithium and a second raffinate. The second extraction organic phase is stripped by hydrochloric acid to obtain a lithium chloride solution, and the second raffinate is mainly a sodium sulfate solution. The two-stage extraction process is used to separate lithium, impurities and sodium in the application. The concentration of lithium chloride after stripping is high, and there is no need for concentration, which avoids the low-concentration lithium concentration process in other processes. The P204 extraction process is used to separate lithium and aluminum, which reduces the loss of lithium in the aluminum removal process. The beta-diketone extractant is used to extract lithium, and hydrochloric acid is used for stripping, so that high-purity lithium chloride solution can be directly obtained. The high-purity lithium chloride solution can be further precipitated to obtain lithium carbonate products, and the product selection is more diverse. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope of the application.
[0018] Figure 1 A method for extracting lithium from clay-type lithium resources is provided for Example 1. DETAILED DESCRIPTION
[0019] As used herein, the term: "prepared from" is synonymous with "comprising". The terms "comprising", "including", "having" "with" or any other variation thereof, as used in the present document, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device that includes the listed elements does not necessarily limit to those elements only, but can include other elements not explicitly listed or inherent to such composition, step, method, article or device.
[0020] The conjunctive term "consisting of' excludes any element, step, or component not specified. If used in a claim, this phrase shall not be construed to mean that the recited material is essential to the claim, but rather that the claim uses the phrase "consisting of' to purport to further limit the claim to the specific elements, steps, or components that are recited. The phrase "consisting of' shall not be interpreted to mean that the recited elements, steps, or components are the only ones that can be present in the claim.
[0021] When expressing a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values for an equivalent, concentration, or other value or parameter, it shall be understood that all ranges formed by any pairing of an upper range limit or preferred value with a lower range limit or preferred value, whether or not the range is expressly disclosed, are specifically disclosed. For example, where a range "1-5" is disclosed, the described range should be interpreted to include the ranges "1-4," "1-3," "1-2," "1-2 and 4-5," "1-3 and 5," etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include the endpoints and all integers and fractions within that range.
[0022] In these examples, the parts and percentages are by mass unless otherwise indicated.
[0023] "Mass parts" refers to a basic unit of measurement that represents the proportional relationship of the mass of multiple components, 1 part can represent any unit mass, such as 1 g, 2.689 g, etc. If we say that the mass parts of component A is a parts, and the mass parts of component B is b parts, it means that the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK, and the mass of component B is bK (K is an arbitrary number, representing a multiple factor). It should not be misunderstood that unlike mass parts, the sum of the mass parts of all components is not limited to 100 parts.
[0024] "and / or" is used to indicate that one or both of the described conditions can occur, for example, A and / or B includes (A and B) and (A or B).
[0025] The present application provides a method for extracting lithium from clay-type lithium resources, comprising: mixing the clay-type lithium resources and sodium sulfate, and roasting to obtain a roasted material; water leaching the roasted material, and solid-liquid separation to obtain a leaching solution; It should be noted that the present application uses sodium sulfate as an auxiliary agent for roasting and water immersion to obtain a high-sodium and low-lithium leaching solution. Since lithium and sodium belong to the same main group elements and have similar properties, it is difficult to separate them by simply adjusting the pH value. Carbonation and phosphatization precipitation can separate lithium and sodium, but due to the low content of lithium in the solution, both precipitation methods are difficult to precipitate completely. The freeze crystallization method can achieve partial removal of sodium, but the lithium content in the solution after crystallization is still low, and multiple concentration is still required to achieve lithium enrichment; The leaching solution and an acidic pH adjuster are mixed and reacted to obtain a post-iron removal solution after solid-liquid separation; It should be noted that the efficient removal of iron can be achieved by simply adjusting the pH value, and the use of sodium or calcium base does not introduce other impurity ions, which can ensure the purity of the circulating sodium salt in the system; The