Preparation method of low-grade fine powder spodumene adhesive

Abstract

The invention discloses a preparation method of a low-grade fine powder spodumene adhesive, and belongs to the technical field of spodumene extraction. Calcium titanate, ammonium sulfate and sodium chloride are used for preparing a roasting auxiliary agent, the roasting auxiliary agent is mixed with blast furnace slag, sodium silicate and water to prepare an adhesive, the adhesive is mixed with fine powder spodumene, and then granulation is performed to prepare granular spodumene. The fine powder spodumene is granulated into granular spodumene, so that the problem that the fine powder spodumene is easy to block in production is solved; by adding the roasting aid into the adhesive, the phase transition temperature of the spodumene is reduced, and 98.2% of crystal form conversion rate can still be obtained during roasting at the temperature of 800 DEG C, so that energy conservation and consumption reduction are realized, and huge economic benefits are brought.

Description

Technical Field

[0001] This invention relates to the field of spodumene extraction technology, specifically to a method for preparing a low-grade fine-powder spodumene binder. Background Technology

[0002] Spodumene is a pyroxene mineral with the chemical formula LiAlSi₂O₆, a silicate. It is one of the main lithium-containing minerals, also containing trace amounts of calcium, magnesium, and other elements. Spodumene exists in its natural state as the α-phase. The α-type spodumene has a dense structure, making it difficult for acids and alkalis to penetrate, thus preventing the formation of lithium oxides (Li₂O₃). + Effective replacement of spodumene with α-phase results in a severely insufficient lithium extraction rate. At high temperatures, the crystal structure of spodumene transforms from the α-phase to the relatively "loose" β-phase. The β-phase of spodumene is less resistant to acid and alkali corrosion than the α-phase, making lithium extraction easier. The high-temperature transformation roasting of the α→β phase has become a key step in the mainstream lithium extraction method for spodumene in industry.

[0003] Spodumene exists in two forms depending on the beneficiation process: granular spodumene and fine-powder spodumene. Fine-powder spodumene (≥65% of the material passing through a 200-mesh sieve) constitutes the vast majority of total spodumene, making it the primary method for extracting lithium salts. However, due to its high water content and small particle size, fine-powder spodumene is prone to feed blockage in actual production, leading to waste and impacting lithium salt yield. Converting spodumene from fine powder to granular form helps address this issue. Therefore, developing innovative binders to obtain granular spodumene is a crucial step in improving spodumene lithium extraction technology. Summary of the Invention

[0004] In view of the above-mentioned prior art, the purpose of this invention is to provide a method for preparing low-grade fine spodumene binder.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a roasting aid composition for lithium extraction from spodumene, comprising calcium titanate, ammonium sulfate and sodium chloride, wherein the mass ratio of calcium titanate, ammonium sulfate and sodium chloride is (0.5-5) kg: (0.5-5) kg: (0.5-5) kg.

[0006] Furthermore, the mass ratio of calcium titanate, ammonium sulfate, and sodium chloride is (1-2) kg: (1-2) kg: (1-2) kg.

[0007] In a second aspect, the present invention provides a low-grade fine spodumene binder, comprising 2-6 parts of the roasting aid, 1-5 parts of blast furnace slag, 0.5-5 parts of sodium silicate, and 0.5-5 parts of water.

[0008] Furthermore, the roasting aid consists of 3-5 parts, 2-4 parts, 0.5-2 parts, sodium silicate, and 1-3 parts, water.

[0009] A third aspect of the present invention provides the application of the aforementioned low-grade fine spodumene binder in lithium extraction from spodumene.

[0010] A fourth aspect of the present invention provides a method for preparing granular spodumene, comprising the following steps: (1) Add the low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. (2) The mixture is extruded into cuboids of the same size in a roller granulator, and then crushed into blocks to obtain granular spodumene.

[0011] Furthermore, the fine spodumene powder is dried to a moisture content of 1-6%.

