A method for selectively extracting lithium from a lithium-containing glass

Abstract

The application discloses a method for selectively extracting lithium from lithium-containing glass, which comprises the following steps: (1) crushing the lithium-containing glass to obtain lithium-containing glass powder; (2) mixing a roasting agent, a roasting auxiliary agent and the lithium-containing glass powder to obtain a mixture; (3) granulating and aging the mixture to obtain granulated material; roasting the granulated material to obtain roasted material; (4) crushing the roasted material, ball-milling and water leaching the crushed roasted material, and then performing solid-liquid separation to obtain water leaching liquid and water leaching residue; (5) adding an alkaline substance to the water leaching liquid to remove impurities, and then performing solid-liquid separation to obtain impurity-removed liquid and impurity-removed residue; (6) adding a carbonate to the impurity-removed liquid to remove calcium, and then performing solid-liquid separation to obtain calcium-removed liquid and calcium-removed residue; and the calcium-removed liquid is used for preparing battery-grade lithium carbonate. Through the specific use of the roasting agent and the roasting auxiliary agent, the lithium element in the lithium-containing glass can be selectively converted and leached under relatively mild process conditions.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology and relates to a method for selectively extracting lithium from lithium-containing glass. Background Technology

[0002] Lithium, known as "white petroleum," is a key metallic material for the development of strategic emerging industries such as new energy and new materials. With the continued surge in global demand for lithium resources, developing efficient, low-cost, and environmentally friendly lithium extraction technologies has become crucial for ensuring a stable supply of lithium resources and promoting the sustainable development of related industries. Currently, industrial lithium extraction processes and cutting-edge research methods for solid lithium-containing raw materials generally face common technical challenges such as poor lithium extraction selectivity, high energy consumption, and severe environmental pollution.

[0003] In existing technologies, methods for extracting lithium from mainstream solid lithium-containing raw materials include the sulfuric acid method, limestone sintering method, chlorination roasting method, and sulfate roasting method.

[0004] The sulfuric acid process requires first subjecting spodumene to a high-temperature crystal transformation treatment at approximately 1050℃, followed by roasting the transformed raw material with concentrated sulfuric acid at 250℃~300℃. Its core drawbacks are significant: firstly, the process has extremely high energy consumption and places stringent requirements on the strong acid corrosion resistance of the production equipment; secondly, for the widely abundant lepidolite ore, the roasting process releases large amounts of highly toxic hydrogen fluoride gas, resulting in high environmental end-of-pipe treatment costs; and thirdly, a large amount of impurities such as aluminum and iron in the ore dissolves, leading to a complex composition of the leaching solution system, a lengthy subsequent purification process, and ultimately a low overall lithium recovery rate.

[0005] The limestone sintering method involves mixing lithium-containing raw materials with limestone in a specific ratio and sintering at a high temperature of approximately 1000℃ to convert the lithium in the raw materials into water-soluble calcium lithiumate. However, the production process is energy-intensive, generates a large amount of waste residue after the sintering reaction, and the effective lithium content in the residue phase is low, resulting in poor process economics. Furthermore, impurities such as calcium, aluminum, and silicon dissolve simultaneously with lithium, severely reducing the selectivity of lithium extraction and increasing the difficulty of subsequent separation and purification.

[0006] The chlorination roasting method converts lithium in raw materials into volatile lithium chloride by adding chlorinating agents such as calcium chloride under high temperature conditions, thereby achieving lithium separation and collection. However, chlorinating agents have a significant corrosive effect on production equipment, and the recovery efficiency of volatile lithium salts is unstable. In addition, the roasting process poses an environmental risk of generating persistent organic pollutants such as dioxins, which greatly limits the industrial-scale promotion of this technology.

[0007] The sulfate roasting method uses sodium sulfate and potassium sulfate as roasting agents, and carries out the roasting reaction with lithium-containing raw materials under relatively low temperature conditions of 700–900℃.

[0008] Moreover, the methods provided by the aforementioned existing technologies suffer from poor extraction selectivity and excessive reagent consumption. For example, during the roasting process, the roasting agent not only reacts with the target component lithium but also with gangue components such as aluminum and silicon in the raw materials, generating soluble aluminum sulfate or double salts. This phenomenon directly leads to a high concentration of impurities such as aluminum and silicon in the water leachate, significantly increasing the difficulty of separating impurities from lithium and substantially increasing the cost and complexity of subsequent solution purification. In addition, to achieve a high lithium conversion rate, roasting agent far exceeding the stoichiometric ratio is usually required. Excessive roasting agent not only directly increases the cost of raw materials, but its residue in the waste residue or entering the leachate further increases the pressure on subsequent wastewater and waste residue treatment, bringing additional environmental costs.

