Method for comprehensively recovering lithium, silicon and aluminum from sedimentary clay lithium ore

Abstract

The invention relates to the technical field of comprehensive utilization of sedimentary clay lithium ores, in particular to a method for comprehensively recovering lithium, silicon and aluminum from sedimentary clay lithium ores. The method comprises the following steps: crushing and sieving sedimentary clay lithium ore to obtain lithium ore powder; uniformly mixing the lithium ore powder with the causticized mud, roasting, and then cooling to obtain a roasted product; dipping the roasted product in water to obtain a lithium leaching solution and lithium extraction slag; the lithium extraction slag is subjected to ball milling, and ball-milled slag is obtained; soaking the ball-milled residues in inorganic acid to obtain filtrate 1 and filter residues 1; drying the filter residue 1 to obtain a silicic acid byproduct; adding sulfuric acid into the filtrate 1 for reaction, and then carrying out solid-liquid separation to obtain filtrate 2 and filter residues 2; drying the filter residue 2 to obtain a gypsum byproduct; and adding sodium hydroxide into the filtrate 2 to obtain aluminum hydroxide. The method is simple, low in energy consumption, environment-friendly and easy for large-scale industrial application.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive utilization of sedimentary clay lithium ore, and in particular to a method for comprehensively recovering lithium, silicon and aluminum from sedimentary clay lithium ore. Background Art

[0002] Lithium (Li), as an important clean energy metal, plays an important role in the fields of electric vehicles and energy storage systems. Natural lithium resources can generally be divided into three categories: salt lake brine type, hard rock type and clay type. At present, the most mined and utilized lithium mines in the world are salt lake brine type lithium mines and hard rock type lithium mines. