Roasting additive and method for extracting lithium from lithium ore

Abstract

The invention relates to a roasting additive and a method for extracting lithium from lithium ore. The roasting additive comprises the following components: sulfate A, sodium sulfate and calcium carbonate, wherein the mass ratio of the sulfate A to the sodium sulfate to the calcium carbonate is (0.2-0.8): (0.1-0.9): (0.1-0.5); the sulfate A comprises at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

Description

Technical Field

[0001] The present application relates to the technical field of lithium ore extraction, and in particular to a roasting additive and a method for extracting lithium from lithium ore. Background Art

[0002] Secondary batteries such as lithium-ion batteries are increasingly widely used due to their clean and renewable characteristics. Among them, lithium-ion batteries are one of the most mature and widely used secondary batteries. Lithium-ion batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric cars and other fields.

[0003] Lithium-ion batteries mainly rely on the movement of lithium ions between the positive and negative electrodes to work, so the key raw material for preparing lithium-ion batteries is lithium salt. Lithium salts are usually extracted from lithium ores, and sulfate roasting methods are often used. The roasted clinker is crushed and then leached with water and filtered for solid-liquid separation to extract a lithium-containing solution. However, while obtaining a lithium-containing solution through a sulfate roasting method, a large amount of solid leaching residue is also obtained. In addition, because lithium ores such as lithium mica are usually associated with beryllium-containing minerals such as beryl and beryl, lithium mica also contains beryllium. After roasting, it mainly forms water-soluble beryllium-containing compounds. Beryllium and beryllium-containing compounds are highly toxic substances. On the one hand, they are easily soluble in lithium-containing solutions during leaching, thereby affecting the quality of the obtained lithium salts. On the other hand, some of them remain in the solid leaching residue. In the subsequent treatment or stacking process, soluble beryllium compounds are easily soluble in water, thereby endangering the ecological environment and the treatment cost is also high.

[0004] Therefore, the traditional technology still needs to be improved. Summary of the invention

[0005] The present application provides a roasting additive and a method for extracting lithium from lithium ore. The roasting additive or the method can fix beryllium element in the leaching residue after the lithium ore is roasted, thereby reducing its leaching amount in water.

[0006] In a first aspect of the present application, a roasting additive is provided, wherein the components of the roasting additive include sulfate A, sodium sulfate and calcium carbonate;

[0007] Wherein, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.8):(0.1-0.9):(0.1-0.5);

[0008] The sulfate A includes at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

[0009] The roasting additive contains specific components. When used for roasting lithium ore, sulfate A mainly reacts with lithium ore components to form lithium-containing sulfate, calcium carbonate mainly reacts with beryllium-containing substances in the lithium ore to form insoluble substances such as calcium beryllium fluoride, and sodium sulfate can form a solid solution with the converted soluble beryllium sulfate. In this way, all aspects cooperate, and after the lithium ore is roasted, the beryllium-containing substances in the lithium ore form insoluble substances or are wrapped by the solid solution and fixed in the leaching residue, so that the leaching of the beryllium-containing substances is reduced in the subsequent treatment process of the leaching residue, and the beryllium content in the lithium-containing solution is reduced.

[0010] The calcined additive satisfies any one of the following conditions (1) to (2):

[0011] (1) The mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.1-0.9):(0.15-0.5);

[0012] Optionally, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.1-0.5):(0.15-0.5);

[0013] (2) The mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.3-0.9):(0.1-T), and T satisfies: 0.1<T<0.15;

[0014] Optionally, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.3-0.5):(0.1-T).

[0015] The study found that calcium carbonate plays a major role in the fixation of beryllium-containing substances in lithium ore, and sodium sulfate synergistically fixes beryllium. Therefore, further regulating the lower limit of the ratio of calcium carbonate or increasing the lower limit of the ratio of sodium sulfate can significantly improve the beryllium fixation effect.

[0016] In some embodiments, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is 0.3:(0.1-0.5):(0.15-0.5).

[0017] Further adjust the distribution ratio of each group to improve the beryllium fixing effect.

[0018] In some embodiments, the sulfate A includes at least one of calcium sulfate and potassium sulfate.

[0019] Calcium sulfate and potassium sulfate have high roasting efficiency, which can improve the extraction efficiency of lithium; further, calcium sulfate is cheap, which can reduce costs.

[0020] In some of these embodiments, the roasting additive is used for roasting lithium ore.

[0021] A second aspect of the present application provides a method for extracting lithium from a lithium ore, comprising the following steps:

[0022] The lithium ore and the roasting additive of the first aspect are roasted to prepare clinker;

[0023] The clinker is placed in a leaching agent for immersion, solid-liquid separation is performed, and a lithium-containing solution and leached slag are prepared.

[0024] The above-mentioned method for extracting lithium from lithium ore adopts the roasting additive of the first aspect for roasting, wherein sulfate A mainly reacts with lithium ore components to form lithium-containing sulfate, calcium carbonate mainly reacts with beryllium-containing substances in the lithium ore to form insoluble calcium beryllium fluoride, and sodium sulfate can form a solid solution with the converted soluble beryllium sulfate. In this way, all aspects cooperate, and after the lithium ore is roasted, the beryllium-containing substances in the lithium ore form insoluble substances or are wrapped by the solid solution and fixed in the leaching residue, so that the leaching of beryllium-containing substances is reduced in the subsequent treatment process of the leaching residue, and the beryllium content in the lithium-containing solution is reduced.

[0025] The third aspect of the present application also provides a method for extracting lithium from a lithium ore, comprising the following steps:

[0026] The lithium ore and the roasting additive are roasted to prepare clinker;

[0027] The clinker is placed in a leaching agent for immersion, solid-liquid separation is performed, and a lithium-containing solution and leached slag are prepared.

[0028] The components of the roasting additive include sulfate A, sodium sulfate and calcium carbonate, and the mass ratio of the calcium carbonate in the roasting additive to the lithium ore is greater than or equal to 0.15; or

[0029] The mass ratio of the calcium carbonate in the roasting additive to the lithium ore is less than 0.15, and the mass ratio of the sodium sulfate in the roasting additive to the lithium ore is greater than or equal to 0.3;

[0030] Wherein, the sulfate A includes at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

[0031] In the above-mentioned method for extracting lithium from lithium ore, a roasting additive containing a specific component is used for roasting treatment, and the amount of calcium carbonate and sodium sulfate is controlled at the same time, and the lower limit of the mass ratio of calcium carbonate to lithium ore is regulated, or the lower limit of the mass ratio of sodium sulfate to lithium ore is regulated at the same time, which can significantly improve the beryllium fixation effect.

[0032] In some of the embodiments, the mass ratio of the lithium ore, the sulfate A, the sodium sulfate and the calcium carbonate is 1:(0.2-0.5):(0.1-0.9):(0.1-0.5).

[0033] In some embodiments, the calcination temperature is less than or equal to 1000°C;

[0034] Optionally, the calcination temperature is 900°C to 1000°C.

[0035] The temperature of the roasting treatment is further regulated to improve the roasting efficiency to release and extract as much lithium as possible, while promoting the formation of a solid solution between sodium sulfate and the converted beryllium sulfate, thereby further improving the beryllium solidification effect.

[0036] The lithium ore satisfies at least one of the following conditions (1) to (2):

[0037] (1) The lithium ore comprises at least one of lepidolite, lithium porcelain stone and lithium phosphate;

[0038] (2) The lithium ore contains beryllium;

[0039] Optionally, in the lithium ore, the mass proportion of beryllium oxide is 0.01% to 0.1%. DETAILED DESCRIPTION

[0040] The following is a detailed description of the embodiments of the technical solution of the present application. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0041] 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 this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "containing" in the specification and claims of this application and any variations thereof are intended to cover non-exclusive inclusions.

[0042] The "range" disclosed in the present application can be defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and any end value can be included or excluded independently, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a specific parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are also listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to listing the parameter as, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9 and 10.

[0043] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0044] 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 or implementation of the present application. The appearance of the phrase in various locations 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. The "implementation methods" mentioned herein have a similar understanding.

[0045] Those skilled in the art will appreciate that, in the methods of each embodiment or example, the order in which each step is written does not mean a strict order of execution and does not constitute any limitation on the implementation process, and the detailed order of execution of each step should be determined by its function and possible internal logic. If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) can be added to the method in any order, for example, the method may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0046] In the present application, in the open technical features or technical solutions described by the words "contain", "include", "comprises", etc., unless otherwise specified, additional members other than the listed members are not excluded, and it can be regarded as providing both closed features or solutions consisting of the listed members and open features or solutions including additional members other than the listed members.

[0047] In this application, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If there are multiple "options" in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "option" is independent.

[0048] In the present application, "room temperature" generally refers to 4°C to 30°C, preferably 20±5°C.

[0049] The traditional method of extracting lithium from lithium ore is mainly roasting. The roasting additives used in traditional technology are mainly sulfates. During the roasting process, lithium ions are separated from the insoluble lithium salts in the lithium ore to form soluble lithium salts.

[0050] Due to the complex composition of lithium ore, during the roasting process, while extracting lithium, a byproduct solid leaching residue with complex components will be produced. The solid leaching residue will contain highly toxic substances, such as soluble beryllium-containing substances. On the one hand, it is easy to dissolve in the lithium-containing solution during leaching, thereby affecting the quality of the obtained lithium salt. On the other hand, during the subsequent treatment or stacking of the solid leaching residue, the soluble beryllium compound is easily soluble in water, which harms the ecological environment. When testing the leaching toxicity of the body leaching residue produced by the traditional method of extracting lithium, the beryllium content in the leaching solution can reach a level higher than the hazardous waste limit value, which is a hazardous waste. However, the hazardous waste treatment capacity is very limited and the treatment cost is too high, which has caused great production pressure.

[0051] In some technologies, calcium hydroxide and other calcium-containing substances are added to the roasting additives to fix fluorine, and further research has found that calcium carbonate and sodium sulfate both have the effect of fixing beryllium. Based on this, the present application provides a roasting additive and a method for extracting lithium from lithium ore.

[0052] An embodiment of the present application provides a roasting additive, the components of which include sulfate A, sodium sulfate and calcium carbonate.

[0053] Among them, the mass ratio of sulfate A, sodium sulfate and calcium carbonate is (0.2-0.8):(0.1-0.9):(0.1-0.5).

[0054] The sulfate A includes at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

[0055] The roasting additive contains specific components. When used for roasting lithium ore, sulfate A mainly reacts with lithium ore components to form lithium-containing sulfate, calcium carbonate mainly reacts with beryllium-containing substances in the lithium ore to form insoluble calcium beryllium fluoride, and sodium sulfate can form a solid solution with the converted soluble beryllium sulfate. In this way, all aspects cooperate, and after the lithium ore is roasted, the beryllium-containing substances in the lithium ore form insoluble substances or are wrapped by the solid solution and fixed in the leaching residue, so that the leaching of the beryllium-containing substances is reduced in the subsequent treatment process of the leaching residue, and the beryllium content in the lithium-containing solution is reduced.

[0056] In some of these embodiments, the lithium ore contains fluorine.

[0057] The following is an example of the reaction process involved in the roasting process, taking the components Li2O·Al2O3·3SiO2 in lithium ore and sulfate A as potassium sulfate as an example, as follows:

[0058] Li2O·Al2O3·3SiO2+K2SO4→K2O·Al2O3·3SiO2+Li2SO4;

[0059] The fluorine in the lithium ore reacts with calcium carbonate to form solid calcium fluoride, which fixes the fluorine and, after a complex reaction during the roasting process, eventually forms insoluble substances such as calcium beryllium fluoride.

[0060] At the same time, beryllium sulfate and sodium sulfate undergo phase transformation to form a solid solution during the calcination process.

