Method for preparing lithium-containing solution through low-temperature roasting of spodumene concentrate

Abstract

The invention provides a method for preparing a lithium-containing solution through low-temperature roasting of spodumene concentrate, and relates to the field of metallurgy. The method comprises the following steps: crushing spodumene concentrate to obtain spodumene mineral powder, and mixing the spodumene mineral powder with a chlorination auxiliary agent to obtain a mixture; roasting the mixed material pellets before roasting to obtain roasted sand; and the roasted sand is subjected to water leaching, extraction, washing and reverse extraction, and a lithium-containing solution is obtained. According to the scheme, the related technological process is simple, the spodumene mineral powder and the chlorination auxiliary agent are mixed, then coke and a small amount of water are added to prepare the pellets, the temperature for converting the spodumene from the alpha crystal form to the beta crystal form is lower, the roasting effect is more uniform, and through the roasting process, the lithium element in the spodumene can be more effectively converted into the lithium-containing solution easy to extract.

Description

Technical Field

[0001] The present application relates to the field of metallurgy, and in particular to a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate. Background Art

[0002] Traditional spodumene roasting and leaching of lithium requires the roasting temperature to be raised to about 1200℃, and the spodumene transforms from the α crystal form to the β crystal form. In order to extract lithium from natural ore, natural spodumene can only be transformed by crystal form conversion roasting, so that it is transformed from monoclinic α-spodumene to tetragonal β-spodumene. The physical and chemical properties of the mineral also change significantly with the changes in the crystal structure, presenting a tetragonal crystal framework structure, with increased chemical activity, and can undergo various reactions with acids and alkalis.

[0003] Granulation is a key pretreatment technology that significantly improves the efficiency of subsequent roasting and leaching processes by processing powder into particles or pellets with a certain strength and particle size distribution. The granulation process can reduce the dust phenomenon of powder during roasting, reduce lithium loss, and improve the metal recovery rate by improving the permeability and reaction uniformity of the material, optimizing the reaction conditions. The pellets after granulation show better stability during high-temperature treatment, reduce the proportion of fine powder, and improve production efficiency. The granulation process reduces environmental pollution by reducing the generation of dust, improves the operating environment, and ensures the safety and sustainability of the production process.

[0004] Anhydrous lithium chloride is a basic chemical raw material in the lithium industry. In recent years, the lithium chloride industry has ushered in unprecedented development opportunities and entered a new stage of rapid development, given the significant growth in demand for lithium metal and its derivatives in high-tech application fields such as controlled nuclear fusion, aluminum-lithium alloy materials, lithium-ion battery technology, and optical communication nonlinear optical materials. At present, the industrial production and preparation of anhydrous lithium chloride mainly relies on the conversion method of lithium carbonate or lithium hydroxide. In the purification and refining of lithium chloride, researchers have focused on the impurity elements that have a significant impact on the electrolysis of metal lithium, such as sodium, iron, magnesium, calcium, sulfate ions, and water. According to the differences in the sources of lithium chloride, lithium extraction processes can be divided into two categories: one type of process mainly processes the primary lithium chloride solution obtained by the conversion method. The raw materials of these solutions are widely sourced, including ores, lithium carbonate, and lithium hydroxide. For this type of lithium chloride solution, researchers usually use the phase transformation law or solubility difference of elements in different solution systems to effectively remove impurity ions such as calcium, boron, and sulfate by chemical precipitation, and achieve efficient separation of sodium ions by freezing precipitation. Another type of process focuses on processing lithium chloride solutions extracted from salt lake brine. In salt lake brine, chloride ions dominate, and it also contains a large amount of impurity ions such as magnesium, calcium, sodium, and potassium. For this type of lithium-containing solution, researchers usually use the differences in the distribution coefficients of elements between different phases or the size screening effect to achieve the enrichment and purification of lithium elements and the deep removal of impurity elements through extraction, adsorption, and membrane separation technology. Summary of the invention

[0005] The purpose of this application is to provide a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate to solve the above-mentioned problems.