post-iron removal solution is subjected to first extraction using a first extractant to obtain a first raffinate; It should be noted that due to the traditional pH adjustment process for removing aluminum, a large amount of lithium is lost due to the adsorption of a large amount of lithium by the aluminum hydroxide precipitate. However, by using the extraction process, aluminum and other calcium and magnesium impurities can be extracted and removed. P204 does not extract lithium, leaving lithium and sodium in the raffinate, which achieves a one-time efficient separation of lithium, sodium, aluminum, calcium, and magnesium impurities. The first raffinate is mixed with sodium hydroxide, and solid-liquid separation is performed to obtain a post-conditioning solution; It should be noted that the lithium extraction system of the diketone requires an alkaline system. Therefore, the first raffinate is adjusted to alkaline by sodium hydroxide to meet the pH requirements of the second extraction system. At the same time, magnesium that has not been removed in the first extraction process can be precipitated, thereby achieving deep purification of the solution; The post-conditioning solution is subjected to second extraction using a second extractant to obtain a lithium-containing organic phase. The second extraction organic phase is subjected to back extraction using hydrochloric acid to obtain a lithium chloride solution; It should be noted that the diketone extraction system can achieve selective extraction of lithium in an alkaline system. Other ions, such as sodium ions, are not extracted, thereby achieving selective extraction of lithium. The organic phase loaded with lithium can be back-extracted and enriched in the back-extraction solution by hydrochloric acid. The lithium concentration in the back-extraction solution is high, and there are no other impurity ions. Therefore, pure lithium chloride products can be obtained by direct concentration and crystallization, or pure lithium carbonate products can be obtained by carbonation precipitation without secondary purification treatment; The first extractant includes P204; The second extractant includes a beta-diketone extractant.
[0026] Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. The acidic pH adjuster includes sulfuric acid; It is noted that when the acidic pH adjuster comprises sulfuric acid, no other impurities are introduced; B. the beta-diketone extractant comprises one or more of 1-phenyl-1,3-octanedione, 1-phenyl-1,3-tetradecanedione, and 1-phenyl-1,3-eicosanedione.
[0027] Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. the mass of the sodium sulfate is 10%-100% of the mass of the clay-type lithium resources; Optionally, the mass of the sodium sulfate can be 10%, 20%, 40%, 60%, 80%, 100%, or any value between 10%-100% of the mass of the clay-type lithium resources; B. the temperature of the roasting is 400℃-950℃, and the roasting time is 0.5h-5h.
[0028] Optionally, the temperature of the roasting can be 400℃, 500℃, 600℃, 700℃, 800℃, 900℃, 950℃, or any value between 400℃-950℃, and the roasting time can be 0.5h, 1h, 2h, 4h, 5h, or any value between 0.5h-5h.
[0029] Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. the temperature of the water immersion is 15℃-95℃, and the time is 0.5h-5h; Optionally, the temperature of the water immersion can be 15℃, 20℃, 50℃, 90℃, 95℃, or any value between 15℃-95℃, and the time can be 0.5h, 1h, 2h, 4h, 5h, or any value between 0.5h-5h; B. the solid-liquid ratio of the water immersion is 1g: (1mL-5mL); Optionally, the solid-liquid ratio of the water immersion can be 1g:1mL, 1g:2mL, 1g:3mL, 1g:4mL, 1g:5mL, or any value between 1g: (1mL-5mL); C. the mass concentration of sodium ions in the leaching solution is 50g / L-90g / L, the mass concentration of lithium ions is 0.1g / L-0.8g / L, and the mass ratio of sodium ions to lithium ions is 62.5-900:1.
[0030] Optionally, the mass concentration of sodium ions in the leaching solution can be 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, or any value between 50 g / L and 90 g / L, the mass concentration of lithium ions can be 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, or any value between 0.1 g / L and 0.8 g / L, and the mass ratio of sodium ions to lithium ions can be 62.5:1, 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 900:1, or any value between 62.5:1 and 900:1. Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. The pH value of the solution of the reaction is 2.5-3; Optionally, the pH value of the solution of the reaction can be 2.5, 2.6, 2.7, 2.8, 2.9, 3, or any value between 2.5 and 3; B. The reaction is carried out in an oxidative system; the oxidizing agent in the oxidative system includes one or more of air, oxygen, and hydrogen peroxide; It should be noted that the oxidative system can deeply oxidize a small amount of ferrous ions present in the solution, and the oxidized ferric ions are easily precipitated under low pH conditions, thereby achieving complete precipitation of the iron ions in the solution; C. The temperature of the reaction is 50℃-95℃, and the time is 0.5h-8h.
