Comprehensive utilization method of lithium-containing clay ore

Abstract

The invention belongs to the technical field of comprehensive utilization of resources, and particularly relates to a comprehensive utilization method of lithium-containing clay ore. The comprehensive utilization method of the lithium-containing clay ore comprises the steps of pretreatment of the lithium-containing clay ore, leaching, concentration, purification and impurity removal, lithium precipitation, porous mullite preparation and the like, and by means of the comprehensive utilization method of the lithium-containing clay ore, battery-grade lithium carbonate, high-purity potassium sulfate and porous mullite can be obtained; the comprehensive utilization value and the lithium recovery rate of the lithium-containing clay ore are improved, and the method is suitable for large-scale popularization and application and high in application value.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of resources, and specifically relates to a comprehensive utilization method of lithium-containing clay ore. Background Art

[0002] The main lithium-containing ores in nature include lithium mica, spodumene, lithium feldspar, lithium porcelain stone, etc. These ores are raw materials for extracting metallic lithium. In addition, salt lake brine lithium ore is also an important lithium resource. It is the most common form of lithium resources, and its development level is far lower than that of lithium ore. In recent years, a new type of clay-type lithium ore has been gradually discovered and recognized in southwest my country. If this type of clay-type ore can be efficiently developed and utilized, it will effectively alleviate the shortage of lithium resources in my country.

[0003] At present, the main technologies for extracting lithium from lithium-containing ores are sulfate roasting, sulfuric acid roasting, limestone roasting, etc. These processes are mainly suitable for lithium in spodumene and lepidolite. The lithium in lithium-containing clay ores is present in clay minerals, has low grade and is rich in aluminum, so it is not suitable to directly use the above processes for lithium extraction.

[0004] In view of the above situation, it is urgent to develop a new technology that is effective and can comprehensively utilize lithium-containing clay ores for lithium extraction.

[0005] To this end, the present invention is proposed. Summary of the invention

[0006] The main purpose of the present invention is to propose a comprehensive utilization method of lithium-containing clay ore. By using the comprehensive utilization method of lithium-containing clay ore in the present invention, battery-grade lithium carbonate, high-purity potassium sulfate and porous mullite can be obtained, thereby improving the comprehensive utilization value and lithium recovery rate of the lithium-containing clay ore, being suitable for large-scale promotion and application, and having high application value.

[0007] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0008] The present invention provides a comprehensive utilization method of lithium-containing clay ore, which comprises the following steps:

[0009] Pre-treating the lithium-containing clay ore to obtain a pre-treated material;

[0010] The pretreated material is subjected to leaching treatment and first solid-liquid separation treatment to obtain a leaching solution and a leaching residue; the leaching residue contains alumina and silicon dioxide;

[0011] The leachate is subjected to a first concentration treatment and a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue; the first filter residue contains sodium sulfate and potassium sulfate;

[0012] Purifying and removing impurities from the first filtrate to obtain a second filtrate and a second filter residue; the second filter residue contains sodium sulfate;

[0013] The second filtrate is subjected to lithium precipitation treatment to obtain a mother liquor and lithium carbonate;

[0014] The leached residue and the second filter residue are used as raw materials for sintering to obtain porous mullite.

[0015] In some embodiments of the present invention, the pretreatment comprises:

[0016] Crushing the lithium-containing clay ore to obtain lithium clay powder;

[0017] The lithium clay powder is mixed with cellulose powder and sulfuric acid solution and then calcined to obtain the pretreated material.

[0018] In some embodiments of the present invention, the particle size of the lithium clay powder is 100 mesh to 200 mesh.

[0019] In some embodiments of the present invention, based on the mass of the lithium clay powder, the mass percentage of the cellulose powder is 0.2wt% to 1.5wt%; and / or,

[0020] The liquid-to-solid ratio of the sulfuric acid solution to the lithium clay powder is 0.8 mL / g to 2.0 mL / g; and / or,

[0021] The concentration of the sulfuric acid solution is 65% to 98%.

[0022] In some embodiments of the present invention, the roasting process is carried out in stages, including:

[0023] In the first stage, the temperature is raised to 180°C to 300°C at a heating rate of 3°C / min to 8°C / min, and the reaction is kept at this temperature for 0.5h to 8h;

[0024] In the second stage, the temperature is raised to 800°C to 900°C at a heating rate of 3°C / min to 8°C / min, and the reaction is kept at this temperature for 0.5h to 4h;

[0025] In the third stage, the temperature is lowered to 20°C to 30°C at a cooling rate of 3°C / min to 8°C / min to obtain the pretreated material.

[0026] In some embodiments of the present invention, the tail gas generated during the roasting process is recovered to produce sulfuric acid.

[0027] In some embodiments of the present invention, the leaching liquid of the leaching treatment is selected from deionized water, the leaching temperature is 25°C to 90°C, the time is not less than 2h, and the liquid-to-solid ratio is 3mL / g to 6mL / g.

[0028] In some embodiments of the present invention, the purification and impurity removal process includes:

[0029] The pH value of the first filtrate is adjusted to 4-5 and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2; the filter residue 2 contains aluminum hydroxide; and

[0030] The pH value of the filtrate 2 is adjusted to 10-12 and a fourth solid-liquid separation process is performed to obtain a filtrate 3 and a filter residue 3; the filter residue 3 contains magnesium hydroxide;

[0031] The filtrate 3 is subjected to a second concentration treatment and a fifth solid-liquid separation treatment to obtain the second filtrate and the second filter residue.

[0032] In some embodiments of the present invention, an alkaline solution is used to adjust the pH value of the first filtrate and the filtrate 2; and / or,

[0033] After the second concentration treatment, the lithium ion concentration in the second filtrate is not less than 10 g / L.

[0034] In some embodiments of the present invention, the alkaline solution is selected from sodium hydroxide solution.

[0035] In some embodiments of the present invention, the lithium precipitation process comprises:

[0036] Adding disodium ethylenediaminetetraacetate to the second filtrate to perform a first reaction treatment, and a sixth solid-liquid separation treatment to obtain a filtrate 5 and a filter residue 5;

[0037] Sodium carbonate is added to the filtrate 5 to carry out a second reaction treatment, a seventh solid-liquid separation treatment and a washing treatment to obtain the mother liquor and the lithium carbonate.