[0006] To achieve the above objectives, this application adopts the following technical solutions: The present application provides a method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent, the method comprising: crushing the spodumene concentrate to obtain spodumene ore powder, mixing the spodumene ore powder with a chlorination auxiliary agent to obtain a mixture; adding coke and water to prepare mixture pellets, roasting the mixture pellets to obtain roasted sand; and immersing, extracting and purifying the roasted sand to obtain a lithium-containing solution.

[0007] Optionally, the lithium content in the spodumene concentrate is 3-8%.

[0008] Optionally, the fineness of the spodumene ore powder is 200-325 mesh.

[0009] Optionally, the chlorination aid includes at least one of calcium chloride, magnesium chloride, ammonium chloride, potassium chloride, sodium chloride and calcium oxide.

[0010] Optionally, based on the mass of the mixture itself being 100%, the content of the spodumene ore powder is 50-70%.

[0011] Optionally, the ratio of the spodumene ore powder to the chlorination aid in the mixture is 1:0.8-1.5.

[0012] Optionally, the mixture is added with 3%-8% coke and mixed with water to obtain the mixture pellets, and the particle size of the mixture pellets is 5-15 mm.

[0013] Optionally, the particles are calcined at a temperature of 900-1100° C. for 2-5 hours.

[0014] Optionally, the water leaching is carried out at a liquid-to-solid ratio of 2-5 mL of water to 1 g of the spodumene ore powder, a leaching temperature of 60° C.-90° C., a leaching time of 1-3 hours, and normal pressure.

[0015] Optionally, the extraction includes subjecting the extract to three-stage extraction, three-stage washing, and two-stage countercurrent stripping to obtain a lithium-containing solution.

[0016] The present application also provides a lithium-containing solution, which is prepared by the method of preparing the lithium-containing solution by granulating and roasting the spodumene concentrate with a low-temperature auxiliary agent.

[0017] Compared with the prior art, the beneficial effects of this application include: The present application provides a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate, and this solution can be used to prepare lithium chloride products. The process flow involved in this scheme is relatively simple, mainly including steps such as crushing, mixing, roasting, water leaching, extraction and evaporation crystallization, and is easy to operate and control. Traditional spodumene roasting and leaching lithium requires the roasting temperature to be increased to about 1250°C. The present application mixes spodumene ore powder and a chlorination aid, adds coke and water to form pellets, so that the temperature at which spodumene transforms from an α-crystalline form to a β-crystalline form is lower. Through the roasting process, the lithium element in spodumene can be more effectively converted into a lithium-containing solution that is easy to extract. Subsequent extraction, washing, stripping and other steps can further obtain a lithium-containing solution. Through this scheme, the lithium element can be effectively extracted and converted into a high-value-added lithium-containing solution, thereby improving the lithium recovery rate.

[0018] The lithium-containing solution provided in the present application has high purity and can be widely used in high-tech application fields such as controlled nuclear fusion, aluminum-lithium alloy materials, lithium-ion battery technology, and optical communication nonlinear optical materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0020] Figure 1 A schematic flow chart of a method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent provided in an embodiment; Figure 2 The low temperature transformation XRD pattern of spodumene concentrate provided. DETAILED DESCRIPTION

[0021] As used herein: "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0022] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0023] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0024] In these examples, parts and percentages are by mass unless otherwise indicated.

[0025] "Mass parts" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass parts of component A are a parts and the mass parts of component B are b parts, it means 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, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts.

[0026] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0027] In order to better explain the technical solution provided by this application, an overall statement of the technical solution is first made before the embodiments.

[0028] The present application provides a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate, the method comprising: crushing the spodumene concentrate to obtain spodumene ore powder, mixing the spodumene ore powder with auxiliary agents such as chlorination to obtain a mixture; adding coke and a small amount of water to the mixture to form pellets, roasting the mixed pellets to obtain roasted sand; and immersing, extracting and purifying the roasted sand to obtain a lithium-containing solution.

[0029] In an optional embodiment, the lithium content in the spodumene concentrate is 3-8%. Spodumene is an important mineral raw material for extracting lithium, and the lithium in its concentrate mainly exists in the form of lithium oxide (Li2O). In the process of preparing a lithium-containing solution, spodumene concentrate is used as a lithium source, and the lithium content of the spodumene concentrate and the impurity content therein will directly affect the purity of the lithium chloride finally obtained. Therefore, when selecting spodumene concentrate, it is necessary to strictly control its lithium content and impurity content to ensure the quality of the final product. The lithium content of spodumene concentrate will also affect the process parameters for preparing lithium chloride, such as reaction temperature, reaction time, ratio of reactants, etc. By optimizing these process parameters, the yield and purity of the lithium-containing solution can be improved while reducing production costs.

[0030] Optionally, the lithium content in the spodumene concentrate may be 3%, 4%, 5%, 6%, 7%, 8%, or any value between 3-8%.

[0031] In an optional embodiment, the fineness of the spodumene ore powder is 200-325 mesh. The fineness of the spodumene concentrate ore powder directly affects its contact area with the leaching solution. The finer the ore powder, the larger the contact area with the leaching solution, thereby improving the leaching efficiency of the lithium element. Appropriate fineness can ensure that the lithium element is more fully dissolved in the acidic solution during the leaching process, thereby improving the productivity of lithium chloride.

[0032] Optionally, the fineness of the spodumene ore powder can be 200 mesh, 225 mesh, 250 mesh, 275 mesh, 300 mesh, or any value between 200 mesh and 325 mesh.

[0033] In an optional embodiment, the chlorination auxiliary agent includes a composite auxiliary agent composed of multiple chlorides and oxides such as calcium chloride, magnesium chloride, ammonium chloride, potassium chloride, sodium chloride and calcium oxide.

[0034] In an optional embodiment, the content of the spodumene ore powder is 50-70% based on the mass of the mixed material itself as 100%. Spodumene is the main raw material for preparing lithium chloride, and its consumption directly affects the productivity of lithium-containing solution. An appropriate amount of spodumene can ensure that the reaction is fully carried out, thereby improving the productivity of lithium-containing solution. The consumption of spodumene can affect the conditions such as temperature, time and pressure of the reaction. By controlling the consumption of spodumene, these reaction conditions can be optimized, making the reaction more efficient and stable, and making the reaction more efficient and stable. In addition, in the chlorination process, the impurities in the spodumene may enter the lithium-containing solution and affect the purity of the product. By reasonably controlling the consumption of spodumene in the chlorination auxiliary, the content of impurities can be reduced.

[0035] Optionally, the content of the spodumene ore powder in the mixture can be 50-70%.

[0036] In an optional embodiment, the ratio of the spodumene ore powder to the chlorination aid in the mixture is 1:1-2.5.

[0037] Optionally, the ratio of the spodumene ore powder to the chlorination auxiliary agent can be 1:1.08, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, or any value or any interval between 1:1-1.5.

[0038] In an optional embodiment, 3%-8% coke is added to the mixture and mixed with water to obtain the mixture pellets, and the particle size of the mixture pellets can be 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, or any value between 5-15mm.

[0039] In an optional embodiment, the calcination temperature is 900-1100° C. and the time is 2-5 hours. During the calcination process, a replacement reaction or a complex reaction can occur with the lithium element in the spodumene, promoting the release and migration of the lithium element. These reactions can be carried out at a lower temperature, so after adding the chlorination auxiliary agent, the temperature required for the entire calcination process is reduced.

[0040] Optionally, the calcination temperature may be 900°C, 920°C, 940°C, 960°C, 980°C, 1000°C, 1020°C, 1040°C, 1060°C, 1080°C, 1100°C, or any value between 900-1100°C; the calcination time may be 2 hours, 3 hours, 4 hours, 5 hours, or any value between 2-5 hours.

[0041] In an optional embodiment, the water leaching is carried out under the conditions of a liquid-to-solid ratio of 2-5 mL of water to 1 g of the spodumene ore powder, a leaching temperature of 80-90° C., a leaching time of 1-3 hours, and normal pressure.

[0042] In an optional embodiment, the extraction includes three-stage extraction, three-stage washing, and two-stage countercurrent stripping cleaning to obtain a lithium-containing solution.

[0043] The present application provides a method for preparing a lithium-containing solution, which is prepared by a method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent.

