Method for extracting lithium from electrolytic aluminum lithium-containing material and lithium-containing glass through compounding

Abstract

The invention relates to an electrolytic aluminum lithium-containing material and lithium-containing glass composite lithium extraction method. The preparation method comprises the following steps of: mixing an electrolytic aluminum lithium-containing material and a lithium-containing glass block in proportion, crushing into particles, adding an auxiliary agent, and mixing and ball-milling until the fineness is greater than 150 meshes; the mixed material is fed into a ball press machine to be pressed into blocks, then the blocks are transferred into a roasting furnace to be subjected to ventilation calcination for 3-8 h at the temperature of 500-800 DEG C, calcination clinker is obtained through natural cooling and crushing, tail gas is absorbed through spraying, and absorption liquid is treated through lime. The clinker is stirred and leached with clear water, the leaching temperature is 50-90 DEG C, the ratio of water to materials is (1-3): 1, a lithium solution and filter residues are obtained after filtering separation, and the filter residues are sent to a cement plant to be used as cement. The lithium concentration of the filtrate is (8-10) g / L, sodium carbonate is adopted for lithium precipitation to obtain lithium carbonate, and the comprehensive yield of lithium is larger than 90%.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste material recycling and relates to a recycling technology method and application of electrolytic aluminum lithium-containing materials and lithium-containing glass. Background Art

[0002] In aluminum electrolysis production, in order to improve the properties of the electrolyte, improve current efficiency and reduce energy consumption, in addition to adding aluminum fluoride or cryolite to the electrolyte, some fluoride or chloride salts are also added to the electrolyte. One of the commonly used additives is lithium fluoride. Lithium fluoride salts are currently used in the aluminum electrolysis industry to good effect. They can effectively reduce the electrolyte initial crystallization temperature and reduce fluorine emissions, which promotes energy conservation and consumption reduction in aluminum electrolysis enterprises.

[0003] The destination of lithium fluoride in the process is mainly in overhaul slag, electrolyte and carbon blocks. The total amount of waste slag reaches 1.8 million tons / year, with a lithium content of 1%-3%. With the development of lithium batteries, metallic lithium has become a necessary product. Therefore, the extraction of valuable metallic lithium from electrolytic aluminum waste slag has great commercial value.

[0004] The present invention adopts mixed calcination of electrolytic aluminum-containing material and lithium-containing glass. Under the condition of adding a small amount of auxiliary agent, the lithium in the material is converted into soluble lithium salt by utilizing the interaction between the electrolytic aluminum-containing lithium material and the glass at high temperature; the lithium salt is leached out by water and sodium carbonate is used to precipitate lithium, and the recovery rate reaches more than 90%.

[0005] Table 1 Main chemical composition of lithium-containing materials for electrolytic aluminum (carbon slag) element(%) Li F Na <![CDATA[Al2O3]]> K CaO MgO S Fe C Ni Carbon residue 1.26 27.21 11.87 13.28 0.82 1.55 0.35 1.28 0.35 47.02 0.32 Summary of the invention

[0006] The present invention uses electrolytic aluminum lithium-containing materials and lithium-containing glass to convert lithium in the materials into soluble lithium salts under the condition of high temperature of mixed auxiliary agents; the lithium salts are leached out by water, and sodium carbonate is used to precipitate lithium to obtain lithium carbonate products.

[0007] 1. Crush the lithium-containing materials and lithium-containing glass of electrolytic aluminum into particles according to the proportion, with the particles less than 0.5cm, then add additives and mix them by ball milling, with the ball milling fineness greater than 150 mesh, and then send the mixed materials into the ball press to be pressed into blocks; 2. The block material is sent into the kiln and calcined at 500℃-800℃ for 3h-8h, and then naturally cooled and crushed to obtain calcined clinker. The tail gas is sprayed and absorbed; 3. Stir and leach the clinker with clean water at a temperature of 50°C-90°C, a water-to-material ratio of (1-3):1, and a leaching time of 0.5h-1h. After filtration and separation, lithium solution and filter residue are obtained; 4. The filter residue is sent to the cement plant as cement raw material; the filtrate lithium concentration is (8-10) g / L, and lithium carbonate is obtained by lithium precipitation using sodium carbonate.

[0008] 5. According to claim 1, the method for extracting lithium from lithium-containing materials of electrolytic aluminum and lithium-containing glass, the electrolytic aluminum-containing materials are waste aluminum electrolyte, carbon slag, aluminum ash and overhaul slag from the electrolytic aluminum plant, and the lithium content is 1%-3%; the glass sheet is mainly glass for mobile phone screens, and the lithium content is 2%-5%; the ratio of the former and the latter is 1: (0.5-1), and the powder grinding fineness is >150 mesh.

[0009] 6. According to claim 1, the method for extracting lithium from lithium-containing materials and lithium-containing glass by electrolysis, characterized in that the auxiliary agent is a mixture of one or more of sodium sulfate, calcium sulfate, potassium sulfate, sodium chloride, potassium chloride, and potassium chloride, and the amount used is 0.5-1.5 times that of the lithium-containing material. 7. The technical method for recovering lithium from lithium-containing waste cathode carbon blocks from aluminum electrolysis according to claim 1, characterized in that the sodium carbonate is industrial grade with a purity of 98%. 8. The technical method for recovering lithium from lithium-containing waste cathode carbon blocks from aluminum electrolysis according to claim 1, characterized in that the main content of lithium carbonate is greater than 98%. 9. The technical method for recovering lithium from lithium-containing waste cathode carbon blocks from aluminum electrolysis according to claim 1, characterized in that the lithium carbonate precipitation temperature is 90°C-95°C, and the endpoint synthesis pH is 9-12. The method of the present invention has the following advantages: 1. Turn waste into treasure and recycle resources; 2. Short process flow, low cost and high recovery rate; 3. Small amount of wastewater, low energy consumption, can reduce the harm of cyanide and fluoride to the environment. Figure 1 The invention discloses a process flow chart of a method for extracting lithium by combining lithium-containing materials and lithium-containing glass in electrolytic aluminum.

[0010] Example 1 Weigh 500kg of carbon slag with a lithium content of 1.5%; 500kg of lithium-containing glass flakes with a lithium content of 2.2%, mix and crush into 0.2cm particles; then weigh 600kg of sodium sulfate and 400kg of calcium sulfate, mix and grind into 150 mesh powder. Send the powder into a ball press to press it into a block material, then send it into a kiln to calcine at 750℃ for 5h, and crush it into powder after natural cooling to obtain calcined clinker. Weigh 1000kg of calcined product, add 1500kg of water and stir to leach, the leaching temperature is 85℃, and the leaching time is 1h. Filter and wash to obtain filter residue and lithium sulfate solution. After testing, the lithium content in the filter residue is less than 0.1%; the mother liquor pH is 9, and the lithium concentration is 8g / L. The filtrate is added with sodium carbonate with a lithium molar ratio of 0.6 times to precipitate lithium to obtain lithium carbonate, the mother liquor lithium content is 1.2g / L, the main content of lithium carbonate is 98.1%, and the comprehensive lithium yield is 91%.

[0011] Example 2 Weigh 600kg of overhaul slag with a lithium content of 1.25%; 400kg of lithium-containing glass flakes with a lithium content of 2.2%, mix and crush into 0.2cm particles; then weigh 500kg of sodium chloride and 500kg of calcium chloride, mix and grind into 150 mesh powder. Send the powder into a ball press to press it into a block material, then send it into a kiln to calcine at 740℃ for 4h, and crush it into powder after natural cooling to obtain calcined clinker. Weigh 1000kg of calcined product, add 1500kg of water and stir to leach, the leaching temperature is 90℃, and the leaching time is 1h. Filter and wash to obtain filter residue and lithium sulfate solution. After testing, the lithium content in the filter residue is less than 0.1%; the mother liquor pH is 8, and the lithium concentration is 9g / L. The filtrate is added with sodium carbonate with a lithium molar ratio of 0.6 times to precipitate lithium to obtain lithium carbonate, the mother liquor lithium content is 1.0g / L, the main content of lithium carbonate is 98.2%, and the comprehensive lithium yield is 92%.