[0031] Optionally, the temperature of the reaction can be 50℃, 60℃, 70℃, 80℃, 90℃, 95℃, or any value between 50℃ and 95℃, and the time can be 0.5h, 1h, 2h, 4h, 6h, 8h, or any value between 0.5h and 8h.
[0032] Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. The first extraction includes multi-stage countercurrent extraction; B. The first extractant further adds a first diluent, and the first diluent includes sulfonated kerosene; C. The volume of P204 accounts for 20%-30% of the total volume of the first diluent.
[0033] Optionally, the volume of P204 can account for 20%, 25%, 30%, or any value between 20% and 30% of the total volume of the first diluent.
[0034] Optionally, the pH value of the conditioned solution is 13-14.
[0035] Optionally, the pH value of the conditioned solution can be 13, 13.5, 14, or any value between 13 and 14.
[0036] It should be noted that controlling the pH value of the conditioned solution between 13 and 14 can ensure the complete precipitation of impurity ions such as magnesium and also provide the required pH value range for the diketone extraction system, ensuring efficient extraction of lithium and improving the extraction rate of lithium. Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. The second extraction includes multi-stage countercurrent extraction. B. The second extractant further adds a synergistic extractant, and the synergistic extractant includes a neutral alkyl phosphorus-based extractant. C. The second extractant further adds a second diluent, and the second diluent includes sulfonated kerosene. D. The time of the second extraction is 10-15 min.
[0037] Optionally, the time of the second extraction can be 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, or any value between 10 min and 15 min.
[0038] It should be noted that when performing the second extraction, the number of extractions and the number of washing stages can be increased.
[0039] It should also be noted that multi-stage countercurrent stripping with hydrochloric acid can directly obtain a high-purity lithium chloride solution, and the high-purity lithium chloride solution can be further precipitated to obtain a lithium carbonate product. For example, the lithium chloride solution is precipitated with sodium carbonate to obtain a lithium carbonate product.
[0040] Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. The volume of the synergistic extractant accounts for 5%-50% of the total volume of the second extractant. Optionally, the volume of the synergistic extractant can account for 5%, 10%, 25%, 50%, or any value between 5% and 50% of the total volume of the second extractant. B. The volume of the β-diketone-based extractant accounts for 5%-50% of the total volume of the second extractant.
[0041] Optionally, the volume of the β-diketone-based extractant can account for 5%, 10%, 25%, 50%, or any value between 5% and 50% of the total volume of the second extractant.
[0042] Optionally, the method for extracting lithium from clay-type lithium resources satisfies at least one of the following conditions: A. The first extraction also obtains an aluminum, calcium and magnesium-containing extraction organic phase, and the aluminum, calcium and magnesium-containing extraction organic phase is back-extracted with sulfuric acid to obtain an aluminum, calcium and magnesium sulfuric acid residue; B. The second extraction also obtains a second raffinate, and the second raffinate is subjected to MVR treatment to obtain anhydrous sodium sulfate; It should be noted that the anhydrous sodium sulfate is returned to the roasting process, thereby realizing the circulation of the auxiliary agent sodium sulfate; C. The lithium chloride solution and the carbonate are mixed and subjected to solid-liquid separation to obtain lithium carbonate.
[0043] The embodiments of the present application will be described in detail below with reference to specific examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.
[0044] Example 1 The present example provides a method for efficiently extracting lithium from clay-type lithium resources, and the specific steps include: S1: Take 2000g of clay-type lithium resource powder, add 1000g of anhydrous sodium sulfate, mix and then roast, the roasting temperature is 800℃, the roasting time is 2h, and the roasted material is obtained; S2: The roasted material is subjected to water immersion to obtain a slurry, the solid-liquid ratio of the immersion is 1g:2mL, the temperature of the immersion is 90℃, the time of the immersion is 1h, and solid-liquid separation is performed to obtain a water immersion liquid and an immersion residue; S3: The water immersion liquid is adjusted to a pH value of 2.5 by 30% NaOH, and air is used as an oxidizing agent to perform an iron removal reaction, the iron removal reaction temperature is 90℃, the iron removal reaction time is 6h, and solid-liquid separation is performed to obtain an iron-removed liquid and an iron residue; S4: The iron-removed liquid is subjected to three-stage countercurrent extraction with an extractant (P204 and sulfonated kerosene are mixed to prepare, P204 accounts for 20% of the total volume of the extractant), the extraction temperature is 40℃, the extraction phase ratio is 1:5, the mixing time is 10min, the obtained first raffinate enters the next process, and the loaded organic phase is back-extracted with 50g / L H2SO4 and then evaporated and crystallized to obtain a calcium, aluminum and magnesium residue; S5: The P204 raffinate is adjusted to a pH value of 13 by 30% NaOH, and solid-liquid separation is performed to obtain a conditioned liquid and a small amount of magnesium residue; S6: The conditioned liquid is subjected to three-stage countercurrent extraction with an extractant (a mixture of a beta-diketone extractant, a neutral alkyl phosphine oxide extractant and sulfonated kerosene, wherein the volume ratio of the beta-diketone extractant, the neutral alkyl phosphine oxide extractant and the sulfonated kerosene is 40%:10%:50%), the extraction temperature is 40 DEG C, the extraction phase ratio is 1:1, and the mixing time is 10 min, to obtain a second raffinate and a negative lithium organic phase, the second raffinate is concentrated by MVR to obtain sodium sulfate which is returned to the roasting process, and the negative lithium organic phase is subjected to back extraction with 3 mol / L HCl, the back extraction temperature is 40 DEG C, the back extraction phase ratio is 10:1, and the mixing time is 15 min, to obtain a high-concentration lithium chloride solution which is then precipitated with saturated sodium carbonate to obtain lithium carbonate product.
[0045] The method for extracting lithium from clay-type lithium resources provided in this embodiment has the process as shown in Figure 1 The recovery results are shown in Table 1.
[0046] Table 1: Recovery results
[0047] Example 2 The method for efficiently extracting lithium from clay-type lithium resources provided in this embodiment has the following specific steps: S1: 2000g of clay-type lithium resource powder is taken, 1000g of anhydrous sodium sulfate is added, and after mixing, roasting is performed, the roasting temperature is 800 DEG C, and the roasting time is 2h, to obtain roasted material; S2: The roasted material is subjected to water immersion to obtain a slurry, the immersion solid-liquid ratio is 1g:2mL, the immersion temperature is 90 DEG C, and the immersion time is 1h, and after solid-liquid separation, a water immersion liquid and an immersion residue are obtained; S3: The water immersion liquid is adjusted to a pH value of 2.7 by 30% NaOH, and an iron removal reaction is performed with oxygen as an oxidizing agent, the iron removal reaction temperature is 90 DEG C, the iron removal reaction time is 6h, and after solid-liquid separation, an iron-removed liquid and an iron residue are obtained; S4: The iron-removed liquid is subjected to three-stage countercurrent extraction with an extractant (prepared by mixing P204 and sulfonated kerosene, and P204 accounts for 20% of the total volume of the extractant), the extraction temperature is 40 DEG C, the extraction phase ratio is 1:5, and the mixing time is 10 min, to obtain a first raffinate which enters the next process, and a loaded organic phase which is subjected to back extraction with 50g / L H2SO4 and then evaporated and crystallized to obtain calcium-aluminum-magnesium residue; S5: The P204 raffinate is adjusted to a pH value of 13.5 by 30% NaOH, and after solid-liquid separation, a conditioned liquid and a small amount of magnesium residue are obtained; S6: The conditioned liquid is subjected to three-stage countercurrent extraction with an extractant (a β-diketone extractant, a neutral alkyl phosphine oxide extractant, and a diluent mixed to obtain a volume ratio of 40%:10%:50%), an extraction temperature of 40 DEG C, an extraction phase ratio of 1:1, and a mixing time of 10 min to obtain a second raffinate and a lithium-deficient organic phase. The second raffinate is concentrated by MVR to obtain sodium sulfate which is returned to the roasting process. The lithium-deficient organic phase is subjected to back extraction with 3 mol / L HCl at an extraction temperature of 40 DEG C, an extraction phase ratio of 15:1, and a mixing time of 15 min to obtain a high-concentration lithium chloride solution which is then precipitated with saturated sodium carbonate to obtain lithium carbonate products.
[0048] The recovery results are shown in Table 2.
[0049] Table 2 Recovery results
[0050] Example 3 The embodiment provides a method for efficiently extracting lithium from clay-type lithium resources, and the specific steps include: S1: 2000g of clay-type lithium resource powder is taken, 1000g of anhydrous sodium sulfate is added, and after mixing, roasting is performed at a roasting temperature of 850 DEG C for 2h to obtain a roasted material; S2: The roasted material is subjected to water immersion to obtain a slurry, the immersion solid-liquid ratio is 1g:2mL, the immersion temperature is 90 DEG C, and the immersion time is 1h, and after solid-liquid separation, a water immersion liquid and an immersion residue are obtained; S3: The water immersion liquid is adjusted to a pH value of 2.9 by 30% NaOH, and an iron removal reaction is performed with oxygen as an oxidant, the iron removal reaction temperature is 90 DEG C, the iron removal reaction time is 5h, and after solid-liquid separation, an iron-removed liquid and an iron residue are obtained; S4: The iron-removed liquid is subjected to three-stage countercurrent extraction with an extractant (P204 and sulfonated kerosene mixed to obtain, P204 accounts for 20% of the total volume of the extractant), an extraction temperature of 40 DEG C, an extraction phase ratio of 1:5, and a mixing time of 10 min to obtain a first raffinate which enters the next process, and a loaded organic phase which is back extracted with 50g / L H2SO4 and then evaporated and crystallized to obtain a calcium-aluminum-magnesium residue; S5: The P204 raffinate is adjusted to a pH value of 13.6 by 30% NaOH, and after solid-liquid separation, a conditioned liquid and a small amount of magnesium residue are obtained; S6: The conditioned liquid is subjected to three-stage countercurrent extraction with an extractant (a β-diketone extractant, a neutral alkyl phosphine oxide extractant, and a diluent mixed to obtain a volume ratio of 40%:10%:50%), an extraction temperature of 40°C, an extraction phase ratio of 1:1, and a mixing time of 10 min to obtain a second raffinate and a negative lithium organic phase. The second raffinate is concentrated by MVR to obtain sodium sulfate which is returned to the roasting process, and the negative lithium organic phase is subjected to back extraction with 3 mol / L HCl at an extraction temperature of 40°C, an extraction phase ratio of 8:1, and a mixing time of 15 min to obtain a high-concentration lithium chloride solution which is then precipitated with saturated sodium carbonate to obtain lithium carbonate products.
[0051] The recovery results are shown in Table 3.