[0038] In some embodiments of the present invention, the mother liquor is transferred to the second filtrate of the next batch for cyclic lithium precipitation and evaporation and crystallization to obtain potassium sulfate.

[0039] In some embodiments of the present invention, the first reaction treatment time is 30 min to 2 h; and / or,

[0040] The temperature of the second reaction treatment is 80°C to 90°C and the time is 30min to 2h; and / or,

[0041] The molar ratio of calcium ions in the second filtrate to disodium ethylenediaminetetraacetate is 1:1.1 to 1:1.4; and / or,

[0042] The molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate is 1:1 to 1:1.4.

[0043] In some embodiments of the present invention, based on 100 parts by weight of the leached residue, the sintering process uses the following raw materials in parts by weight: 100 parts of leached residue, 20 to 25 parts of corundum, 35 to 60 parts of the second filter residue, 2 to 5 parts of lignin, and 1 to 2.5 parts of graphite; and / or,

[0044] The sintering process includes: ball-milling the raw materials to mix them evenly, heating them to 750°C to 1000°C at a heating rate of 3°C / min to 10°C / min, and keeping the temperature for 3h to 6h to obtain the porous mullite.

[0045] Compared with the prior art, the present invention achieves the following technical effects:

[0046] The comprehensive utilization method of lithium-containing clay ore in the present invention realizes the selective extraction of lithium, aluminum, silicon, potassium and other substances, and can obtain battery-grade lithium carbonate, high-purity potassium sulfate and porous mullite, thereby improving the comprehensive utilization value and lithium recovery rate of lithium-containing clay ore, being suitable for large-scale promotion and application, and having high application value.

[0047] In the comprehensive utilization method of the present invention, the tail gas generated in the roasting process can be recycled to produce sulfuric acid, and the sulfuric acid can be repeatedly mixed and utilized.

[0048] The leached residue obtained in the comprehensive utilization method of the present invention is environmentally friendly and harmless. The leached residue contains substances such as aluminum and silicon and can be used as a raw material for producing mullite. Titanium dioxide can be used as an auxiliary agent for sintering mullite, effectively reducing the sintering temperature and reducing energy consumption in production.

[0049] The comprehensive utilization method of the present invention contains fewer impurities in the leachate, so that the aluminum element that is easy to form gel is separated from the lithium element in the form of leaching residue. The lithium element is basically not lost during the concentration, enrichment, purification and refining of the leachate, thereby achieving a high recovery rate of lithium.

[0050] In the comprehensive utilization method of the present invention, basically no waste is generated in the whole process, and comprehensive utilization of all elements is achieved.

[0051] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0053] Figure 1The present invention is a process flow chart of a comprehensive utilization method of lithium-containing clay ore according to some embodiments of the present invention. DETAILED DESCRIPTION

[0054] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0056] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0057] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0058] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0059] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0060] In the present invention, the term "solid-liquid separation treatment" refers to a treatment method for achieving separation of solids and liquids, which may be but is not limited to gravity sedimentation, filtration, centrifugal sedimentation, etc., and can be flexibly selected according to actual needs.

[0061] The present invention provides a comprehensive utilization method of lithium-containing clay ore, which comprises the following steps:

[0062] Pre-treating the lithium-containing clay ore to obtain a pre-treated material;

[0063] The pretreated material is subjected to leaching treatment and first solid-liquid separation treatment to obtain a leaching solution and a leaching residue; the leaching residue contains alumina and silicon dioxide;

[0064] The leachate is subjected to a first concentration treatment and a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue; the first filter residue contains sodium sulfate and potassium sulfate;

[0065] Purifying and removing impurities from the first filtrate to obtain a second filtrate and a second filter residue; the second filter residue contains sodium sulfate;

[0066] The second filtrate is subjected to lithium precipitation treatment to obtain a mother liquor and lithium carbonate;

[0067] The leaching residue and the second filter residue are used as raw materials for sintering to obtain porous mullite.

[0068] The present invention provides a method for effectively utilizing lithium, aluminum, silicon and potassium from lithium-containing clay ore. The method comprises the steps of pretreatment, leaching, concentration, purification and impurity removal, lithium precipitation, porous mullite preparation and the like of the lithium-containing clay ore, and battery-grade lithium carbonate, high-purity potassium sulfate and porous mullite can be obtained, thereby improving the comprehensive utilization value and lithium recovery rate of the lithium-containing clay ore, being suitable for large-scale promotion and application, and having high application value.

[0069] Preprocessing

[0070] In the present invention, the lithium-containing clay ore is pretreated to obtain a pretreated material.

[0071] In some embodiments of the present invention, the pretreatment includes: crushing the lithium-containing clay ore to obtain lithium clay powder; and mixing the lithium clay powder with cellulose powder and sulfuric acid solution and then calcining to obtain a pretreated material.

[0072] In an embodiment of the present invention, the lithium-containing clay ore is crushed to facilitate the subsequent reaction to proceed fully.

[0073] In some embodiments of the present invention, the crushing process may use, but is not limited to, a jaw crusher, a roller mill, or a ball mill, and screening may be performed using a sieve with a corresponding mesh number.

[0074] In some embodiments of the present invention, the particle size of the lithium clay powder is 100-200 mesh. For example, the particle size of the lithium clay powder can be one of 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh, or any value satisfying the above range.

[0075] In some embodiments of the present invention, lithium clay powder is mixed with cellulose powder and sulfuric acid solution and calcined. During the aging calcination, the cellulose powder gradually decomposes and then releases a large amount of gas, which makes the sintered material loose, prevents the acidification calcination from compacting, and increases the contact area between the material and the air, so that it is heated evenly and promotes the aging calcination.

[0076] In some embodiments of the present invention, after lithium clay powder and cellulose powder are evenly mixed, sulfuric acid solution is added, stirred evenly, and calcined. The calcination changes its structure, facilitates subsequent processing, and can remove impurities.

[0077] In some embodiments of the present invention, based on the mass of the lithium clay powder, the mass percentage of the cellulose powder is 0.2wt% to 1.5wt%. For example, the mass percentage of the cellulose powder can be 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt% or any value satisfying the above range.

[0078] In some embodiments of the present invention, the acid used in the roasting treatment is selected from sulfuric acid, and the concentration of the sulfuric acid solution is 65% to 98%. For example, the concentration of the sulfuric acid solution can be one of 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, or any value that meets the above range.

[0079] In some embodiments of the present invention, the liquid-to-solid ratio of the sulfuric acid solution to the lithium clay powder is 0.8 mL / g to 2.0 mL / g. Exemplarily, the liquid-to-solid ratio can be 0.8 mL / g, 0.9 mL / g, 1.0 mL / g, 1.1 mL / g, 1.2 mL / g, 1.3 mL / g, 1.4 mL / g, 1.5 mL / g, 1.6 mL / g, 1.7 mL / g, 1.8 mL / g, 1.9 mL / g, 2.0 mL / g or any value satisfying the above range.

[0080] In some embodiments of the present invention, the roasting process is carried out in stages, specifically including:

[0081] The first stage of aging and calcining treatment is to heat up to 180°C to 300°C at a heating rate of 3°C / min to 8°C / min, and react at a constant temperature for 0.5h to 8h. For example, the heating rate can be one of 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, or any value satisfying the above range value. The sintering temperature can be one of 180°C, 190°C, 200°C, 220°C, 240°C, 250°C, 260°C, 280°C, 300°C, or any value satisfying the above range value. The reaction time can be one of 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, or any value satisfying the above range value.

[0082] The second stage is a high temperature calcination treatment, with a heating rate of 3°C / min to 8°C / min to 800°C to 900°C, and a constant temperature reaction for 0.5h to 4h. For example, the heating rate can be one of 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, or any value satisfying the above range. The sintering temperature can be one of 800°C, 850°C, 900°C, or any value satisfying the above range. The reaction time can be one of 0.5h, 1h, 2h, 3h, 4h, or any value satisfying the above range.

[0083] In the third stage, the temperature is lowered to room temperature at a cooling rate of 3°C / min to 8°C / min to obtain a pretreated material. For example, the cooling rate may be one of 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, or any value satisfying the above range. The room temperature may be 20°C to 30°C, specifically, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, or any value satisfying the above range.

[0084] In the present invention, the lithium clay powder is aged and roasted, and the mineral structure is destroyed. The metal components react with sulfuric acid to form corresponding metal sulfates. After high-temperature roasting, some metal sulfates are decomposed, such as aluminum sulfate and iron sulfate, to form metal oxides, which is convenient for subsequent treatment such as water leaching to achieve separation of aluminum, iron, silicon and lithium.

[0085] In some embodiments of the present invention, the tail gas generated during the roasting process, such as aging roasting and high-temperature roasting, can be recovered to produce sulfuric acid, and the produced sulfuric acid solution can be reused for mixing and sample preparation, thereby realizing the recycling of sulfuric acid.

[0086] Leaching treatment

[0087] In the present invention, the pre-treated material is subjected to leaching treatment and first solid-liquid separation treatment to obtain leaching solution and leaching residue, thereby separating substances such as lithium, aluminum, iron, silicon, sodium and potassium through leaching treatment.

[0088] In some embodiments of the present invention, the leachate of the leaching treatment is selected from deionized water, and the liquid-to-solid ratio is 3mL / g to 6mL / g. As the temperature of the leaching treatment increases, the leaching rate of substances such as aluminum, silicon and iron is higher. When the temperature of the leaching treatment is 25°C to 90°C and the time is not less than 2h, the leaching effect is better. Exemplarily, the temperature of the leaching treatment can be one of 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or any value that satisfies the above range value. The leaching time can be one of 2h, 3h, 4h or any value that satisfies the above range value. The liquid-to-solid ratio in the leaching treatment can be one of 3mL / g, 4mL / g, 5mL / g, 6mL / g or any value that satisfies the above range value. The inventors obtained the above-mentioned preferred leaching conditions through a large number of experiments, which helps to separate substances such as lithium, aluminum and iron, reduce impurities interfering with subsequent separation, reduce lithium losses, and improve lithium recovery.

[0089] In some embodiments of the present invention, a leachate and a leaching residue are obtained through a first solid-liquid separation process, the main components of the leaching residue are aluminum oxide and silicon dioxide, and the leaching residue is dried and recovered.

[0090] First concentration treatment

[0091] In the present invention, the leachate is subjected to a first concentration treatment and a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue.

[0092] In some embodiments of the present invention, the leachate is concentrated and enriched once or multiple times using a rotary evaporator.

[0093] In some embodiments of the present invention, a first filtrate and a first filter residue are obtained through the second solid-liquid separation process, and the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0094] Purification and removal

[0095] In the present invention, the first filtrate is purified and impurities removed to obtain a second filtrate and a second filter residue, thereby achieving the separation of aluminum, magnesium, sodium and other substances.

[0096] In some embodiments of the present invention, the purification and impurity removal process includes: adding an alkaline solution to the first filtrate to adjust the pH value of the first filtrate to 4-5, performing a third solid-liquid separation process, and obtaining a filtrate 2 and a filter residue 2. The main component of the filter residue 2 is aluminum hydroxide, thereby achieving the separation of aluminum substances.

[0097] In the filtrate 2, an alkaline solution is added to adjust the pH value of the filtrate 2 to 10-12, such as adjusting the pH value of the filtrate 2 to 10-11 or 11-12. Specifically, the pH value can be adjusted to one of 10, 11, or 12 or any value satisfying the above range, and the fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3. The main component of the filter residue 3 is magnesium hydroxide. Thus, the separation of magnesium substances is achieved.

[0098] The filtrate 3 is subjected to a second concentration treatment using a rotary evaporator, for example, the filtrate 3 is concentrated once or multiple times, and a fifth solid-liquid separation treatment is performed to obtain a second filtrate and a second filter residue, wherein the second filter residue contains sodium sulfate.

[0099] In some embodiments of the present invention, the alkaline solution may be, but is not limited to, a sodium hydroxide solution.

[0100] In some embodiments of the present invention, after the second concentration treatment, the lithium ion concentration in the second filtrate is not less than 10 g / L, thereby achieving lithium enrichment.

[0101] Lithium precipitation treatment

[0102] In the present invention, the second filtrate is subjected to lithium precipitation treatment to obtain mother liquor and lithium carbonate, thereby achieving separation of lithium carbonate. The lithium carbonate obtained in this step is crude lithium carbonate, which can be further purified by recrystallization and carbonization to obtain high-purity battery-grade lithium carbonate.

[0103] In the embodiment of the present invention, the lithium precipitation process includes: adding disodium ethylenediaminetetraacetate to the second filtrate for a first reaction process, and a sixth solid-liquid separation process to obtain a filtrate 5 and a filter residue 5, thereby achieving separation of calcium substances.

[0104] Sodium carbonate is added to the filtrate 5 to carry out the second reaction treatment, the seventh solid-liquid separation treatment and the washing treatment to obtain mother liquor and lithium carbonate, thereby obtaining crude lithium carbonate.

[0105] In some embodiments of the present invention, the molar ratio of calcium ions to disodium ethylenediaminetetraacetate in the second filtrate is 1:1.1 to 1:1.4, and disodium ethylenediaminetetraacetate (EDTA-2Na) is added, and the reaction is stirred for 30min to 2h. Exemplarily, the molar ratio of calcium ions to disodium ethylenediaminetetraacetate can be one of 1:1.1, 1:1.2, 1:1.3, 1:1.4, or any value that satisfies the above range value. The stirring reaction time can be one of 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, or any value that satisfies the above range value.

[0106] In some embodiments of the present invention, the molar ratio of lithium ions to sodium ions in sodium carbonate in the filtrate 5 is 1:1 to 1:1.4, sodium carbonate is added, the reaction is stirred at 80°C to 90°C for 30min to 2h, filtered and separated, and washed to obtain a mother liquor containing potassium and sodium ions and crude lithium carbonate. The crude lithium carbonate is thus obtained. Exemplarily, the molar ratio of lithium ions to sodium ions in sodium carbonate can be one of 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or any value that satisfies the above range value. The reaction temperature can be one of 80°C, 85°C, 90°C or any value that satisfies the above range value. The reaction time can be one of 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min or any value that satisfies the above range value.

[0107] In some embodiments of the present invention, the crude lithium carbonate obtained by the seventh solid-liquid separation is subjected to a washing treatment, and the washing liquid may be, but is not limited to, deionized water, and the temperature of the washing liquid may be the same as the temperature of the second reaction treatment, such as washing with hot water at 80° C. to 90° C. Exemplarily, the temperature of the washing liquid may be one of 80° C., 85° C., 90° C., or any value that satisfies the above range.

[0108] In the embodiment of the present invention, the mother liquor obtained after lithium precipitation contains relatively high potassium ions. After appropriate circulation and enrichment of the mother liquor, it can be evaporated and crystallized to obtain a potassium sulfate product.

[0109] In some embodiments of the present invention, since the mother liquor is rich in potassium and sodium ions, the mother liquor can be transferred to the second filtrate for cyclic lithium precipitation. For example, after the mother liquor is circulated for three lithium precipitation operations, it is evaporated and crystallized to precipitate potassium sulfate.

[0110] Preparation of mullite

[0111] In the present invention, the leached residue and the second filter residue are used as raw materials and subjected to sintering treatment to obtain porous mullite.

[0112] The main components of the leached residue are alumina, silicon dioxide, and a small amount of titanium dioxide, magnesium oxide, and calcium oxide. The second filter residue contains sodium sulfate. Titanium dioxide, magnesium oxide, calcium oxide, and sodium sulfate are used as additives in sintering mullite, which can effectively reduce the sintering temperature.

[0113] In some embodiments of the present invention, based on 100 parts by weight of the leached residue, the sintering process uses the following parts by weight of each raw material: 100 parts of leached residue, 20 to 25 parts of corundum, 35 to 60 parts of the second filter residue, 2 to 5 parts of lignin, and 1 to 2.5 parts of graphite. Exemplarily, the weight of corundum can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or any value that satisfies the above range value. The weight of the second filter residue can be 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, or any value that satisfies the above range value. The weight percentage of lignin can be 2 parts, 3 parts, 4 parts, 5 parts or any value satisfying the above range. The weight percentage of graphite can be 1 part, 1.5 parts, 2 parts, 2.5 parts or any value satisfying the above range.

[0114] In some embodiments of the present invention, the raw materials of the sintering treatment are ball-milled and mixed uniformly, and the temperature is increased to 750°C to 1000°C at a heating rate of 3°C / min to 10°C / min, and the temperature is kept for 3h to 6h to obtain porous mullite. Exemplarily, the heating rate can be one of 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, or any value satisfying the above range value. The sintering temperature can be one of 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, or any value satisfying the above range value. The holding time can be one of 3h, 4h, 5h, 6h, or any value satisfying the above range value.

[0115] In some embodiments of the present invention, the frequency of the ball mill used in the ball milling process is 30 Hz to 50 Hz, and the ball milling time is 3 min to 10 min. For example, the frequency of the ball mill can be one of 30 Hz, 35 Hz, 40 Hz, 45 Hz, 50 Hz, or any value satisfying the above range. The ball milling time can be one of 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or any value satisfying the above range.

[0116] In some embodiments of the present invention, the comprehensive utilization method of lithium-containing clay ore comprises the following steps:

[0117] The lithium-containing clay ore is pretreated to obtain a pretreated material.

[0118] The pretreated material is subjected to leaching treatment and a first solid-liquid separation treatment to obtain a leaching solution and leaching residue.

[0119] The leachate is subjected to a first concentration treatment and a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue.

[0120] The first filtrate is purified and impurities are removed, including: in the first filtrate, an alkaline solution is added to adjust the pH value of the first filtrate to 4-5, and a third solid-liquid separation process is performed to obtain filtrate 2 and filter residue 2. In filtrate 2, an alkaline solution is added to adjust the pH value of filtrate 2 to 10-12, and a fourth solid-liquid separation process is performed to obtain filtrate 3 and filter residue 3. The filtrate 3 is subjected to a second concentration process using a rotary evaporator, and a fifth solid-liquid separation process is performed to obtain a second filtrate and a second filter residue.

[0121] The second filtrate is subjected to lithium precipitation treatment, including: adding disodium ethylenediaminetetraacetate to the second filtrate for a first reaction treatment, and a sixth solid-liquid separation treatment to obtain a filtrate 5 and a filter residue 5. Sodium carbonate is added to the filtrate 5 for a second reaction treatment, and a seventh solid-liquid separation treatment and a washing treatment to obtain a mother liquor and crude lithium carbonate.

[0122] The leaching residue and the second filter residue are used as raw materials for sintering to obtain porous mullite.

[0123] The chemical reagents used in the specification and examples of the present invention include any conventional models or types in the art, and the present invention does not impose any special limiting requirements.

[0124] In the following embodiments, the raw ore used is lithium-containing chlorite clay ore, the main minerals of which are lithium chlorite, illite, etc. The main chemical elements of the raw ore are shown in Table 1. Figure 1 .

[0125] Table 1 Multi-element analysis of raw ore

[0126] element / % <![CDATA[Li2O]]> <![CDATA[Al2O3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Fe2O3]]> content 0.895 32.512 5.111 0.840 1.209 element / % CaO MgO <![CDATA[TiO2]]> <![CDATA[SiO2]]> content 0.240 1.166 1.091 33.375

[0127] Example 1

[0128] (1) Weigh 100g of 100-mesh ore, add 0.7g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 0.9mL / g, the concentration of the sulfuric acid solution is 98%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 250℃ at a rate of 5℃ / min, and react at a constant temperature for 3h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 8℃ / min, react at a constant temperature for 4h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0129] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 5 mL / g, and the mixture was stirred at 60° C. for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0130] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and sodium potassium sulfate.

[0131] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0132] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-12, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0133] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0134] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0135] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.4, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate is used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0136] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0137] (10) Based on 100 parts by weight of the leached residue, 20 parts of corundum, 45 parts of the second filter residue, 3 parts of lignin, and 2 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 30 Hz, the ball milling time was 9 min, and the temperature was increased to 1000 °C at a heating rate of 5 °C / min, and the temperature was kept for 3 h to obtain porous mullite.

[0138] Example 2

[0139] (1) Weigh 100g of 100-mesh ore, add 0.4g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.4mL / g, the concentration of the sulfuric acid solution is 70%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 200℃ at a rate of 5℃ / min, and react at a constant temperature for 4h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 8℃ / min, react at a constant temperature for 4h, and then cool to room temperature at a rate of 5℃ / min to obtain pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0140] (2) Deionized water was added to the pretreated material at a liquid-to-solid ratio of 5 mL / g, and the mixture was stirred at 30° C. for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0141] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0142] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0143] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 11-12, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0144] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0145] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0146] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.2, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0147] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0148] (10) Based on 100 parts by weight of the leached residue, 20 parts of corundum, 50 parts of the second filter residue, 3 parts of lignin, and 1.5 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 30 Hz, the ball milling time was 10 min, and the temperature was increased to 800 °C at a heating rate of 5 °C / min, and the temperature was kept for 5 h to obtain porous mullite.

[0149] Example 3

[0150] (1) Weigh 100g of 100-mesh ore, add 0.2g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.8mL / g, the concentration of the sulfuric acid solution is 65%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 300℃ at a rate of 5℃ / min, and react at a constant temperature for 1h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 900℃ at a rate of 8℃ / min, react at a constant temperature for 4h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0151] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 5 mL / g, and the mixture was stirred at 80°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0152] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0153] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0154] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 11-12, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0155] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0156] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.2 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0157] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.1, and the mixture is stirred and reacted at 90° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 90° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0158] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0159] (10) Based on 100 parts by weight of the leached residue, 20 parts of corundum, 55 parts of the second filter residue, 5 parts of lignin, and 2 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 30 Hz, and the ball milling time was 7 min. The temperature was increased to 750 °C at a heating rate of 5 °C / min and kept at this temperature for 6 h to obtain porous mullite.

[0160] Example 4

[0161] (1) Weigh 100g of 200-mesh ore, add 0.8g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.8mL / g, the concentration of the sulfuric acid solution is 65%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 180℃ at a rate of 5℃ / min, and react at a constant temperature for 8h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 900℃ at a rate of 5℃ / min, react at a constant temperature for 3h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0162] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 3 mL / g, and the mixture was stirred at 40°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0163] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0164] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0165] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-11, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0166] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0167] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.2 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0168] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.3, and the mixture is stirred and reacted at 90° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 90° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0169] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0170] (10) Based on 100 parts by weight of the leached residue, 20 parts of corundum, 60 parts of the second filter residue, 5 parts of lignin, and 2 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 40 Hz, the ball milling time was 4 min, and the temperature was increased to 900 °C at a heating rate of 3 °C / min, and the temperature was kept for 4 h to obtain porous mullite.

[0171] Example 5

[0172] (1) Weigh 100g of 100-mesh ore, add 1.5g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.1mL / g, the concentration of the sulfuric acid solution is 95%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 180℃ at a rate of 5℃ / min, and react at a constant temperature for 7h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 900℃ at a rate of 5℃ / min, react at a constant temperature for 3h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0173] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 3 mL / g, and the mixture was stirred at 40°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0174] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0175] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0176] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-11, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0177] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0178] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.4 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0179] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.4, and the mixture is stirred and reacted at 90° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 90° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0180] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0181] (10) Based on 100 parts by weight of the leached residue, 20 parts of corundum, 35 parts of the second filter residue, 2 parts of lignin, and 2.5 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 40 Hz, the ball milling time was 6 min, and the temperature was increased to 850 °C at a heating rate of 7 °C / min, and the temperature was kept for 5 h to obtain porous mullite.

[0182] Example 6

[0183] (1) Weigh 100g of 200-mesh ore, add 1.3g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 0.8mL / g, the concentration of the sulfuric acid solution is 70%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 250℃ at a rate of 3℃ / min, and react at a constant temperature for 5h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 5℃ / min, react at a constant temperature for 3h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0184] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 3 mL / g, and the mixture was stirred at 25°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0185] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0186] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0187] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-11, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0188] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0189] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.4 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0190] (8) Sodium carbonate is added at a molar ratio of 1:1 between lithium ions in the filtrate 5 and sodium ions in the sodium carbonate, and the mixture is stirred and reacted at 90° C. for 30 min, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 90° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0191] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0192] (10) Based on 100 parts by weight of the leached residue, 25 parts of corundum, 40 parts of the second filter residue, 2 parts of lignin, and 2.5 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 40 Hz, the ball milling time was 5 min, and the temperature was increased to 900 °C at a heating rate of 9 °C / min, and the temperature was kept for 3 h to obtain porous mullite.

[0193] Example 7

[0194] (1) Weigh 100g of 200-mesh ore, add 1.2g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.3mL / g, the concentration of the sulfuric acid solution is 90%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 300℃ at a rate of 3℃ / min, and react at a constant temperature for 0.5h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 5℃ / min, react at a constant temperature for 2h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0195] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 6 mL / g, and the mixture was stirred at 50° C. for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0196] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0197] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0198] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-11, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0199] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0200] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.1 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0201] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.3, and the mixture is stirred and reacted at 90° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 90° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0202] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0203] (10) Based on 100 parts by weight of the leached residue, 25 parts of corundum, 60 parts of the second filter residue, 4 parts of lignin, and 1 part of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 50 Hz, and the ball milling time was 3 min. The temperature was then increased to 1000 °C at a heating rate of 5 °C / min and kept at this temperature for 4 h to obtain porous mullite.

[0204] Example 8

[0205] (1) Weigh 100g of 200-mesh ore, add 0.5g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.6mL / g, the concentration of the sulfuric acid solution is 75%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 180℃ at a rate of 3℃ / min, and react at a constant temperature for 6h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 900℃ at a rate of 5℃ / min, react at a constant temperature for 2h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0206] (2) Deionized water was added to the pretreated material with a liquid-to-solid ratio of 6 mL / g, and the mixture was stirred at 90° C. for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0207] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0208] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0209] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-11, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0210] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0211] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.1 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0212] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.1, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0213] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0214] (10) Based on 100 parts by weight of the leached residue, 25 parts of corundum, 50 parts of the second filter residue, 4 parts of lignin, and 1.5 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 50 Hz, the ball milling time was 4 min, and the temperature was increased to 950 °C at a heating rate of 5 °C / min, and the temperature was kept for 3 h to obtain porous mullite.

[0215] Example 9

[0216] (1) Weigh 100g of 200-mesh ore, add 0.9g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.9mL / g, the concentration of the sulfuric acid solution is 70%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 250℃ at a rate of 8℃ / min, and react at a constant temperature for 2h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 3℃ / min, react at a constant temperature for 1h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0217] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 4 mL / g, and the mixture was stirred at 80°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0218] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0219] (4) Sodium hydroxide was added to the first filtrate to adjust the pH to 4-5, and a third solid-liquid separation process was performed to obtain filtrate 2 and filter residue 2.

[0220] (5) Sodium hydroxide was added to the filtrate 2 to adjust the pH to 10-11, and a fourth solid-liquid separation treatment was performed to obtain a filtrate 3 and a filter residue 3.

[0221] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0222] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0223] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.2, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0224] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0225] (10) Based on 100 parts by weight of the leached residue, 25 parts of corundum, 35 parts of the second filter residue, 4 parts of lignin, and 2.5 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 50 Hz, the ball milling time was 4 min, and the temperature was increased to 850 °C at a heating rate of 5 °C / min, and the temperature was kept for 4 h to obtain porous mullite.

[0226] Example 10

[0227] (1) Weigh 100g of 200-mesh ore, add 1.1g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.2mL / g, the concentration of the sulfuric acid solution is 90%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 200℃ at a rate of 8℃ / min, and react at a constant temperature for 3h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 900℃ at a rate of 3℃ / min, react at a constant temperature for 0.5h, and then cool to room temperature at a rate of 5℃ / min to obtain pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0228] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 4 mL / g, and the mixture was stirred at 70°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0229] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0230] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0231] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 10-11, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0232] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0233] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0234] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:4, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0235] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0236] (10) Based on 100 parts by weight of the leached residue, 25 parts of corundum, 40 parts of the second filter residue, 3 parts of lignin, and 1 part of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 30 Hz, the ball milling time was 8 min, and the temperature was increased to 800 °C at a heating rate of 10 °C / min, and the temperature was kept for 6 h to obtain porous mullite.

[0237] Comparative Example 1

[0238] (1) Weigh 100g of 100-mesh ore, add sulfuric acid solution at a liquid-ore ratio of 1.4mL / g, the concentration of the sulfuric acid solution is 70%, and stir evenly. Carry out the first stage of aging and roasting treatment, increase the temperature to 200℃ at a rate of 5℃ / min, and react at a constant temperature for 4h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 8℃ / min, react at a constant temperature for 4h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0239] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 5 mL / g, and the mixture was stirred at 30°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0240] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0241] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0242] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 11-12, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0243] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0244] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0245] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:2, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0246] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0247] (10) Based on 100 parts by weight of the leached residue, 20 parts of corundum, 50 parts of the second filter residue, 3 parts of lignin, and 1.5 parts of graphite were added, and the mixture was evenly mixed by ball milling. The ball milling frequency was 30 Hz, the ball milling time was 10 min, and the temperature was increased to 800 °C at a heating rate of 5 °C / min, and the temperature was kept for 5 h to obtain porous mullite.