[0012] Furthermore, the amount of low-grade fine spodumene binder added is 10-20 kg of low-grade fine spodumene binder for every 100 kg of fine spodumene.

[0013] Furthermore, the extrusion pressure of the roller press granulator is 5-20 MPa.

[0014] Furthermore, the particle size of the spodumene is 1-5 mm.

[0015] The beneficial effects of this invention are: This invention uses calcium titanate, ammonium sulfate, and sodium chloride to prepare a roasting aid. This roasting aid is then mixed with blast furnace slag, sodium silicate, and water to obtain a binder. This binder is then mixed with fine spodumene powder and granulated to obtain granular spodumene. By granulating fine spodumene powder into granular spodumene, the problem of easy clogging during production is solved. Furthermore, by adding the roasting aid to the binder, the phase transformation temperature of spodumene is lowered. Even at a roasting temperature of 800℃, a crystal conversion rate of 98.2% can still be obtained, achieving energy saving and consumption reduction, and bringing significant economic benefits. Detailed Implementation

[0016] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0017] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0018] The test materials used in the embodiments of this invention, unless otherwise specified, are all conventional test materials in the art and can be purchased through commercial channels. The main components of the blast furnace slag used in this invention are 38 wt% calcium oxide, 33 wt% silicon oxide, and 17 wt% aluminum oxide.

[0019] Example 1 1. Preparation of low-grade fine spodumene binder The binder is prepared by mixing roasting aid, blast furnace slag, sodium silicate and water, with a mass ratio of 4 kg:3 kg:1 kg:2 kg.

[0020] The calcination aids used are calcium titanate, ammonium sulfate and sodium chloride, wherein the mass ratio of calcium titanate, ammonium sulfate and sodium chloride is 2kg:1kg:1kg.

[0021] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 15 kg of low-grade fine spodumene binder to 100 kg of fine spodumene powder.

[0022] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0023] Example 2 1. Preparation of low-grade fine spodumene binder The binder is prepared by mixing roasting aid, blast furnace slag, sodium silicate and water, with a mass ratio of 4 kg:3 kg:1 kg:2 kg.

[0024] The calcination aids used are calcium titanate, ammonium sulfate and sodium chloride, wherein the mass ratio of calcium titanate, ammonium sulfate and sodium chloride is 1kg:2kg:1kg.

[0025] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 100 kg of fine spodumene powder and 10 kg of low-grade fine spodumene binder.

[0026] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0027] Example 3 1. Preparation of low-grade fine spodumene binder The binder is prepared by mixing roasting aid, blast furnace slag, sodium silicate and water, with a mass ratio of 4 kg:3 kg:1 kg:2 kg.

[0028] The calcination aids used are calcium titanate, ammonium sulfate and sodium chloride, wherein the mass ratio of calcium titanate, ammonium sulfate and sodium chloride is 1 kg: 1 kg: 2 kg.

[0029] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 100 kg of fine spodumene powder plus 20 kg of low-grade fine spodumene binder.

[0030] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0031] Comparative Example 1 1. Preparation of low-grade fine spodumene binder The binder is prepared by mixing roasting aid, blast furnace slag, sodium silicate and water, with a mass ratio of 4 kg:3 kg:1 kg:2 kg.

[0032] The calcination aid used is calcium titanate.

[0033] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 15 kg of low-grade fine spodumene binder to 100 kg of fine spodumene powder.

[0034] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0035] Comparative Example 2 1. Preparation of low-grade fine spodumene binder The binder is prepared by mixing roasting aid, blast furnace slag, sodium silicate and water, with a mass ratio of 4 kg:3 kg:1 kg:2 kg.

[0036] The calcination aid used is ammonium sulfate.

[0037] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 15 kg of low-grade fine spodumene binder to 100 kg of fine spodumene powder.

[0038] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0039] Comparative Example 3 1. Preparation of low-grade fine spodumene binder The binder is prepared by mixing roasting aid, blast furnace slag, sodium silicate and water, with a mass ratio of 4 kg:3 kg:1 kg:2 kg.

[0040] The calcination aid used is sodium chloride.

[0041] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 15 kg of low-grade fine spodumene binder to 100 kg of fine spodumene powder.

[0042] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0043] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the low-grade fine spodumene binder prepared in Comparative Example 1 does not contain calcination aids, as detailed below: 1. Preparation of low-grade fine spodumene binder The binder is made by mixing blast furnace slag, sodium silicate and water. The mass ratio of the roasting aid, blast furnace slag, sodium silicate and water is 3kg:1kg:2kg.

[0044] 2. Preparation of particulate spodumene Includes the following steps: (1) Dry fine spodumene powder in a paddle dryer until the moisture content is below 3%; (2) Add low-grade fine spodumene binder to the dried fine spodumene powder and mix well to obtain a mixture. The amount added is 15 kg of low-grade fine spodumene binder to 100 kg of fine spodumene powder.

[0045] (3) The mixture is granulated in a roller press granulator, and the mixture is extruded into cuboids of the same size. Then it is crushed into blocks by a crusher. The extrusion pressure of the roller press granulator is 13MPa. The blocks are screened through a rolling screen to obtain spodumene particles with a particle size of 3mm.

[0046] Experimental Example 1: The granular spodumene obtained in Example 1 and Comparative Examples 1-4, as well as the raw material fine spodumene powder, were calcined at 800-1000℃ for 15 min to convert α-lithium to β-lithium. The crystal form conversion rate was then measured by atomic absorption spectrometry. The results of the crystal form conversion rate measurement are shown in Table 1. Table 1 Crystal form conversion rate (%) As can be seen from the table above, the crystal form conversion rate of Example 1 of the present invention is significantly higher than that of Comparative Examples 1-4 and fine spodumene. This indicates that adding a calcination aid composed of calcium titanate, ammonium sulfate and sodium chloride to the low-grade fine spodumene binder is beneficial to reducing the calcination temperature and improving the crystal form conversion rate of particulate spodumene at a lower temperature.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A roasting aid composition for lithium extraction from spodumene, characterized in that, It includes calcium titanate, ammonium sulfate and sodium chloride, wherein the mass ratio of calcium titanate, ammonium sulfate and sodium chloride is (0.5-5) kg : (0.5-5) kg : (0.5-5) kg.

2. The roasting aid composition for spodumene extraction according to claim 1, characterized in that, The mass ratio of calcium titanate, ammonium sulfate and sodium chloride is (1-2) kg: (1-2) kg: (1-2) kg.

3. A low-grade fine-powder spodumene binder, characterized in that, It includes 2-6 parts of the roasting aid as described in claim 1 or 2, 1-5 parts of blast furnace slag, 0.5-5 parts of sodium silicate, and 0.5-5 parts of water.

4. The low-grade fine spodumene binder according to claim 3, characterized in that, The roasting aid consists of 3-5 parts, 2-4 parts, 0.5-2 parts, sodium silicate, and 1-3 parts, water.

5. The application of the low-grade fine spodumene binder as described in claim 4 in lithium extraction from spodumene.

6. A method for preparing granular spodumene, characterized in that, Includes the following steps: (1) Add the low-grade fine spodumene binder of claim 4 to the dried fine spodumene powder and mix well to obtain a mixture. (2) The mixture is extruded into cuboids of the same size in a roller granulator, and then crushed into blocks to obtain granular spodumene.

7. The application according to claim 6, characterized in that, Fine spodumene powder is dried to a moisture content of 1-6%.

8. The application according to claim 6, characterized in that, The amount of low-grade fine spodumene binder added is 10-20 kg of low-grade fine spodumene binder for every 100 kg of fine spodumene.

9. The application according to claim 6, characterized in that, The extrusion pressure of the roller press granulator is 5-20 MPa.

10. The application according to claim 6, characterized in that, The particle size of spodumene is 1-5 mm.

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