[0009] Therefore, a method for selectively extracting lithium from lithium-containing glass is needed to ensure a high lithium recovery rate while effectively suppressing the leaching of impurities, thereby simplifying the subsequent purification process, reducing overall production costs, and achieving effective control of environmental pollution. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the present invention aims to provide a method for selectively extracting lithium from lithium-containing glass. This method can achieve highly selective conversion and leaching of lithium in lithium-containing glass under relatively mild process conditions, effectively suppressing the leaching of impurities while ensuring a high lithium recovery rate, thereby simplifying subsequent processes, reducing overall costs, and minimizing environmental pollution.

[0011] To achieve this objective, the present invention employs the following technical solution:

[0012] This invention provides a method for selectively extracting lithium from lithium-containing glass, the method comprising the following steps:

[0013] (1) Lithium-containing glass is crushed to obtain lithium-containing glass powder;

[0014] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0015] The calcining agent includes sodium sulfate and calcium sulfate;

[0016] The calcination aid includes any one or a combination of at least two of calcium oxide, calcium carbonate, or calcium fluoride.

[0017] (3) The mixture is granulated and aged to obtain granulated material; the granulated material is roasted to obtain roasted cooked material;

[0018] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0019] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0020] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0021] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0022] This invention employs a compound calcining agent of sodium sulfate and calcium sulfate, combined with calcining aids of calcium oxide and / or calcium carbonate. Through the specific combination of these agents, highly selective conversion and leaching of lithium from lithium-containing glass can be achieved under relatively mild process conditions. This technical solution ensures a high lithium recovery rate while effectively inhibiting the leaching of impurity components, thereby simplifying subsequent purification processes, reducing overall production costs, and mitigating environmental pollution. Furthermore, the lithium extraction method provided by this invention has good universality for lithium-containing glasses with different phase compositions, possessing advantages such as wide raw material adaptability and low raw material access requirements; it also enables selective water leaching recovery of lithium resources, fundamentally preventing the leaching of large amounts of aluminum and silicon impurities from lithium-containing glass. The granulation operation in the process effectively improves the calcination reaction efficiency, and the overall process is simple and operates stably and reliably.

[0023] In some embodiments, the lithium content in the lithium-containing glass in step (1) is 1.5wt% to 5.5wt%.

[0024] In some embodiments, the particle size of the lithium-containing glass powder in step (1) is <150 mesh.

[0025] In some embodiments, the mass of the sodium sulfate is 0.7 to 1 times that of the lithium-containing glass powder.

[0026] In some embodiments, the mass of the calcium sulfate is 0.75 to 1.5 times that of the lithium-containing glass powder.

[0027] In some embodiments, the mass of the calcination aid is 0.02 to 0.1 times that of the lithium-containing glass powder.

[0028] In some embodiments, the mass of water used in the wet mixing is 8% to 12% of the mass of the mixture.

[0029] In some embodiments, the granulation method in step (3) includes roller granulation.

[0030] In some embodiments, the granulated material obtained in step (3) is an ellipsoid with a major diameter of 2.8cm to 3.2cm and a minor diameter of 1.4cm to 1.6cm.

[0031] In some embodiments, the aging time in step (3) is 12h to 48h.

[0032] In some embodiments, the roasting temperature in step (3) is 830°C to 950°C.

[0033] In some embodiments, the roasting time in step (3) is 1h to 6h.

[0034] In some embodiments, the long diameter of the roasted clinker after crushing in step (4) is ≤0.5cm.

[0035] In some embodiments, the temperature of the ball mill water immersion in step (4) is 30°C to 60°C.

[0036] In some embodiments, the water immersion time for ball milling in step (4) is 0.5h to 4h;

[0037] In some embodiments, the liquid-to-solid ratio of the ball milling and water immersion in step (4) is 1:1 to 1:8, and the dimension of the liquid-to-solid ratio is mL / g.

[0038] In some embodiments, the alkaline substance in step (5) includes any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or calcium oxide.

[0039] In some embodiments, the pH value for impurity removal in step (5) is 12-13.

[0040] In some embodiments, the temperature for removing impurities in step (5) is 40°C to 90°C.

[0041] In some embodiments, the time for impurity removal in step (5) is 1h to 5h.

[0042] In some embodiments, the carbonate in step (6) includes sodium carbonate.

[0043] In some embodiments, the amount of carbonate used in step (6) is 2 to 5 times the theoretical amount.

[0044] In some embodiments, the temperature for calcium removal in step (6) is 25°C to 90°C.

[0045] In some embodiments, the calcium removal time in step (6) is 1h to 5h.

[0046] As a preferred embodiment of the method provided by the present invention, the method includes the following steps:

[0047] (1) The lithium-containing glass is crushed to obtain lithium-containing glass powder with a particle size of <150 mesh;

[0048] The lithium content in the lithium-containing glass is 1.5wt%~5.5wt%;

[0049] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0050] The calcining agent includes sodium sulfate and calcium sulfate;

[0051] The mass of the sodium sulfate is 0.7 to 1 times that of the lithium-containing glass powder;

[0052] The mass of the calcium sulfate is 0.75 to 1.5 times that of the lithium-containing glass powder;

[0053] The calcination aid includes any one or a combination of at least two of calcium oxide, calcium carbonate, or calcium fluoride.

[0054] The mass of the calcination aid is 0.02 to 0.1 times that of the lithium-containing glass powder;

[0055] The mass of water used in the wet mixing process is 8% to 12% of the mass of the mixture.

[0056] (3) The mixture is granulated and aged for 12h~48h to obtain granulated material; the granulated material is roasted at 830℃~950℃ for 1h~6h to obtain roasted clinker.

[0057] The granulation method includes roller granulation;

[0058] The granulated material obtained by granulation is an ellipsoid with a major diameter of 2.8cm to 3.2cm and a minor diameter of 1.4cm to 1.6cm.

[0059] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0060] The long diameter of the crushed roasted clinker is ≤0.5cm;

[0061] The ball milling water immersion temperature is 30℃~60℃, the time is 0.5h~4h, the liquid-solid ratio is 1:1~1:8, and the dimension of the liquid-solid ratio is mL / g;

[0062] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0063] The alkaline substance includes any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or calcium oxide;

[0064] The impurity removal process involves a pH value of 12-13, a temperature of 40℃-90℃, and a time of 1h-5h.

[0065] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0066] The carbonate includes sodium carbonate, and the amount of the carbonate used is 2 to 5 times the theoretical amount.

[0067] The calcium removal temperature is 25℃~90℃, and the time is 1h~5h;

[0068] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0069] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] This invention employs a compound calcining agent of sodium sulfate and calcium sulfate, combined with calcining aids of calcium oxide and / or calcium carbonate. Through the specific combination of these agents, highly selective conversion and leaching of lithium from lithium-containing glass can be achieved under relatively mild process conditions. This technical solution ensures a high lithium recovery rate while effectively inhibiting the leaching of impurity components, thereby simplifying subsequent purification processes, reducing overall production costs, and mitigating environmental pollution. Furthermore, the lithium extraction method provided by this invention has good universality for lithium-containing glasses with different phase compositions, possessing the advantages of wide raw material adaptability and low raw material access requirements; it also enables selective water leaching recovery of lithium resources, fundamentally preventing the leaching of large amounts of aluminum and silicon impurities from lithium-containing glass. Moreover, the granulation operation in the process effectively improves the calcination reaction efficiency, and the overall process is simple and operates stably and reliably. Attached Figure Description

[0072] Figure 1 A process flow diagram is provided for the method of this invention. Detailed Implementation

[0073] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0074] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0075] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0076] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0077] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0078] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0079] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0080] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0081] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0082] In this invention, "optional" means that something is optional, that is, it refers to either "with" or "without". If there are multiple "optional" options in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, then each "optional" option is independent.

[0083] This invention provides a method for selectively extracting lithium from lithium-containing glass, the method comprising the following steps:

[0084] (1) Lithium-containing glass is crushed to obtain lithium-containing glass powder;

[0085] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0086] The calcining agent includes sodium sulfate and calcium sulfate;

[0087] The calcination aid includes any one or a combination of at least two of calcium oxide, calcium carbonate, or calcium fluoride.

[0088] (3) The mixture is granulated and aged to obtain granulated material; the granulated material is roasted to obtain roasted cooked material;

[0089] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0090] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0091] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0092] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0093] This invention employs a compound calcining agent of sodium sulfate and calcium sulfate, combined with calcining aids of calcium oxide and / or calcium carbonate. Through the specific combination of these agents, highly selective conversion and leaching of lithium from lithium-containing glass can be achieved under relatively mild process conditions. This technical solution ensures a high lithium recovery rate while effectively inhibiting the leaching of impurity components, thereby simplifying subsequent purification processes, reducing overall production costs, and mitigating environmental pollution. Furthermore, the lithium extraction method provided by this invention has good universality for lithium-containing glasses with different phase compositions, possessing the advantages of wide raw material adaptability and low raw material access requirements; it also enables selective water leaching recovery of lithium resources, fundamentally preventing the leaching of large amounts of aluminum and silicon impurities from lithium-containing glass. Moreover, the granulation operation in the process effectively improves the calcination reaction efficiency, and the overall process is simple and operates stably and reliably.

[0094] In some embodiments, the lithium content in the lithium-containing glass in step (1) is 1.5wt% to 5.5wt%, for example, it can be 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt% or 5.5wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0095] In some embodiments, the particle size of the lithium-containing glass powder in step (1) is <150 mesh.

[0096] The particle size of the lithium-containing glass powder described in this invention is <150 mesh, meaning that the lithium-containing glass powder can pass through a 150-mesh sieve.

[0097] In some embodiments, the mass of sodium sulfate is 0.7 to 1 times that of the lithium-containing glass powder, for example, it can be 0.7, 0.8, 0.9 or 1 times, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0098] In some embodiments, the mass of the calcium sulfate is 0.75 to 1.5 times that of the lithium-containing glass powder, for example, it can be 0.75 times, 0.8 times, 0.85 times, 0.9 times, 1 time, 1.1 times, 1.2 times, 1.3 times, 1.4 times or 1.5 times, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0099] In some embodiments, the mass of the calcination aid is 0.02 to 0.1 times that of the lithium-containing glass powder, for example, it can be 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.1 times, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0100] In some embodiments, the mass of water used in the wet mixing is 8% to 12% of the mass of the mixture, for example, it can be 8%, 9%, 10%, 11% or 12%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0101] In some embodiments, the granulation method in step (3) includes roller granulation.

[0102] In some embodiments, the granulated material obtained in step (3) is an ellipsoid with a major diameter of 2.8cm to 3.2cm and a minor diameter of 1.4cm to 1.6cm.

[0103] The long diameter is 2.8cm to 3.2cm, for example, it can be 2.8cm, 2.9cm, 3cm, 3.1cm or 3.2cm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0104] The short diameter is 1.4cm to 1.6cm, for example, it can be 1.4cm, 1.45cm, 1.5cm, 1.55cm or 1.6cm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0105] In some embodiments, the aging time in step (3) is 12h to 48h, for example, it can be 12h, 18h, 24h, 30h, 36h, 42h or 48h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0106] In some embodiments, the roasting temperature in step (3) is 830°C to 950°C, for example, it can be 830°C, 850°C, 900°C or 950°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0107] In some embodiments, the roasting time in step (3) is 1h to 6h, for example, it can be 1h, 2h, 3h, 4h, 5h or 6h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0108] In some embodiments, the long diameter of the calcined clinker after crushing in step (4) is ≤0.5cm, for example, it can be 0.1cm, 0.2cm, 0.3cm, 0.4cm or 0.5cm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0109] In some embodiments, the temperature of the ball mill water immersion in step (4) is 30°C to 60°C, for example, it can be 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0110] In some embodiments, the ball milling water immersion time in step (4) is 0.5h to 4h, for example, it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0111] In some embodiments, the liquid-to-solid ratio of the ball milling and water immersion in step (4) is 1:1 to 1:8, and the dimension of the liquid-to-solid ratio is mL / g. The liquid-to-solid ratio is 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7 or 1:8, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0112] In some embodiments, the alkaline substance in step (5) includes any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or calcium oxide. Typical but non-limiting combinations include a combination of sodium hydroxide and calcium hydroxide, a combination of calcium hydroxide and calcium oxide, a combination of sodium hydroxide and calcium oxide, or a combination of sodium hydroxide, calcium hydroxide, and calcium oxide.

[0113] In some embodiments, the pH value for impurity removal in step (5) is 12 to 13, for example, it can be 12, 12.5 or 13, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0114] In some embodiments, the temperature for removing impurities in step (5) is 40°C to 90°C, for example, it can be 40°C, 50°C, 60°C, 70°C, 80°C or 90°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0115] In some embodiments, the time for removing impurities in step (5) is 1h to 5h, for example, it can be 1h, 2h, 3h, 4h or 5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0116] In some embodiments, the carbonate in step (6) includes sodium carbonate.

[0117] In some embodiments, the amount of carbonate used in step (6) is 2 to 5 times the theoretical amount, for example, it can be 2 times, 3 times, 4 times or 5 times, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0118] In this invention, the theoretical amount of carbonate refers to the amount of carbonate required to completely remove calcium.

[0119] In some embodiments, the temperature for calcium removal in step (6) is 25°C to 90°C, for example, it can be 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C or 90°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0120] In some embodiments, the calcium removal time in step (6) is 1h to 5h, for example, it can be 1h, 2h, 3h, 4h or 5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0121] In some embodiments, the method for using the calcium-removed liquid to prepare battery-grade lithium carbonate includes: the calcium-removed liquid is subjected to conventional extraction for lithium extraction, sodium carbonate precipitation for lithium, and carbonation pyrolysis in sequence to obtain battery-grade lithium carbonate, and the lithium precipitation mother liquor is recycled for extraction for lithium extraction.

[0122] In some embodiments, the method for preparing battery-grade lithium carbonate from the calcium-removed liquid includes: the calcium-removed liquid undergoes conventional alkaline extraction to extract lithium, then the pH of the back-extraction solution is adjusted to 10, 1.1 times the theoretical amount of sodium carbonate is added, and lithium is precipitated at 90°C to obtain crude lithium carbonate; battery-grade lithium carbonate is obtained through carbonization pyrolysis, and the lithium precipitation mother liquor is reused for extraction to extract lithium.

[0123] As a preferred embodiment of the method provided by the present invention, the method includes the following steps:

[0124] (1) The lithium-containing glass is crushed to obtain lithium-containing glass powder with a particle size of <150 mesh;

[0125] The lithium content in the lithium-containing glass is 1.5wt%~5.5wt%;

[0126] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0127] The calcining agent includes sodium sulfate and calcium sulfate;

[0128] The mass of the sodium sulfate is 0.7 to 1 times that of the lithium-containing glass powder;

[0129] The mass of the calcium sulfate is 0.75 to 1.5 times that of the lithium-containing glass powder;

[0130] The calcination aid includes any one or a combination of at least two of calcium oxide, calcium carbonate, or calcium fluoride.

[0131] The mass of the calcination aid is 0.02 to 0.1 times that of the lithium-containing glass powder;

[0132] The mass of water used in the wet mixing process is 8% to 12% of the mass of the mixture.

[0133] (3) The mixture is granulated and aged for 12h~48h to obtain granulated material; the granulated material is roasted at 830℃~950℃ for 1h~6h to obtain roasted clinker.

[0134] The granulation method includes roller granulation;

[0135] The granulated material obtained by granulation is an ellipsoid with a major diameter of 2.8cm to 3.2cm and a minor diameter of 1.4cm to 1.6cm.

[0136] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0137] The long diameter of the crushed roasted clinker is ≤0.5cm;

[0138] The ball milling water immersion temperature is 30℃~60℃, the time is 0.5h~4h, the liquid-solid ratio is 1:1~1:8, and the dimension of the liquid-solid ratio is mL / g;

[0139] The water-leached residue is washed with water to obtain harmless tailings. The washing temperature is 20℃~90℃, the washing time for a single wash is 0.5h~5h, the washing is repeated twice, and the liquid-to-solid ratio of the wash is 1:1mg / g~1:8mL / g.

[0140] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0141] The alkaline substance includes any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or calcium oxide;

[0142] The impurity removal process involves a pH value of 12-13, a temperature of 40℃-90℃, and a time of 1h-5h.

[0143] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0144] The carbonate includes sodium carbonate, and the amount of the carbonate used is 2 to 5 times the theoretical amount.

[0145] The calcium removal temperature is 25℃~90℃, and the time is 1h~5h;

[0146] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0147] To clearly illustrate the technical solution of the present invention, the main components of the lithium-containing glass in the following embodiments and comparative examples are shown in Table 1 below. The contents in Table 1 are mass percentages, and "others" refers to trace elements and the coordinated oxygen content of all elements:

[0148] Table 1

[0149]

[0150] Example 1

[0151] This embodiment provides a method for selectively extracting lithium from lithium-containing glass, and the process flow diagram is shown below. Figure 1 As shown, it includes the following steps:

[0152] (1) The lithium-containing glass is crushed to obtain lithium-containing glass powder with a particle size of <150 mesh;

[0153] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0154] The calcining agent is sodium sulfate and calcium sulfate;

[0155] The mass of the sodium sulfate is 0.8 times that of the lithium-containing glass powder;

[0156] The mass of the calcium sulfate is 1.1 times that of the lithium-containing glass powder;

[0157] The calcination aid is calcium oxide;

[0158] The mass of the calcination aid is 0.05 times that of the lithium-containing glass powder;

[0159] The mass of water used in the wet mixing process is 10% of the mass of the mixture.

[0160] (3) The mixture is granulated and aged for 12 hours to obtain granulated material; the granulated material is calcined at 900℃ for 2 hours to obtain calcined clinker.

[0161] The granulation method includes roller granulation;

[0162] The granulated material obtained by granulation is an ellipsoid with a major diameter of 3 cm and a minor diameter of 1.5 cm.

[0163] The sulfur-containing tail gas generated during roasting is absorbed by a sodium hydroxide solution with a concentration of 2 mol / L.

[0164] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0165] The long diameter of the crushed roasted clinker is 0.2 cm;

[0166] The ball milling water immersion temperature is 45℃, the time is 2h, the liquid-solid ratio is 1:1, and the dimension of the liquid-solid ratio is mL / g;

[0167] The water-leached residue is washed with water to obtain harmless tailings. The washing temperature is 40℃, the washing time for a single wash is 0.5h, the washing is repeated twice, and the liquid-to-solid ratio of the wash is 1:1mg / g.

[0168] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0169] The alkaline substance is sodium hydroxide;

[0170] The impurity removal process involves a pH of 12.5, a temperature of 65°C, and a time of 1 hour.

[0171] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0172] The carbonate includes sodium carbonate, and the amount of the carbonate used is three times the theoretical amount.

[0173] The calcium removal temperature is 60℃ and the time is 3 hours;

[0174] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0175] Example 2

[0176] This embodiment provides a method for selectively extracting lithium from lithium-containing glass, comprising the following steps:

[0177] (1) The lithium-containing glass is crushed to obtain lithium-containing glass powder with a particle size of <150 mesh;

[0178] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0179] The calcining agent is sodium sulfate and calcium sulfate;

[0180] The mass of the sodium sulfate is 0.7 times that of the lithium-containing glass powder;

[0181] The mass of the calcium sulfate is 0.75 times that of the lithium-containing glass powder;

[0182] The calcination aid is calcium oxide;

[0183] The mass of the calcination aid is 0.02 times that of the lithium-containing glass powder;

[0184] The mass of water used in the wet mixing process is 8% of the mass of the mixture.

[0185] (3) The mixture is granulated and aged for 30 hours to obtain granulated material; the granulated material is calcined at 830°C for 6 hours to obtain calcined clinker.

[0186] The granulation method includes roller granulation;

[0187] The granulated material obtained by granulation is an ellipsoid with a major diameter of 2.8 cm and a minor diameter of 1.4 cm.

[0188] The sulfur-containing tail gas generated during roasting is absorbed by a sodium hydroxide solution with a concentration of 2 mol / L.

[0189] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0190] The long diameter of the crushed roasted clinker is 0.5 cm;

[0191] The ball milling water immersion temperature is 30℃, the time is 4h, the liquid-solid ratio is 1:4, and the dimension of the liquid-solid ratio is mL / g;

[0192] The water-leached residue is washed with water to obtain harmless tailings. The washing temperature is 20℃, the washing time is 5 hours, the washing is repeated twice, and the liquid-to-solid ratio is 1:4 mg / g.

[0193] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0194] The alkaline substance is sodium hydroxide;

[0195] The impurity removal process involves a pH value of 12, a temperature of 40°C, and a time of 5 hours.

[0196] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0197] The carbonate includes sodium carbonate, and the amount of the carbonate used is twice the theoretical amount.

[0198] The calcium removal process is carried out at a temperature of 25°C for 5 hours.

[0199] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0200] Example 3

[0201] This embodiment provides a method for selectively extracting lithium from lithium-containing glass, comprising the following steps:

[0202] (1) The lithium-containing glass is crushed to obtain lithium-containing glass powder with a particle size of <150 mesh;

[0203] (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture;

[0204] The calcining agent is sodium sulfate and calcium sulfate;

[0205] The mass of the sodium sulfate is 1 times that of the lithium-containing glass powder;

[0206] The mass of the calcium sulfate is 1.5 times that of the lithium-containing glass powder;

[0207] The calcination aid is calcium oxide;

[0208] The mass of the calcination aid is 0.1 times that of the lithium-containing glass powder;

[0209] The mass of water used in the wet mixing process is 12% of the mass of the mixture.

[0210] (3) The mixture is granulated and aged for 48 hours to obtain granulated material; the granulated material is roasted at 950°C for 1 hour to obtain roasted clinker.

[0211] The granulation method includes roller granulation;

[0212] The granulated material obtained by granulation is an ellipsoid with a major diameter of 3.2 cm and a minor diameter of 1.6 cm.

[0213] The sulfur-containing tail gas generated during roasting is absorbed by a sodium hydroxide solution with a concentration of 2 mol / L.

[0214] (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue;

[0215] The long diameter of the crushed roasted clinker is 0.5 cm;

[0216] The ball milling water immersion temperature is 60℃, the time is 0.5h, the liquid-to-solid ratio is 1:8, and the dimension of the liquid-to-solid ratio is mL / g;

[0217] The water-leached residue is washed with water to obtain harmless tailings. The washing temperature is 90℃, the washing time for a single wash is 0.5h, the washing is repeated twice, and the liquid-to-solid ratio of the wash is 1:8mg / g.

[0218] (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue;

[0219] The alkaline substance is sodium hydroxide;

[0220] The impurity removal process was performed at a pH of 13, a temperature of 90°C, and a time of 1 hour.

[0221] (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue;

[0222] The carbonate includes sodium carbonate, and the amount of the carbonate used is 5 times the theoretical amount.

[0223] The calcium removal temperature is 90℃ and the time is 1 hour;

[0224] The decalcified solution is used to prepare battery-grade lithium carbonate.

[0225] Example 4

[0226] This embodiment provides a method for selectively extracting lithium from lithium-containing glass. Except that the calcination aid is calcium carbonate, the method is the same as in Example 1.

[0227] Example 5

[0228] This embodiment provides a method for selectively extracting lithium from lithium-containing glass, which is the same as in Example 1 except that the calcination temperature is 750°C.

[0229] Example 6

[0230] This embodiment provides a method for selectively extracting lithium from lithium-containing glass, which is the same as that in Example 1 except that granulation is not performed.

[0231] Comparative Example 1

[0232] This comparative example provides a method for selectively extracting lithium from lithium-containing glass, which is the same as in Example 1 except that no calcination aid is used.

[0233] Comparative Example 2

[0234] This comparative example provides a method for selectively extracting lithium from lithium-containing glass, which is the same as in Example 1 except that sodium sulfate is not used.

[0235] Comparative Example 3

[0236] This comparative example provides a method for selectively extracting lithium from lithium-containing glass, which is the same as in Example 1 except that calcium sulfate is not used.

[0237] Performance Characterization

[0238] The lithium recovery rate of the methods provided in the above embodiments and comparative examples was measured. The lithium recovery rate refers to the ratio of the lithium content in the decalcified solution to the lithium content in the lithium-containing glass. The results are shown in Table 2.

[0239] Table 2

[0240]

[0241] As can be seen from Examples 1 to 4 in Table 2, the lithium extraction method for lithium-containing glass provided by the present invention can achieve a high recovery rate of more than 89% of lithium element within the range of reagent ratio and process parameters defined in the claims.

[0242] A comparison of Comparative Examples 2 and 3 with Example 1 shows that only the combined use of sodium sulfate and calcium sulfate as calcining agents can achieve efficient conversion and high recovery of lithium in lithium-containing glass. This is because using only calcium sulfate without adding sodium sulfate cannot provide sufficient sulfate active sites for the conversion of the lithium phase in lithium-containing glass, making it difficult to achieve selective activation and efficient leaching of lithium, resulting in a decrease in lithium recovery. Furthermore, using only sodium sulfate without adding calcium sulfate cannot regulate the reactivity of the calcination system through the calcium-based components, making it difficult to achieve directional conversion of lithium under mild conditions, and simultaneously failing to effectively inhibit the dissolution of impurity components, leading to a decrease in lithium recovery.

[0243] As can be seen from the comparison between Comparative Example 1 and Example 1, without the use of calcination aids, the reaction environment of the calcination system cannot be optimized by calcium-based aids, making it difficult to further promote the selective conversion of lithium phase. At the same time, it is not possible to effectively suppress the dissolution of impurity components such as silicon and aluminum. Not only does the lithium recovery rate decrease, but it also increases the processing difficulty and production cost of subsequent purification processes.

[0244] A comparison of Example 5 and Example 1 shows that when the calcination temperature is too low, the calcination system cannot reach the reaction activation energy required for lithium phase transformation. As a result, the lithium phase in the lithium-containing glass is difficult to be fully activated and directionally transformed, leading to a decrease in lithium leaching efficiency and final recovery rate.

[0245] A comparison of Example 6 and Example 1 shows that when granulation is not performed, the contact area between the lithium-containing glass powder and the calcining agent is insufficient, the uniformity and sufficiency of the calcination reaction are significantly reduced, and the maximum conversion and leaching of the lithium phase cannot be achieved, ultimately resulting in a decrease in the lithium recovery rate.

[0246] In summary, this invention employs a compound calcining agent of sodium sulfate and calcium sulfate, combined with calcining aids of calcium oxide and / or calcium carbonate. Through the specific combination of these agents, highly selective conversion and leaching of lithium from lithium-containing glass can be achieved under relatively mild process conditions. This technical solution ensures a high lithium recovery rate while effectively inhibiting the leaching of impurity components, thereby simplifying subsequent purification processes, reducing overall production costs, and mitigating environmental pollution. Furthermore, the lithium extraction method provided by this invention has good universality for lithium-containing glasses with different phase compositions, possessing the advantages of wide raw material adaptability and low raw material access requirements; it also enables selective water leaching recovery of lithium resources, fundamentally preventing the leaching of large amounts of aluminum and silicon impurities from lithium-containing glass. Moreover, the granulation operation in the process effectively improves the calcination reaction efficiency, and the overall process is simple and operates stably and reliably.

[0247] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for selectively extracting lithium from lithium-containing glass, characterized in that, The method includes the following steps: (1) Lithium-containing glass is crushed to obtain lithium-containing glass powder; (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture; The calcining agent includes sodium sulfate and calcium sulfate; The calcination aid includes any one or a combination of at least two of calcium oxide, calcium carbonate, or calcium fluoride. (3) The mixture is granulated and aged to obtain granulated material; the granulated material is roasted to obtain roasted cooked material; (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue; (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue; (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue; The decalcified solution is used to prepare battery-grade lithium carbonate.

2. The method according to claim 1, characterized in that, The lithium content in the lithium-containing glass described in step (1) is 1.5wt%~5.5wt%; And / or, the particle size of the lithium-containing glass powder in step (1) is <150 mesh.

3. The method according to claim 1 or 2, characterized in that, The mass of the sodium sulfate is 0.7 to 1 times that of the lithium-containing glass powder; And / or, the mass of the calcium sulfate is 0.75 to 1.5 times that of the lithium-containing glass powder; And / or, the mass of the calcination aid is 0.02 to 0.1 times that of the lithium-containing glass powder.

4. The method according to any one of claims 1 to 3, characterized in that, The mass of water used in the wet mixing process is 8% to 12% of the mass of the mixture.

5. The method according to any one of claims 1 to 4, characterized in that, The granulation method in step (3) includes roller granulation; And / or, the granulated material obtained by granulation in step (3) is an ellipsoid, the major diameter of the ellipsoid is 2.8cm~3.2cm, and the minor diameter is 1.4cm~1.6cm; And / or, the aging time in step (3) is 12h~48h.

6. The method according to any one of claims 1 to 5, characterized in that, The roasting temperature in step (3) is 830℃~950℃; And / or, the roasting time in step (3) is 1h to 6h.

7. The method according to any one of claims 1 to 6, characterized in that, The long diameter of the crushed roasted clinker in step (4) is ≤0.5cm; And / or, the temperature of the ball mill water immersion in step (4) is 30℃~60℃; And / or, the water soaking time for ball milling in step (4) is 0.5h to 4h; And / or, the liquid-to-solid ratio of the ball milling and water immersion in step (4) is 1:1 to 1:8, and the dimension of the liquid-to-solid ratio is mL / g.

8. The method according to any one of claims 1 to 7, characterized in that, The alkaline substance mentioned in step (5) includes any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or calcium oxide; And / or, the pH value for impurity removal in step (5) is 12-13; And / or, the temperature for removing impurities in step (5) is 40℃~90℃; And / or, the time for impurity removal in step (5) is 1h to 5h.

9. The method according to any one of claims 1 to 8, characterized in that, The carbonate mentioned in step (6) includes sodium carbonate; And / or, the amount of carbonate used in step (6) is 2 to 5 times the theoretical amount; And / or, the temperature for calcium removal in step (6) is 25°C to 90°C; And / or, the calcium removal time in step (6) is 1h to 5h.

10. The method according to claim 1, characterized in that, The method includes the following steps: (1) The lithium-containing glass is crushed to obtain lithium-containing glass powder with a particle size of <150 mesh; The lithium content in the lithium-containing glass is 1.5wt%~5.5wt%; (2) Wet-mix the calcining agent, calcining aid and the lithium-containing glass powder to obtain a mixture; The calcining agent includes sodium sulfate and calcium sulfate; The mass of the sodium sulfate is 0.7 to 1 times that of the lithium-containing glass powder; The mass of the calcium sulfate is 0.75 to 1.5 times that of the lithium-containing glass powder; The calcination aid includes any one or a combination of at least two of calcium oxide, calcium carbonate, or calcium fluoride. The mass of the calcination aid is 0.02 to 0.1 times that of the lithium-containing glass powder; The mass of water used in the wet mixing process is 8% to 12% of the mass of the mixture. (3) The mixture is granulated and aged for 12h~48h to obtain granulated material; the granulated material is roasted at 830℃~950℃ for 1h~6h to obtain roasted clinker. The granulation method includes roller granulation; The granulated material obtained by granulation is an ellipsoid with a major diameter of 2.8cm to 3.2cm and a minor diameter of 1.4cm to 1.6cm. (4) The roasted clinker is crushed and then ball-milled and water-leached to separate the solid and liquid and obtain water-leached liquid and water-leached residue; The long diameter of the crushed roasted clinker is ≤0.5cm; The ball milling water immersion temperature is 30℃~60℃, the time is 0.5h~4h, the liquid-solid ratio is 1:1~1:8, and the dimension of the liquid-solid ratio is mL / g; (5) An alkaline substance is added to the water immersion solution to remove impurities, and the solid and liquid are separated to obtain the purified liquid and the purified residue; The alkaline substance includes any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or calcium oxide; The impurity removal process involves a pH value of 12-13, a temperature of 40℃-90℃, and a time of 1h-5h. (6) Carbonate is added to the purified liquid to remove calcium, and solid-liquid separation is performed to obtain the purified liquid and the calcium-removed residue; The carbonate includes sodium carbonate, and the amount of the carbonate used is 2 to 5 times the theoretical amount. The calcium removal temperature is 25℃~90℃, and the time is 1h~5h; The decalcified solution is used to prepare battery-grade lithium carbonate.

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