[0248] Comparative Example 2

[0249] (1) Weigh 100g of 100-mesh ore, add 0.4g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.4mL / g, the concentration of the sulfuric acid solution is 70%, and stir well. Perform the first stage of aging and roasting treatment, increase the temperature to 200℃ at a rate of 5℃ / min, react at a constant temperature for 4h, and cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0250] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 5 mL / g, and the mixture was stirred at 30°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0251] (3) The leachate is subjected to a first concentration treatment multiple times using a rotary evaporator, and then subjected to a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of aluminum sulfate, sodium sulfate and potassium sulfate.

[0252] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0253] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 11-12, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0254] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0255] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0256] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.2, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0257] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0258] (10) Based on the weight of 100 parts of the leached residue, 20 parts of corundum, 50 parts of the second filter residue, 3 parts of lignin, and 1.5 parts of graphite were added and mixed evenly by ball milling. The ball mill frequency was 30 Hz, the ball milling time was 10 min, and the temperature was increased to 800 °C at a heating rate of 5 °C / min and kept warm for 5 h. No porous mullite was obtained.

[0259] Comparative Example 3

[0260] (1) Weigh 100g of 100-mesh ore, add 0.4g of cellulose powder, mix well, add sulfuric acid solution at a liquid-ore ratio of 1.4mL / g, the concentration of the sulfuric acid solution is 70%, and stir well. Carry out the first stage of aging and roasting treatment, increase the temperature to 200℃ at a rate of 5℃ / min, and react at a constant temperature for 4h, then carry out the second stage of high-temperature roasting treatment, increase the temperature to 800℃ at a rate of 8℃ / min, react at a constant temperature for 4h, and then cool to room temperature at a rate of 5℃ / min to obtain a pretreated material. The tail gas during the roasting process can be recovered to make sulfuric acid and recycled.

[0261] (2) Deionized water was added to the pretreated material at a liquid-solid ratio of 5 mL / g, and the mixture was stirred at 30°C for 2 h. The leaching liquid and leaching residue were obtained by filtration. The leaching residue was sent to a drying station.

[0262] (3) using a rotary evaporator to perform a first concentration treatment on the leachate for multiple times, and then performing a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue, wherein the first filter residue contains a mixture of sodium sulfate and potassium sulfate.

[0263] (4) Sodium hydroxide is added to the first filtrate to adjust the pH value to 4-5, and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2.

[0264] (5) Sodium hydroxide is added to the filtrate 2 to adjust the pH value to 11-12, and a fourth solid-liquid separation treatment is performed to obtain a filtrate 3 and a filter residue 3.

[0265] (6) The filtrate 3 is subjected to a second concentration treatment multiple times using a rotary evaporator, and then subjected to a fifth solid-liquid separation treatment to obtain a second filtrate and a second filter residue.

[0266] (7) Disodium ethylenediaminetetraacetate was added at a molar ratio of calcium ions to disodium ethylenediaminetetraacetate of 1:1.3 in the second filtrate, and the mixture was stirred for reaction for 30 minutes. The sixth solid-liquid separation treatment was performed to obtain filtrate 5 and residue 5.

[0267] (8) Sodium carbonate is added at a molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate of 1:1.2, and the mixture is stirred and reacted at 80° C. for 30 minutes, and the seventh solid-liquid separation treatment is performed to obtain mother liquor and crude lithium carbonate, and the crude lithium carbonate is washed with hot water at 80° C. The crude lithium carbonate can be used to obtain battery-grade lithium carbonate by carbonization method or the like.

[0268] (9) The mother liquor is transferred to the second filtrate of the next batch to circulate lithium precipitation. After the mother liquor is circulated three times, it is evaporated and crystallized to precipitate potassium sulfate product.

[0269] (10) Based on the weight of leached residue as 100 parts, 20 parts of corundum, 3 parts of lignin, and 1.5 parts of graphite were added and mixed evenly by ball milling. The ball mill frequency was 30 Hz, the ball milling time was 10 min, and the temperature was increased to 800 °C at a heating rate of 5 °C / min and kept at this temperature for 5 h. However, no porous mullite was obtained.

[0270] The present invention characterized the porosity of the porous mullite prepared in the embodiment and the comparative example, and detected the lithium leaching rate and lithium recovery rate in the embodiment and the comparative example. The results are shown in Table 2.

[0271] The calculation method of lithium leaching rate is: the ratio of the total mass of lithium contained in the leachate to the total mass of lithium in the original ore, assuming that the total mass of lithium in the original ore is m1, and the total mass of lithium in the leachate obtained after leaching is m2, the lithium leaching rate = (m2 / m1)*100%.

[0272] The calculation method of lithium recovery rate is:

[0273] The ratio of the actual production output obtained from the input of a unit amount of raw materials to the theoretically calculated product output. Assuming that the total mass of lithium in the raw ore is m1, the total mass of lithium lost during the process of removing impurities and extracting lithium is m2, the lithium recovery rate = ((m1m2) / m1)*100%.

[0274] The porosity of mullite adopts the national standard GB / T 1966-1996 porous ceramic apparent porosity and bulk density test method.

[0275] Table 2 Lithium extraction results and mullite characterization in examples and comparative examples

[0276]

[0277] It can be seen from Table 2 that the comprehensive utilization method of lithium-containing clay ore in the embodiment of the present invention can realize the selective extraction of lithium, aluminum, silicon, potassium and other substances in lithium-containing clay ore, and obtain battery-grade lithium carbonate, high-purity potassium sulfate and porous mullite. Moreover, the comprehensive utilization method in the present invention has fewer impurities in the leachate obtained after leaching, so that the aluminum element that is easy to form a gel is separated from the lithium element in the form of leached slag, and the lithium element is basically not lost in the concentration, enrichment, purification and purification of the leachate, so as to achieve a high recovery rate of lithium. In addition, the leached slag contains aluminum and silicon substances, which can be used as raw materials for mullite, and titanium dioxide and sodium sulfate can be used as additives for sintering mullite, effectively reducing the sintering temperature and reducing energy consumption in production.