[0052] Table 3 Recovery results
[0053] Example 4 The embodiment provides a method for efficiently extracting lithium from clay-type lithium resources, and the specific steps include: S1: 2000g of clay-type lithium resource powder is taken, 1000g of anhydrous sodium sulfate is added, and after mixing, roasting is performed at a roasting temperature of 800°C for 2h to obtain a roasted material; S2: The roasted material is subjected to water immersion to obtain a slurry, the immersion solid-liquid ratio is 1g:2mL, the immersion temperature is 90°C, and the immersion time is 1h, and after solid-liquid separation, a water immersion liquid and an immersion residue are obtained; S3: The water immersion liquid is adjusted to a pH value of 3 by 30% NaOH, and an iron removal reaction is performed with oxygen as an oxidizing agent, the iron removal reaction temperature is 90°C, the iron removal reaction time is 6h, and after solid-liquid separation, an iron-removed liquid and an iron residue are obtained; S4: The iron-removed liquid is subjected to three-stage countercurrent extraction with an extractant (P204 and sulfonated kerosene mixed to obtain, P204 accounts for 20% of the total volume of the extractant), an extraction temperature of 40°C, an extraction phase ratio of 1:5, and a mixing time of 10 min to obtain a first raffinate which enters the next process, and a loaded organic phase which is back extracted with 50g / L H2SO4 and then evaporated and crystallized to obtain a calcium-aluminum-magnesium residue; S5: The P204 raffinate is adjusted to a pH value of 13.5 by 30% NaOH, and after solid-liquid separation, a conditioned liquid and a small amount of magnesium residue are obtained; S6: The conditioned liquid is subjected to three-stage countercurrent extraction with an extractant (a β-diketone extractant, a neutral alkyl phosphine oxide extractant, and a diluent mixed to obtain a volume ratio of 40%:10%:50%), an extraction temperature of 40°C, an extraction phase ratio of 1:1, and a mixing time of 10 min to obtain a second raffinate and a lithium-deficient organic phase. The second raffinate is concentrated by MVR to obtain sodium sulfate which is returned to the roasting process. The lithium-deficient organic phase is subjected to back extraction with 3 mol / L HCl at an extraction temperature of 40°C, an extraction phase ratio of 12:1, and a mixing time of 15 min to obtain a high-concentration lithium chloride solution which is then precipitated with saturated sodium carbonate to obtain lithium carbonate products.
[0054] The recovery results are shown in Table 4.
[0055] Table 4 Recovery results
[0056] Example 5 The embodiment provides a method for efficiently extracting lithium from clay-type lithium resources, and the specific steps include: S1: 2000g of clay-type lithium resource powder is taken, 1000g of anhydrous sodium sulfate is added, and after mixing, roasting is performed at a roasting temperature of 800°C for 2h to obtain a roasted material; S2: The roasted material is subjected to water immersion to obtain a slurry, the immersion solid-liquid ratio is 1g:2mL, the immersion temperature is 90°C, and the immersion time is 1h, and after solid-liquid separation, a water immersion liquid and an immersion residue are obtained; S3: The water immersion liquid is adjusted to a pH value of 2.5 by 30% NaOH, and a hydrogen peroxide solution is used as an oxidizing agent to perform an iron removal reaction, the iron removal reaction temperature is 90°C, the iron removal reaction time is 6h, and after solid-liquid separation, an iron-removed liquid and an iron residue are obtained; S4: The iron-removed liquid is subjected to three-stage countercurrent extraction with an extractant (P204 and sulfonated kerosene mixed to obtain, P204 accounts for 20% of the total volume of the extractant), an extraction temperature of 40°C, an extraction phase ratio of 1:5, and a mixing time of 10 min to obtain a first raffinate which enters the next process, and a loaded organic phase which is back extracted with 50g / L H2SO4 and then evaporated and crystallized to obtain a calcium-aluminum-magnesium residue; S5: The P204 raffinate is adjusted to a pH value of 13.3 by 30% NaOH, and after solid-liquid separation, a conditioned liquid and a small amount of magnesium residue are obtained; S6: The conditioned liquid is subjected to three-stage countercurrent extraction with an extractant (a mixture of a β-diketone extractant, a neutral alkyl phosphine oxide extractant and a diluent, wherein the volume ratio of the β-diketone extractant, the neutral alkyl phosphine oxide extractant and the diluent is 40%:10%:50%), the extraction temperature is 40°C, the extraction phase ratio is 1:1, and the mixing time is 10 min, to obtain a second raffinate and a negative lithium organic phase, the second raffinate is concentrated by MVR to obtain sodium sulfate which is returned to the roasting process, and the negative lithium organic phase is subjected to back extraction with 3 mol / L HCl, the back extraction temperature is 40°C, the back extraction phase ratio is 20:1, and the mixing time is 15 min, to obtain a high-concentration lithium chloride solution, which is then precipitated with saturated sodium carbonate to obtain lithium carbonate product.
[0057] The recovery results are shown in Table 5.
[0058] Table 5 Recovery results
[0059] Comparative Example 1 The difference from Example 1 is that in the S3 iron removal step of this comparative example, the pH value is controlled at 3.50, and the other conditions are consistent with Example 1. The recovery results are shown in Table 7.
[0060] Table 7 Recovery results
[0061] Comparative Example 2 The difference from Example 1 is that this comparative example does not remove iron, but directly uses P204 extraction to remove impurities, and the other conditions are consistent with Example 1. The recovery results are shown in Table 8.
[0062] Table 8 Recovery results
[0063] Comparative Example 3 The difference from Example 1 is that the pH of the conditioned liquid in this comparative example is 12, and the other conditions are consistent with Example 1. The recovery results are shown in Table 9.
[0064] Table 9 Recovery results
[0065] Comparative Example 4 The difference from Example 1 is that the pH of the conditioned liquid in this comparative example is 10.5, and the other conditions are consistent with Example 1. The recovery results are shown in Table 10.
[0066] Table 10 Recovery results
[0067] Comparative Example 5 The difference from Example 1 is that the S5 step is not performed in this comparative example, and other conditions are consistent with Example 1. The recovery results are shown in Table 11.
[0068] Table 11 Recovery results
[0069] Comparative Example 6 The difference from Example 1 is that the first extractant P204 is replaced by P507 in this comparative example, and other conditions are consistent with Example 1. The recovery results are shown in Table 12.
[0070] Table 12 Recovery results
[0071] Comparative Example 7 The difference from Example 1 is that the second extractant β-diketone extractant is replaced by P204 in this comparative example, and other conditions are consistent with Example 1. The recovery results are shown in Table 13.
[0072] Table 13 Recovery results
[0073] Analysis: From the above tests, Examples 1-5 prove that the lithium ion concentration in the lithium stripping solution prepared according to the method provided in the present application can reach more than 5 g / L, the lithium and sodium are well separated, and high-purity lithium chloride solution can be obtained after multi-stage extraction, washing and stripping.
[0074] Comparative Example 1 proves that when the pH value for removing iron is high, the precipitation rate of aluminum is high, and at the same time, the loss rate of lithium is high, resulting in a low lithium concentration in the subsequent lithium stripping solution.
[0075] Comparative Examples 3-4 prove that when the pH value of the conditioned solution is low, the extraction rate of lithium is low, resulting in a low lithium concentration and an increased sodium concentration in the subsequent lithium stripping solution.
[0076] Comparative Example 5 proves that without conditioning treatment, the P204 raffinate is directly extracted, the extraction of lithium and aluminum is low, the lithium content in the second raffinate is high, and it is difficult to obtain a high-concentration lithium chloride solution.
[0077] Comparative Example 6 proves that by replacing P204 with P507, the aluminum concentration in the first raffinate is high, and after conditioning treatment, the aluminum concentration is still difficult to remove, affecting the composition of the subsequent lithium chloride solution.
[0078] Comparative Example 7 proves that by replacing the diketone extractant with P204, the extraction rate of lithium is low during the second extraction process, making it difficult to obtain a high-concentration lithium chloride solution.
[0079] Finally, it should be noted that the above-described embodiments are merely intended for describing and illustrating, but not limiting the technical solutions of the present application; even though the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or equivalently replace some or all of the technical features thereof; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.
[0080] Furthermore, those skilled in the art will appreciate that a combination of features from different embodiments can be meant to be within the scope of the present application and form a different embodiment, although some embodiments herein include certain features rather than others included in other embodiments. For example, in the claims above, any of the claimed embodiments can be used in any combination. The information disclosed in this Background section is intended only to enhance an understanding of the general background of the present application, and should not be taken as an acknowledgement or any form of suggestion that this information forms a prior art that is already publicly known.