[0044] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0045] Example 1 This embodiment provides a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate. The preparation process is as follows: Figure 1 The detailed steps are as follows: (1) Spodumene with a lithium content of 3% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 200 mesh.

[0046] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder and calcium chloride, ammonium chloride, and magnesium chloride as a mixed aid are mixed in a ratio of 1:1 to obtain a mixture. The content of spodumene ore powder in the mixture is 50%.

[0047] (3) 8% coke and water are added to the mixture to obtain mixture pellets, and the particle size of the mixture pellets is 15 mm.

[0048] (4) The mixture was calcined in an oxygen atmosphere at 900° C. for 2 hours to obtain calcined sand.

[0049] (5) The roasted sand in step (4) is subjected to water leaching at a normal pressure with a solid-liquid ratio of 2 mL of water to 1 g of the spodumene ore powder, the leaching temperature is 70° C., and the leaching time is 2 hours to obtain a water leaching solution.

[0050] (6) The water infusion obtained in step (5) is subjected to three-stage extraction, three-stage washing, and two-stage countercurrent stripping to obtain a lithium-containing solution. The extract is cleaned by three-stage washing and two-stage countercurrent stripping. The solid-liquid mixture after water immersion is subjected to three-stage washing, with a liquid-solid ratio of 1g of the spodumene ore powder for every 4mL of water, and stirred for 30 minutes; the second-stage liquid-solid ratio is 1g of the spodumene ore powder for every 3mL of water, and stirred for 45 minutes; the third-stage liquid-solid ratio is 1g of the spodumene ore powder for every 2mL of water, and stirred for 60 minutes. Two-stage countercurrent stripping: hydrochloric acid is used in the first stage with a volume ratio of 1:1.5 and stirred for 20 minutes; the second stage has the same hydrochloric acid concentration and volume ratio, and the stirring time is extended to 30 minutes. The stripping solutions are combined for subsequent purification. The low-temperature transformation XRD spectrum of spodumene concentrate is as shown below. Figure 2 shown.

[0051] (7) The lithium-containing solution obtained in step (6) wherein Ca 2+ Less than 0.1g / L, Al 3+ Less than 0.1g / L, Mg 2+ Less than 0.1g / L, lithium recovery rate 97%.

[0052] Example 2 This embodiment provides a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate, and the detailed steps are as follows: (1) Spodumene with a lithium content of 5% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 300 mesh.

[0053] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder, calcium chloride and ammonium chloride are mixed in a ratio of 1:1.6 to obtain a mixture. The content of spodumene ore powder in the mixture is 60%.

[0054] (3) 8% coke and water are added to the mixture to obtain mixture pellets, and the particle size of the mixture pellets is 10 mm.

[0055] (4) The mixture was calcined in an oxygen atmosphere at 1000° C. for 3 hours to obtain calcined sand.

[0056] (5) The roasted sand in step (4) is immersed in water at a solid-liquid ratio of 2 mL of water to 1 g of the spodumene ore powder under normal pressure at a temperature of 80° C. for 3 hours to obtain an immersion liquid.

[0057] (6) The aqueous extract obtained in step (5) is subjected to three-stage extraction, three-stage washing, and two-stage countercurrent stripping to obtain a lithium-containing solution.

[0058] (7) The lithium-containing solution obtained in step (6) wherein Ca 2+ Less than 0.2g / L, Al 3+ Less than 0.2g / L, Mg 2+ Less than 0.3g / L, lithium recovery rate 95%.

[0059] Example 3 This embodiment provides a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate, and the detailed steps are as follows: (1) Spodumene with a lithium content of 8% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 325 mesh.

[0060] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder and a mixture of calcium chloride and calcium oxide are mixed in a ratio of 1:2.5 to obtain a mixture. The content of spodumene ore powder in the mixture is 70%.

[0061] (3) 3% coke and water are added to the mixture to obtain mixture pellets, and the particle size of the mixture pellets is 5 mm.

[0062] (4) The mixture was calcined in an oxygen atmosphere at 1100° C. for 5 hours to obtain calcined sand.

[0063] (5) The roasted sand in step (4) is immersed in water at a solid-liquid ratio of 5 mL of water to 1 g of the spodumene ore powder under normal pressure at a temperature of 90° C. for 3 hours to obtain an immersion liquid.

[0064] (6) The aqueous extract obtained in step (5) is subjected to three-stage extraction, three-stage washing, and two-stage countercurrent stripping to obtain a lithium-containing solution.

[0065] (7) The lithium-containing solution obtained in step (6) wherein Ca 2+ Less than 0.3g / L, Al 3+ Less than 0.2g / L, Mg 2+ Less than 0.3g / L, lithium recovery rate 93%.

[0066] Comparative Example 1 This comparative example provides a conventional method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent, and the detailed steps are as follows: (1) Spodumene with a lithium content of 3% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 220 mesh.

[0067] (2) Spodumene ore powder was roasted in an oxygen atmosphere at 1250° C. for 4 hours to obtain roasted sand.

[0068] (3) The roasted sand in step (2) is immersed in water at a solid-liquid ratio of 1 g of the spodumene ore powder per 1 mL of water under normal pressure, at a leaching temperature of 80° C. for 4 hours to obtain an immersion solution.

[0069] (4) The aqueous extract obtained in step (3) is subjected to four-stage extraction, four-stage washing, and four-stage stripping to obtain a lithium-containing solution.

[0070] (5) The lithium-containing solution obtained in step (5) wherein Ca 2+ Less than 0.5g / L, Al 3+ Less than 0.5g / L, Mg 2+ Less than 0.5g / L, lithium recovery rate 92%.

[0071] Comparative Example 2 This comparative example provides a conventional method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent, and the detailed steps are as follows: (1) Spodumene with a lithium content of 5% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 150 mesh.

[0072] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder and calcium chloride are mixed in a ratio of 1:3 to obtain a mixture. The content of spodumene ore powder in the mixture is 25%.

[0073] (3) 20% coke and water are added to the mixture to obtain mixture pellets, and the particle size of the mixture pellets is 30 mm.

[0074] (4) The mixture was calcined in an oxygen atmosphere at 1200° C. for 2 hours to obtain calcined sand.

[0075] (5) The roasted sand in step (4) is immersed in water at 85° C. for 3 hours at a solid-liquid ratio of 2 mL of water to 1 g of the spodumene ore powder under normal pressure to obtain an immersion liquid.

[0076] (6) The aqueous extract obtained in step (5) is subjected to secondary extraction, secondary washing, and secondary stripping to obtain a lithium-containing solution.

[0077] (7) The lithium-containing solution obtained in step (6) wherein Ca 2+ Less than 0.4g / L, Al 3+ Less than 0.4g / L, Mg 2+ Less than 0.4g / L, lithium recovery rate 90%.

[0078] Comparative Example 3 This comparative example provides a conventional method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent, and the detailed steps are as follows: (1) Spodumene with a lithium content of 7% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 200 mesh.

[0079] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder and calcium chloride are mixed in a ratio of 1:3.5 to obtain a mixture. The content of spodumene ore powder in the mixture is 25%.

[0080] (3) 2% coke and water are added to the mixture to obtain mixture pellets, and the particle size of the mixture pellets is 40 mm.

[0081] (4) The mixture was calcined in an oxygen atmosphere at 1200° C. for 4 hours to obtain calcined sand.

[0082] (5) The roasted sand in step (4) is immersed in water at a solid-liquid ratio of 2 mL of water to 1 g of the spodumene ore powder under normal pressure conditions at a temperature of 80° C. for 4 hours to obtain an immersion solution.

[0083] (6) The aqueous extract obtained in step (5) is subjected to secondary extraction, secondary washing, and secondary stripping to obtain a lithium-containing solution.

[0084] (7) The lithium-containing solution obtained in step (6) wherein Ca 2+ Less than 0.6g / L, Al 3+ Less than 0.6g / L, Mg 2+ Less than 0.6g / L, lithium recovery rate 85%.

[0085] Comparative Example 4 This comparative example provides a method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate, and the detailed steps are as follows: (1) Spodumene with a lithium content of 8% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 300 mesh.

[0086] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder and calcium chloride are mixed in a ratio of 1:1 to obtain a mixture. The content of spodumene ore powder in the mixture is 50%.

[0087] (3) 5% coke and water are added to the mixture to obtain mixture pellets, and the particle size of the mixture pellets is 15 mm.

[0088] (4) The mixture was calcined in an oxygen atmosphere at 600° C. for 3 hours to obtain calcined sand.

[0089] (5) The roasted sand in step (4) is immersed in water at a solid-liquid ratio of 2 mL of water to 1 g of the spodumene ore powder under normal pressure at a temperature of 85° C. for 3 hours to obtain an immersion solution.

[0090] (6) The water extract obtained in step (5) is subjected to four-stage extraction, four-stage washing, and four-stage stripping to obtain a lithium-containing solution and a washing solution.

[0091] (7) The lithium-containing solution obtained in step (6) wherein Ca 2+ Less than 0.7g / L, Al 3+ Less than 0.7g / L, Mg 2+ Less than 0.7g / L, lithium recovery rate 88%.

[0092] Comparative Example 5 This comparative example provides a method for preparing a lithium-containing solution by granulating and roasting spodumene concentrate with a low-temperature auxiliary agent, and the detailed steps are as follows: (1) Spodumene with a lithium content of 7% is used as raw material. The spodumene concentrate is crushed to obtain spodumene ore powder, and the fineness of the spodumene ore powder is 300 mesh.

[0093] (2) Calcium chloride is used as a chlorination aid. Spodumene ore powder and calcium chloride are mixed in a ratio of 1:1.5 to obtain a mixture. The content of spodumene ore powder in the mixture is 40%.

[0094] (3) 6% coke and water are added to the mixture to form pellets, and the particle size of the pellets is 12 mm.

[0095] (4) The mixture was calcined at 1400° C. for 2 hours in an oxygen atmosphere to obtain calcined sand.

[0096] (5) The roasted sand in step (4) is immersed in water at a solid-liquid ratio of 1 g of the spodumene ore powder to 3 mL of water under normal pressure at a temperature of 85° C. for 3 hours to obtain an immersion liquid.

[0097] (6) The aqueous extract obtained in step (5) is subjected to three-stage extraction, three-stage washing, and three-stage stripping to obtain a lithium-containing solution.

[0098] (7) The lithium-containing solution obtained in step (5) wherein Ca 2+ Less than 0.5g / L, Al 3+ Less than 0.5g / L, Mg 2+ Less than 0.5g / L, lithium recovery rate 92%.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these 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.

[0100] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate, characterized in that: include: The spodumene concentrate is crushed to obtain spodumene ore powder, and the spodumene ore powder is mixed with a chlorination aid to obtain a mixture; coke and water are added to prepare mixture pellets, and the mixture pellets are roasted to obtain roasted sand; the roasted sand is soaked in water, extracted, and purified to obtain a lithium-containing solution.

2. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: The lithium content in the spodumene concentrate is 3-8%.

3. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: The fineness of the spodumene ore powder is 200-325 meshes.

4. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: The chlorination auxiliary agent includes at least one of calcium chloride, magnesium chloride, ammonium chloride, potassium chloride, sodium chloride and calcium oxide.

5. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: Taking the mass of the mixture itself as 100%, the content of the spodumene ore powder is 50-70%.

6. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 5, characterized in that: The ratio of the spodumene ore powder to the chlorination auxiliary agent in the mixture is 1:0.8-1.

5.

7. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: 3%-8% coke is added to the mixture and mixed with water to obtain the mixture pellets, and the particle size of the mixture pellets is 5-15mm.

8. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: The calcination temperature is 900-1100°C and the calcination time is 2-5 hours.

9. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to claim 1, characterized in that: The water leaching is carried out at a liquid-to-solid ratio of 2-5 mL of water to 1 g of the spodumene ore powder, a leaching temperature of 60-90° C., a leaching time of 1-3 hours, and normal pressure.

10. The method for preparing a lithium-containing solution by low-temperature roasting of spodumene concentrate according to any one of claims 1 to 9, characterized in that: The extraction comprises: the extract is subjected to three-stage extraction, three-stage washing and two-stage countercurrent stripping to obtain a lithium-containing solution.

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