[0061] In the above “(0.2~0.8):(0.1~0.9):(0.1~0.5)”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and the following point values: 0.2:0.1:0.1, 0.2:0.2:0.1, 0.2:0.3:0.1, 0.2:0.4:0.1, 0.2:0.5:0.1, 0.2:0.6:0.1, 0.2:0.7:0.1, 0.2:0.8:0.1, 0.2:0.9:0.1, 0.2:0.1:0.2, 0.2:0.2:0.2, 0.2:0.3:0.2, 0.2:0.4:0.2, 0.2:0.5:0.2, 0.2:0.6:0.2, 0.2:0.7:0.2, 0.2:0.8:0.2, 0.2:0.9:0.2, 0.2:0.1:0.3, 0.2:0.2:0.3, 0.2:0.3:0.3, 0.2:0.4:0.3, 0.2:0.5:0.3, 0.2:0 .6:0.3, 0.2:0.7:0.3, 0.2:0.8:0.3, 0.2:0.9:0.3, 0.2:0.1:0.4, 0.2:0.2:0.4, 0.2:0.3:0.4, 0.2:0.4:0.4, 0.2:0.5:0.4, 0.2:0.6:0.4, 0.2:0.7:0. 4, 0.2:0.8:0.4, 0.2:0.9:0.4, 0.2:0.1:0.5, 0.2:0.2:0.5, 0.2:0.3:0.5, 0.2:0.4:0.5, 0.2:0.5:0.5, 0.2:0.6:0.5, 0.2:0.7:0.5, 0.2:0.8:0.5, 0.2 :0.9:0.5, 0.4:0.1:0.1, 0.4:0.2:0.1, 0.4:0.3:0.1, 0.4:0.4:0.1, 0.4:0.5:0.1, 0.4:0.6:0.1, 0.4:0.7:0.1, 0.4:0.8:0.1, 0.4:0.9:0.1, 0.4:0.1: 0.2, 0.4:0.2:0.2, 0.4:0.3:0.2, 0.4:0.4:0.2, 0.4:0.5:0.2, 0.4:0.6:0.2, 0.4:0.7:0.2, 0.4:0.8:0.2, 0.4:0.9:0.2, 0.4:0.1:0.3, 0.4:0.2:0.3, 0 .4:0.3:0.3, 0.4:0.4:0.3, 0.4:0.5:0.3, 0.4:0.6:0.3, 0.4:0.7:0.3, 0.4:0.8:0.3, 0.4:0.9:0.3, 0.4:0.1:0.4, 0.4:0.2:0.4, 0.4:0.3:0.4, 0.4:0.4:0.4、0.4:0.5:0.4、0.4:0.6:0.4、0.4:0.7:0.4、0.4:0.8:0.4、0.4:0.9:0.4、0.4:0.1:0.5、0.4:0.2:0.5、0.4:0.3:0.5、0.4:0.4:0.5、0.4:0.5:0.5、0.4:0.6:0.5、0.4:0.7:0.5、0.4:0.8:0.5、0.4:0.9:0.5、0.5:0.1:0.1、0.5:0.2:0.1、0.5:0.3:0.1、0.5:0.4:0.1、0.5:0.5:0.1、0.5:0.6:0.1、0.5:0.7:0.1、0.5:0.8:0.1、0.5:0.9:0.1、0.5:0.1:0.2、0.5:0.2:0.2、0.5:0.3:0.2、0.5:0.4:0.2、0.5:0.5:0.2、0.5:0.6:0.2、0.5:0.7:0.2、0.5:0.8:0.2、0.5:0.9:0.2、0.5:0.1:0.3、0.5:0.2:0.3、0.5:0.3:0.3、0.5:0.4:0.3、0.5:0.5:0.3、0.5:0.6:0.3、0.5:0.7:0.3、0.5:0.8:0.3、0.5:0.9:0.3、0.5:0.1:0.4、0.5:0.2:0.4、0.5:0.3:0.4、0.5:0.4:0.4、0.5:0.5:0.4、0.5:0.6:0.4、0.5:0.7:0.4、0.5:0.8:0.4、0.5:0.9:0.4、0.5:0.1:0.5、0.5:0.2:0.5、0.5:0.3:0.5、0.5:0.4:0.5、0.5:0.5:0.5、0.5:0.6:0.5、0.5:0.7:0.5、0.5:0.8:0.5、0.5:0.9:0.5、0.7:0.1:0.1、0.7:0.2:0.1、0.7:0.3:0.1、0.7:0.4:0.1、0.7:0.5:0.1、0.7:0.6:0.1、0.7:0.7:0.1、0.7:0.8:0.1、0.7:0.9:0.1、0.7:0.1:0.2、0.7:0.2:0.2、0.7:0.3:0.2、0.7:0.4:0.2、0.7:0.5:0.2、0.7:0.6:0.2、0.8:0.7:0.2、0.8:0.8:0.2、0.8:0.9:0.2、0.8:0.1:0.3、0.8:0.2:0.3、0.8:0.3:0.3、0.8:0.4:0.3、0.8:0.5:0.3、0.8:0.6:0.3, 0.8:0.7:0.3, 0.8:0.8:0.3, 0.8:0.9:0.3, 0.8:0.1:0.4, 0.8:0.2:0.4, 0.8:0.3:0.4, 0.8:0.4:0.4, 0.8:0.5:0.4, 0.8:0.6:0.4, 0.8:0.7:0.4, 0 .8:0.8:0.4, 0.8:0.9:0.4, 0.8:0.1:0.5, 0.8:0.2:0.5, 0.8:0.3:0.5, 0.8:0.4:0.5, 0.8:0.5:0.5, 0.8:0.6:0.5, 0.8:0.7:0.5, 0.8:0.8:0.5, 0.8: 0.9:0.5; or a range consisting of any two values, for example, it can be (0.2-0.8):(0.1-0.9):(0.1-0.5), (0.2-0.5):(0.1-0.9):(0.1-0.5), (0.3-0.8):(0.1-0.9):(0.1-0.5), (0.3-0.5):(0.1-0.9):(0.1-0.5), (0.2-0.4):(0.1-0.9):(0.1-0.5), (0.4-0.8):(0.1-0.9):(0.1-0.5), (0.2-0.8):(0.1-0.5):(0.1-0.5), (0.2-0.5): (0.1~0.5):(0.1~0.5), (0.3~0.8):(0.1~0.5):(0.1~0.5), (0.3~0.5):(0.1~0.5):(0.1~0.5), (0.2~0.4):(0.1~0.5):(0.1~0.5), (0.4~0.8):(0.1~0.5):(0.1~0.5), (0.2~0.8):(0.1~0.9):(0.15~0.5), (0.2~0.5):(0.1~0.9):(0.15~0.5), (0.3~0.8):(0.1~0.9):(0.15~0.5), (0.3~0.5):(0.1 ~0.9):(0.15~0.5), (0.2~0.4):(0.1~0.9):(0.15~0.5), (0.4~0.8):(0.1~0.9):(0.15~0.5), (0.2~0.8):(0.1~0.9):(2~0.5), (0.2~0.5):(0.1~0.9):(2~0.5), (0.3~0.8):(0.1~0.9):(2~0.5), (0.3~0.5):(0.1~0.9):(2~0.5), (0.2~0.4):(0.1~0.9):(2~0.5), (0.4~0.8):(0.1~0.9):(2~0.5). .

[0062] In some of the embodiments, the mass ratio of sulfate A, sodium sulfate and calcium carbonate is (0.2-0.5):(0.1-0.9):(0.15-0.5).

[0063] In some of the embodiments, the mass ratio of sulfate A, sodium sulfate and calcium carbonate is (0.2-0.5):(0.3-0.9):(0.1-T), and T satisfies: 0.1<T<0.15.

[0064] The study found that calcium carbonate plays a major role in the fixation of beryllium-containing substances in lithium ore, and sodium sulfate synergistically fixes beryllium. Therefore, further regulating the lower limit of the ratio of calcium carbonate or increasing the lower limit of the ratio of sodium sulfate can significantly improve the beryllium fixation effect.

[0065] In the above "0.1<T<0.15", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and the following point values: 0.11, 0.12, 0.13, 0.14, 0.145, 0.149; or a range consisting of any two numerical values, for example, it can be 0.11-0.12, 0.11-0.13, 0.11-0.14, 0.11-0.145, 0.11-0.149.

[0066] In some embodiments, the mass ratio of sulfate A, sodium sulfate and the calcium carbonate is (0.2-0.5):(0.1-0.5):(0.15-0.5).

[0067] In some embodiments, the mass ratio of sulfate A, sodium sulfate and the calcium carbonate is (0.2-0.5):(0.3-0.5):(0.1-T).

[0068] Further adjust the distribution ratio of each group to improve the beryllium fixing effect.

[0069] In some embodiments, the mass ratio of sulfate A, sodium sulfate and calcium carbonate is 0.3:(0.1-0.5):(0.15-0.5).

[0070] In the above “0.3:(0.1~0.5):(0.15~0.5)”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 0.3:0.1:0.15, 0.3:0.2:0.15, 0.3:0.3:0.15, 0.3:0.4:0.15, 0.3:0 .5:0.15, 0.3:0.2:0.2, 0.3:0.3:0.2, 0.3:0.4:0.2, 0.3:0.5:0.2, 0.3:0.2:0.3, 0.3:0.3:0.3, 0.3:0.4:0.3, 0.3:0.5:3, 0.3:0.2:0.4, 0.3:0.3:0.4, 0.3:0.4:0.4, 0.3:0.5: 0.4, 0.3:0.2:0.5, 0.3:0.3:0.5, 0.3:0.4:0.5, 0.3:0.5:0.5; or a range consisting of any two values, for example, 0.3:0.2:(0.15-0.5), 0.3:0.3:(0.15-0.5), 0.3:0.4:(0.15-0.5), 0.3:0.5:(0.15-0.5 )、0.3:0.2:(0.2~0.5), 0.3:0.3:(0.2~0.5), 0.3:0.4:(0.2~0.5), 0.3:0.5:(0.2~0.5), 0.3:0.2:(0.3~0.5), 0.3:0.3:(0.3~0.5), 0.3:0.4:(0.3~0.5), 0.3:0.5:(0.3~0.5).

[0071] In some embodiments, sulfate A includes at least one of calcium sulfate and potassium sulfate.

[0072] Calcium sulfate and potassium sulfate have high roasting efficiency, which can improve the extraction efficiency of lithium; further, calcium sulfate is cheap, which can reduce costs.

[0073] Furthermore, sulfate A may be any one of calcium sulfate and potassium sulfate, or may be a mixture of calcium sulfate and potassium sulfate.

[0074] Optionally, sulfate A includes a mixture of calcium sulfate and potassium sulfate, and the mass ratio of calcium sulfate to potassium sulfate can be any ratio; further, the mass ratio of calcium sulfate to potassium sulfate can be (1-9):(1-9).

[0075] In one embodiment of the present application, a method for extracting lithium from lithium ore is provided, comprising the following steps S11 to S12.

[0076] Step S11, roasting the lithium ore and the roasting additive of the first aspect to prepare clinker.

[0077] Step S12, immersing the clinker in a leaching agent, separating the solid and the liquid, and preparing a lithium-containing solution and leached residue.

[0078] The above-mentioned method for extracting lithium from lithium ore adopts the roasting additive of the first aspect for roasting, wherein sulfate A mainly reacts with lithium ore components to form lithium-containing sulfate, calcium carbonate mainly reacts with beryllium-containing substances in the lithium ore to form insoluble calcium beryllium fluoride, and sodium sulfate can form a solid solution with the converted soluble beryllium sulfate. In this way, all aspects cooperate, and after the lithium ore is roasted, the beryllium-containing substances in the lithium ore form insoluble substances or are wrapped by the solid solution and fixed in the leaching residue, so that the leaching of beryllium-containing substances is reduced in the subsequent treatment process of the leaching residue, and the beryllium content in the lithium-containing solution is reduced.

[0079] Another embodiment of the present application provides a method for extracting lithium from lithium ore, comprising the following steps S21 to S22.

[0080] Step S21: roasting the lithium ore and the roasting additive to prepare clinker;

[0081] Step S22: immersing the clinker in a leaching agent, separating the solid from the liquid, and preparing a lithium-containing solution and leached residue.

[0082] The components of the roasting additive include sulfate A, sodium sulfate and calcium carbonate, and the mass ratio of the calcium carbonate in the roasting additive to the lithium ore is greater than or equal to 0.15.

[0083] Or, the mass ratio of the calcium carbonate in the roasting additive to the lithium ore is less than 0.15, and the mass ratio of the calcium carbonate in the roasting additive to the lithium ore is greater than or equal to 0.3.

[0084] Wherein, sulfate A includes at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

[0085] In the above-mentioned method for extracting lithium from lithium ore, a roasting additive containing a specific component is used for roasting treatment, and the amount of calcium carbonate and sodium sulfate is controlled at the same time, and the lower limit of the mass ratio of calcium carbonate to lithium ore is regulated, or the lower limit of the mass ratio of sodium sulfate to lithium ore is regulated at the same time, which can significantly improve the beryllium fixation effect.

[0086] In some of the embodiments, the mass ratio of lithium ore, sulfate A, sodium sulfate and calcium carbonate is 1:(0.2-0.5):(0.1-0.9):(0.1-0.5).

[0087] In some of the embodiments, the mass ratio of lithium ore, sulfate A, sodium sulfate and calcium carbonate is 1:(0.2-0.5):(0.1-0.9):(0.15-0.5).

[0088] In some of the embodiments, the mass ratio of lithium ore, sulfate A, sodium sulfate and calcium carbonate is 1:(0.2-0.5):(0.3-0.9):(0.1-T), and T satisfies: 0.1<T<0.15.

[0089] The study found that calcium carbonate plays a major role in the fixation of beryllium-containing substances in lithium ore, and sodium sulfate synergistically fixes beryllium. Therefore, further regulating the lower limit of the ratio of calcium carbonate or increasing the lower limit of the ratio of sodium sulfate can significantly improve the beryllium fixation effect.

[0090] The value of T is the same as described above and will not be repeated here.

[0091] In some of the embodiments, the mass ratio of lithium ore, sulfate A, sodium sulfate and the calcium carbonate is 1:(0.2-0.5):(0.2-0.5):(0.15-0.5).

[0092] In some of the embodiments, the mass ratio of lithium ore, sulfate A, sodium sulfate and the calcium carbonate is 1:(0.2-0.5):(0.3-0.5):(0.1-T).

[0093] In some of the embodiments, the mass ratio of lithium ore, sulfate A, sodium sulfate and the calcium carbonate is 1:0.3:(0.2-0.5):(0.15-0.5).

[0094] In the above “1:0.3:(0.2~0.5):(0.15~0.5)”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 1:0.3:0.2:0.15, 1:0.3:0.3:0.15, 1:0.3:0.4:0.15, 1:0.3:0.5:0.15, 1:0.3:0. 2:0.2、1:0.3:0.3:0.2、1:0.3:0.4:0.2、1:0.3:0.5:0.2、1:0.3:0.2:0.3、1:0.3:0.3:0.3、1:0.3:0.4:0.3、1:0.3:0.5:3、1:0.3:0.2:0.4、1:0.3:0.3:0.4、1:0.3:0.4:0.4、1:0.3:0.5:0.4、1 :0.3:0.2:0.5, 1:0.3:0.3:0.5, 1:0.3:0.4:0.5, 1:0.3:0.5:0.5; or a range consisting of any two values, for example, it can be 1:0.3:0.2:(0.15~0.5), 1:0.3:0.3:(0.15~0.5), 1:0.3:0.4:(0.15~0.5), 1:0.3:0.5:(0.15~0.5), 1 :0.3:0.2:(0.2~0.5), 1:0.3:0.3:(0.2~0.5), 1:0.3:0.4:(0.2~0.5), 1:0.3:0.5:(0.2~0.5), 1:0.3:0.2:(0.3~0.5), 1:0.3:0.3:(0.3~0.5), 1:0.3:0.4:(0.3~0.5), 1:0.3:0.5:(0.3~0.5).

[0095] In some of the embodiments, the mass ratio of calcium carbonate in the roasting additive to lithium ore is 0.15 to 0.5.

[0096] In some of the embodiments, the mass ratio of sodium sulfate in the roasting additive to lithium ore is 0.1-0.9.

[0097] In some of the embodiments, in some of the embodiments, the mass ratio of sodium sulfate in the roasting additive to lithium ore is 0.2-0.5.

[0098] In some of the embodiments, the mass ratio of calcium carbonate in the roasting additive to lithium ore is 0.2-0.5.

[0099] In some of the embodiments, the mass ratio of calcium carbonate in the roasting additive to lithium ore is 0.3-0.5.

[0100] In some of the embodiments, the mass ratio of calcium carbonate in the roasting additive to lithium ore is less than 0.15 and greater than 0.1, and the mass ratio of sodium sulfate in the roasting additive to lithium ore is 0.3-0.9.

[0101] In some of the embodiments, the mass ratio of sodium sulfate in the roasting additive to lithium ore is 0.3-0.9.

[0102] In some of the embodiments, the mass ratio of sodium sulfate in the roasting additive to lithium ore is 0.3-0.5.

[0103] In some of the embodiments, the mass ratio of sulfate A in the roasting additive to lithium ore is 0.2-0.8.

[0104] In some of the embodiments, the mass ratio of sulfate A in the roasting additive to lithium ore is 0.2-0.5.

[0105] In some embodiments, the calcination temperature is less than or equal to 1000°C.

[0106] In some of the embodiments, the calcination temperature is 900°C to 1000°C.

[0107] The temperature of the roasting treatment is further regulated to improve the roasting efficiency to release and extract as much lithium as possible, while promoting the formation of a solid solution between sodium sulfate and the converted beryllium sulfate, thereby further improving the beryllium solidification effect.

[0108] In some examples, the calcination temperature is 930° C. to 980° C. Specifically, the calcination temperature includes, but is not limited to, 930° C., 935° C., 940° C., 945° C., 950° C., 955° C., 960° C., 965° C., 970° C., 975° C., 980° C., or a range between any two of the foregoing.

[0109] In some examples, in step S2, the calcination time is 0.5 h to 3 h. Specifically, the calcination time includes but is not limited to: 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h or a range between any two of the foregoing.

[0110] Without limitation, in step S2, the roasting process can be static roasting, or it can be roasting by conveying materials into a rotary kiln using a belt or the like. The rotary kiln has high thermal efficiency and heat treatment uniformity, is suitable for large-scale production requiring high temperature treatment, has large production capacity and high production efficiency.

[0111] There is no limitation. After the roasting treatment, the material can be cooled to room temperature naturally or by cooling means, such as a cooling kiln.

[0112] It can be understood that the lithium element in the above lithium-containing solution mainly exists in the form of lithium salt, mainly lithium sulfate.

[0113] In some of the embodiments, the leaching agent may be an aqueous solvent; specifically, it may be pure water or an aqueous solution of an inorganic acid; further, the aqueous solution of an inorganic acid may be a dilute sulfuric acid solution or a dilute hydrochloric acid solution.

[0114] In some of the embodiments, during the impregnation, the solid-liquid ratio of the clinker to the leaching agent is 1kg:(0.6-3)L.

[0115] Furthermore, after the leaching time reaches 2h to 24h, the leaching agent is replaced and the immersion steps are repeated until the residual amount of lithium oxide in the leached residue is detected to be less than 0.3wt%.

[0116] Furthermore, the lithium-containing solution can be used to prepare various lithium sources commonly used in lithium batteries. The specific method can adopt various conversion methods in the art. Here, lithium carbonate is taken as an example: the lithium-containing solution is precipitated with lime and soda ash, filtered to obtain the precipitate, and then reacted with a saturated soda ash solution to obtain lithium carbonate. After solid-liquid separation, lithium carbonate can be obtained.

[0117] In some of the examples, in step S11 or step S21, before mixing the lithium ore with the roasting additive, a step of drying the lithium ore is also included. It is understandable that some lithium ores, such as lithium mica, have a high moisture content, which is not conducive to uniform mixing with other raw materials, so drying can be performed first. Without limitation, drying can be performed in an oven or a drying kiln.

[0118] Without limitation, the temperature of the drying process is 200° C. to 300° C. Specifically, the temperature of the drying process includes, but is not limited to, 200° C., 210° C., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., 280° C., 290° C., 300° C., or a range between any two of the foregoing.

[0119] Without limitation, the water content (mass percentage) of the lithium ore after drying is ≤6%. Specifically, the water content of the lithium ore after drying includes but is not limited to: 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6% or a range between any two of the foregoing.

[0120] In some of the examples, in step S12 and step S22, the method of solid-liquid separation is not limited, and can be, for example, filtration, etc., and a circulating water vacuum pump can be used for filtration, or a belt filter can be used for filtration.

[0121] In some of these embodiments, the lithium ore contains beryllium.

[0122] Furthermore, in lithium ore, the beryllium element mainly exists in the form of beryllium oxide.

[0123] Optionally, in the lithium ore, the mass proportion of beryllium oxide is greater than or equal to 0.01%.

[0124] Optionally, in the lithium ore, the mass proportion of beryllium oxide is 0.01% to 0.1%.

[0125] In some embodiments, the mass percentage of lithium in the lithium ore is less than 3%. Specifically, the mass percentage of lithium in the lithium ore includes, but is not limited to, 0.1%, 0.5%, 1%, 1.2%, 1.5%, 1.7%, 2%, 2.2%, 2.5%, 2.7%, 3%, or a range between any two of the foregoing.

[0126] Without limitation, the lithium ore includes at least one of lepidolite, lithium porcelain stone and lithium phosphate.

[0127] In some examples, the lithium mineral includes lepidolite.

[0128] The present application will be described below in conjunction with specific embodiments, but the present application is not limited to the following embodiments. It should be understood that the attached claims summarize the scope of the present application. Under the guidance of the concept of the present application, technical personnel in the field should realize that certain changes made to the various embodiments of the present application will be covered by the spirit and scope of the claims of the present application.

[0129] The following are specific examples. Unless otherwise specified, the raw materials used in the examples are all commercially available products. The mass proportion of beryllium oxide in the lepidolite used in the examples is 0.04%.

[0130] Example 1

[0131] The specific steps are as follows:

[0132] (1) 300 g of dried lepidolite was mixed with a certain amount of a calcination additive and placed in a 500 mL evaporating dish, and calcined at 940° C. for 1 h to obtain a calcined clinker.

[0133] The roasting additive includes sulfate A, sodium sulfate and calcium carbonate in a mass ratio of K1, and the mass ratio of lithium mica to sulfate A, sodium sulfate and calcium carbonate in the roasting additive is recorded as K2. For details of sulfate A, K1 and K2, please see Table 1.

[0134] (2) The roasted clinker is cooled and then crushed, and the crushed clinker is ball-milled and impregnated with water at room temperature, and finally filtered to separate the solid leached residue and the lithium-containing solution. The solid-liquid ratio of clinker to water is 1kg:1L, and the impregnation time is 0.5h.

[0135] (3) Detection of beryllium content H in the leachate of the leached residue. The lower the beryllium content H, the better the beryllium fixation effect is, as follows:

[0136] The leaching residue is subjected to microwave digestion treatment in accordance with the Solid Waste Leaching Toxicity Method Sulfuric Acid and Nitric Acid Method (HJT 299-2007), and the leaching solution is subjected to microwave digestion treatment in accordance with Appendix S of the Solid Waste Identification Standard Hazardous Waste Identification Standard Leaching Toxicity Identification (GB5085.3-2007). The sample after microwave digestion is tested for beryllium content H in the leaching solution by ICP-MS and in accordance with Appendix B of the Solid Waste Identification Standard Hazardous Waste Identification Standard: Leaching Toxicity Identification (GB5085.3-2007). The necessary steps involved are as follows:

[0137] The moisture content of the leached residue was first detected by the loss on drying method to calculate the dry basis weight of the leached residue. Ultrapure water with a pH of about 3.25 was added according to a liquid-solid ratio of water to the dry basis weight of the leached residue of 10:1. The mixture was placed on a flip-type oscillation device and oscillated for 18±2h. The leached solution was then filtered with a filter membrane and subjected to microwave digestion for 0.7h. Finally, the beryllium content was detected by ICP-MS.