[0012] Comparative Example Weigh 500kg of carbon slag with a lithium content of 1.5%, add 300kg of sodium sulfate and 200kg of calcium sulfate, and mix and ball mill. Send the powder into a ball press to press it into a block material, then send it into a kiln to calcine at 750℃ for 5h, and crush it into powder after natural cooling to obtain calcined clinker. Weigh 500kg of calcined product, add 800kg of water and stir to leach, the leaching temperature is 90℃, and the leaching time is 1h. Filter and wash to obtain filter residue and lithium sulfate solution. After testing, the lithium content in the filter residue is 0.3%; the mother liquor pH is 9, and the lithium concentration is 4g / L. The filtrate is added with sodium carbonate with a lithium molar ratio of 0.6 times to precipitate lithium to obtain lithium carbonate. The mother liquor lithium content is 1.0g / L, the main content of lithium carbonate is 95.2%, and the comprehensive lithium yield is 72%.

Claims

1. A method for extracting lithium from a lithium-containing material and a lithium-containing glass by electrolysis, characterized in that: The preparation method comprises the following steps: (1) First, the electrolytic aluminum lithium-containing material and the lithium-containing glass block are mixed in proportion and crushed into particles, with the particles less than 0.5 cm, and then the mixed material is ball-milled after adding additives, with the ball-milling fineness greater than 150 mesh, and then the mixed material is sent to a ball press to be pressed into blocks; (2) The block material is transferred into a roasting furnace and calcined at 500-800℃ for 3-8h under ventilation. It is naturally cooled and crushed to obtain calcined clinker. The tail gas is sprayed and the absorption liquid is treated with lime. (3) The clinker is leached with clean water under stirring at a leaching temperature of 50°C-90°C, a water-to-material ratio of (1-3):1, and a leaching time of 0.5h-1h. After filtration and separation, a lithium solution and a filter residue are obtained; (4) The filter residue is sent to the cement plant as cement raw material; the lithium concentration of the filtrate is (8-10) g / L, and lithium is precipitated using sodium carbonate to obtain lithium carbonate.

2. The method for extracting lithium by combining lithium-containing materials and lithium-containing glass by electrolysis of aluminum according to claim 1, characterized in that The lithium-containing materials of electrolytic aluminum are waste aluminum electrolyte, carbon slag, aluminum ash and overhaul slag from electrolytic aluminum plants, with a lithium content of 1-3%; the glass sheets are mainly glass for mobile phone screens, with a lithium content of 2%-5%; the ratio of the former and the latter is 1: (0.5-1), and the powder grinding fineness is >150 mesh.

3. The method for extracting lithium by combining lithium-containing materials and lithium-containing glass by electrolysis of aluminum according to claim 1, characterized in that The auxiliary agent is a mixture of one or more of sodium sulfate, calcium sulfate, potassium sulfate, sodium chloride, potassium chloride, and potassium chloride, and the dosage is 0.5-1.5 times that of the lithium-containing material.

4. The method for extracting lithium by combining lithium-containing materials and lithium-containing glass by electrolysis of aluminum according to claim 1, characterized in that The sodium carbonate is industrial grade with a purity of 98%.

5. The method for extracting lithium by combining lithium-containing materials and lithium-containing glass by electrolysis of aluminum according to claim 1, characterized in that The main content of lithium carbonate is >98%.

6. The method for extracting lithium from a lithium-containing material and a lithium-containing glass by electrolysis of aluminum according to claim 1, characterized in that The lithium carbonate precipitation temperature is 90℃-95℃, and the final synthesis pH is 9-12.

Images