[0278] Compared with the embodiments of the present invention, in Comparative Example 1, since cellulose powder was not added during the sintering process of the lithium-containing clay ore for pretreatment, there was a certain degree of acidification and roasting caking, which affected the lithium leaching rate and the porosity of the obtained mullite. In Comparative Example 2, since the second stage of high-temperature sintering treatment was not performed during the sintering process of the lithium-containing clay ore for pretreatment, some metal sulfates were not decomposed. The most serious problem was that a large amount of aluminum ions entered the leachate, and the lithium was almost completely lost due to the generation of highly adsorbable amorphous aluminum hydroxide during impurity removal. In addition, because the proportion of silicon in the leached residue was too large, mullite could not be prepared normally. In Comparative Example 3, in the final preparation process of porous mullite, since the second filter residue was not added and the sodium sulfate raw material was lacking, a reaction temperature higher than 800°C was required, and thus porous mullite was not obtained.

[0279] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A comprehensive utilization method of lithium-containing clay ore, characterized in that: The comprehensive utilization method comprises the following steps: Pre-treating the lithium-containing clay ore to obtain a pre-treated material; The pretreated material is subjected to leaching treatment and first solid-liquid separation treatment to obtain a leaching solution and a leaching residue; the leaching residue contains alumina and silicon dioxide; The leachate is subjected to a first concentration treatment and a second solid-liquid separation treatment to obtain a first filtrate and a first filter residue; the first filter residue contains sodium sulfate and potassium sulfate; Purifying and removing impurities from the first filtrate to obtain a second filtrate and a second filter residue; the second filter residue contains sodium sulfate; The second filtrate is subjected to lithium precipitation treatment to obtain a mother liquor and lithium carbonate; The leached residue and the second filter residue are used as raw materials for sintering to obtain porous mullite.

2. The comprehensive utilization method of lithium-containing clay ore according to claim 1, characterized in that: The pre-processing comprises: Crushing the lithium-containing clay ore to obtain lithium clay powder; The lithium clay powder is mixed with cellulose powder and sulfuric acid solution and then calcined to obtain the pretreated material; Preferably, the particle size of the lithium clay powder is 100-200 mesh; Preferably, based on the mass of the lithium clay powder, the mass percentage of the cellulose powder is 0.2wt% to 1.5wt%; and / or, The liquid-to-solid ratio of the sulfuric acid solution to the lithium clay powder is 0.8 mL / g to 2.0 mL / g; and / or, The concentration of the sulfuric acid solution is 65% to 98%.

3. The comprehensive utilization method of lithium-containing clay ore according to claim 2, characterized in that: The roasting process is carried out in stages, including: In the first stage, the temperature is raised to 180°C to 300°C at a heating rate of 3°C / min to 8°C / min, and the reaction is kept at this temperature for 0.5h to 8h; In the second stage, the temperature is raised to 800°C to 900°C at a heating rate of 3°C / min to 8°C / min, and the reaction is kept at this temperature for 0.5h to 4h; In the third stage, the temperature is lowered to 20°C to 30°C at a cooling rate of 3°C / min to 8°C / min to obtain the pretreated material; Preferably, the tail gas generated during the roasting process is recovered to produce sulfuric acid.

4. The comprehensive utilization method of lithium-containing clay ore according to claim 1, characterized in that: The leaching liquid of the leaching treatment is selected from deionized water, the temperature of the leaching treatment is 25° C. to 90° C., the time is not less than 2 hours, and the liquid-to-solid ratio is 3 mL / g to 6 mL / g.

5. The comprehensive utilization method of lithium-containing clay ore according to claim 1, characterized in that: The purification and impurity removal process includes: The pH value of the first filtrate is adjusted to 4-5 and a third solid-liquid separation process is performed to obtain a filtrate 2 and a filter residue 2; the filter residue 2 contains aluminum hydroxide; and The pH value of the filtrate 2 is adjusted to 10-12 and a fourth solid-liquid separation process is performed to obtain a filtrate 3 and a filter residue 3; the filter residue 3 contains magnesium hydroxide; The filtrate 3 is subjected to a second concentration treatment and a fifth solid-liquid separation treatment to obtain the second filtrate and the second filter residue.

6. The comprehensive utilization method of lithium-containing clay ore according to claim 5, characterized in that: Using an alkaline solution to adjust the pH value of the first filtrate and the filtrate 2; and / or, After the second concentration treatment, the lithium ion concentration in the second filtrate is not less than 10 g / L; Preferably, the alkaline solution is selected from sodium hydroxide solution.

7. The comprehensive utilization method of lithium-containing clay ore according to claim 1, characterized in that: The process of lithium precipitation treatment includes: Adding disodium ethylenediaminetetraacetate to the second filtrate to perform a first reaction treatment, and a sixth solid-liquid separation treatment to obtain a filtrate 5 and a filter residue 5; Sodium carbonate is added to the filtrate 5 to carry out a second reaction treatment, a seventh solid-liquid separation treatment and a washing treatment to obtain the mother liquor and the lithium carbonate.

8. The comprehensive utilization method of lithium-containing clay ore according to claim 1 or 7, characterized in that: The mother liquor is transferred to the second filtrate of the next batch for cyclic lithium precipitation and evaporation and crystallization to obtain potassium sulfate.

9. The comprehensive utilization method of lithium-containing clay ore according to claim 7, characterized in that: The first reaction treatment time is 30min to 2h; and / or, The temperature of the second reaction treatment is 80°C to 90°C and the time is 30min to 2h; and / or, The molar ratio of calcium ions in the second filtrate to disodium ethylenediaminetetraacetate is 1:1.1 to 1:1.4; and / or, The molar ratio of lithium ions in the filtrate 5 to sodium ions in the sodium carbonate is 1:1 to 1:1.

4.

10. The comprehensive utilization method of lithium-containing clay ore according to claim 1, characterized in that: Based on 100 parts by weight of the leached residue, the sintering process uses the following raw materials in parts by weight: 100 parts of leached residue, 20 to 25 parts of corundum, 35 to 60 parts of the second filter residue, 2 to 5 parts of lignin, and 1 to 2.5 parts of graphite; and / or, The sintering process includes: ball-milling the raw materials to mix them evenly, heating them to 750°C to 1000°C at a heating rate of 3°C / min to 10°C / min, and keeping the temperature for 3h to 6h to obtain the porous mullite.

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