[0138] Please see Table 1 for specific results.

[0139] Embodiments 2 to 10

[0140] The present embodiments 2 to 10 are basically the same as the embodiment 1, and the only difference is that K1 and K2 are different from the embodiment 1. Please see Table 1 for details.

[0141] Other conditions are the same as in Example 1.

[0142] Comparative Example 1

[0143] Comparative Example 1 is substantially the same as Example 1, except that the calcium carbonate in the roasting agent of Example 1 is replaced by calcium hydroxide, and K1 is the mass ratio of sulfate A, sodium sulfate and calcium hydroxide, and K2 is the mass ratio of lepidolite to sulfate A, sodium sulfate and calcium hydroxide in the roasting additive. See Table 1 for details.

[0144] Other conditions are the same as in Example 1.

[0145] Comparative Example 2

[0146] Comparative Example 2 is basically the same as Example 1, except that K1 and K2 are different from Example 1. See Table 1 for details.

[0147] Other conditions are the same as in Example 1.

[0148] The parameters and test results of each embodiment and comparative example are shown in Table 1.

[0149] Table 1

[0150]

[0151] Among them, when the beryllium content H is "≤0.1μg / L" or "≤1μg / L", it means that the beryllium content in the leachate of the leached residue is low, which is lower than the lower limit that can be accurately detected. The numerical value fluctuates greatly during detection, and the maximum detected value is taken as the upper limit; "Not detected" means that the beryllium content in the leachate of the leached residue is extremely low, close to 0, and cannot be detected.

[0152] By analyzing the data in Table 1 and comparing the beryllium content results of Examples 1 to 10 and Comparative Examples 1 to 2, it can be seen that the roasting additive and method of the present application can fix the beryllium element in the leaching residue after the lithium ore is roasted, thereby reducing its leaching amount in water.

[0153] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0154] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A roasting additive, characterized in that: The components of the roasting additive include sulfate A, sodium sulfate and calcium carbonate; Wherein, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.8):(0.1-0.9):(0.1-0.5); The sulfate A includes at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

2. The roasting additive according to claim 1, characterized in that The calcined additive satisfies any one of the following conditions (1) to (2): (1) The mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.1-0.9):(0.15-0.5); Optionally, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.1-0.5):(0.15-0.5); (2) The mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.3-0.9):(0.1-T), and T satisfies: 0.1<T<0.15; Optionally, the mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is (0.2-0.5):(0.3-0.5):(0.1-T).

3. The roasting additive according to claim 1, characterized in that The mass ratio of the sulfate A, the sodium sulfate and the calcium carbonate is 0.3:(0.1-0.5):(0.15-0.5).

4. The roasting additive according to any one of claims 1 to 3, characterized in that The sulfate A includes at least one of calcium sulfate and potassium sulfate.

5. The roasting additive according to any one of claims 1 to 3, characterized in that The roasting additive is used for roasting lithium ore.

6. A method for extracting lithium from lithium ore, characterized in that: The steps include: Roasting the lithium ore and the roasting additive according to any one of claims 1 to 5 to prepare clinker; The clinker is placed in a leaching agent for immersion, solid-liquid separation is performed, and a lithium-containing solution and leached slag are prepared.

7. A method for extracting lithium from lithium ore, characterized in that: The steps include: The lithium ore and the roasting additive are roasted to prepare clinker; The clinker is placed in a leaching agent for immersion, solid-liquid separation, and lithium-containing solution and leached residue are prepared; The components of the roasting additive include sulfate A, sodium sulfate and calcium carbonate, and the mass ratio of the calcium carbonate in the roasting additive to the lithium ore is greater than or equal to 0.15; or The mass ratio of the calcium carbonate in the roasting additive to the lithium ore is less than 0.15, and the mass ratio of the sodium sulfate in the roasting additive to the lithium ore is greater than or equal to 0.3; Wherein, the sulfate A includes at least one of calcium sulfate, magnesium sulfate, ammonium sulfate and potassium sulfate.

8. The method for extracting lithium from lithium ore according to claim 6 or 7, characterized in that: The mass ratio of the lithium ore, the sulfate A, the sodium sulfate and the calcium carbonate is 1:(0.2-0.5):(0.1-0.9):(0.1-0.5).

9. The method for extracting lithium from lithium ore according to claim 6 or 7, characterized in that: The temperature of the calcination treatment is less than or equal to 1000°C; Optionally, the calcination temperature is 900°C to 1000°C.

10. The method for extracting lithium from lithium ore according to claim 6 or 7, characterized in that: The lithium ore satisfies at least one of the following conditions (1) to (2): (1) The lithium ore comprises at least one of lepidolite, lithium porcelain stone and lithium phosphate; (2) The lithium ore contains beryllium; Optionally, in the lithium ore, the mass proportion of beryllium oxide is 0.01% to 0.1%.

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