Claims
1. A method for extracting lithium from clay-type lithium resources, characterized in that: include: Mixing clay-type lithium resources and sodium sulfate, and calcining to obtain a calcined material; The roasted material is subjected to water immersion and solid-liquid separation to obtain a leachate; The leachate and the alkaline pH regulator are mixed and reacted, and the solid-liquid separation is performed to obtain a deironed liquid; performing a first extraction on the deironed liquid using a first extractant to obtain a first raffinate; mixing the first raffinate and sodium hydroxide, and performing solid-liquid separation to obtain a conditioned liquid; Performing a second extraction on the conditioned liquid with a second extractant to obtain a lithium-containing extracted organic phase, and back-extracting the second extracted organic phase with hydrochloric acid to obtain a lithium chloride solution; The first extractant includes P204; The second extractant includes a β-diketone extractant.
2. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: At least one of the following conditions is met: A. The alkaline pH regulator includes sodium hydroxide, sodium carbonate, calcium oxide, calcium hydroxide, and calcium carbonate; B. The β-diketone extractant includes one or more of 1-phenyl-1,3-octanedione, 1-phenyl-1,3-tetradecanedione and 1-phenyl-1,3-eicosanedione.
3. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: At least one of the following conditions is met: A. The mass of the sodium sulfate is 10%-100% of the mass of the clay-type lithium resource; B. The calcination temperature is 400° C.-950° C., and the calcination time is 0.5 h-5 h.
4. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: At least one of the following conditions is met: A. The water immersion temperature is 15°C-95°C and the time is 0.5h-5h; B. The solid-to-liquid ratio of the water immersion is 1g:(1mL-5mL); C. The mass concentration of sodium ions in the leachate is 50 g / L-90 g / L, the mass concentration of lithium ions is 0.1 g / L-0.8 g / L, and the mass ratio of sodium ions to lithium ions is 62.5-900:
1.
5. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: At least one of the following conditions is met: A. The pH value of the reaction solution is 2.5-3; B. The reaction is carried out in an oxidizing system; the oxidant in the oxidizing system includes one or more of air, oxygen, and hydrogen peroxide; C. The reaction temperature is 50°C-95°C and the reaction time is 0.5h-8h.
6. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: At least one of the following conditions is met: A. the first extraction comprises multi-stage countercurrent extraction; B. adding a first diluent to the first extractant, wherein the first diluent comprises sulfonated kerosene; C. The volume of the P204 accounts for 20%-30% of the total volume of the first diluent.
7. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: The pH value of the conditioned liquid is 13-14.
8. The method for extracting lithium from clay-type lithium resources according to claim 1, characterized in that: At least one of the following conditions is met: A. the second extraction comprises multi-stage countercurrent extraction; B. The second extractant is further added with a synergist, wherein the synergist comprises a neutral alkylphosphine extractant; C. adding a second diluent to the second extractant, wherein the second diluent comprises sulfonated kerosene; D. The second extraction time is 10-15 minutes.
9. The method for extracting lithium from clay-type lithium resources according to claim 8, characterized in that: At least one of the following conditions is met: A. the volume of the co-extraction agent accounts for 5%-50% of the total volume of the second extraction agent; B. The volume of the β-diketone extractant accounts for 5%-50% of the total volume of the second extractant.
10. The method for extracting lithium from clay-type lithium resources according to any one of claims 1 to 9, characterized in that: At least one of the following conditions is met: A. The first extraction also obtains an aluminum, calcium, and magnesium-containing extracted organic phase, and the aluminum, calcium, and magnesium-containing extracted organic phase is back-extracted with sulfuric acid to obtain aluminum, calcium, and magnesium sulfate residue; B. The second extraction further produces a second raffinate, and the second raffinate is subjected to MVR treatment to produce anhydrous sodium sulfate; C. The lithium chloride solution and carbonate are mixed and solid-liquid separated to obtain lithium carbonate.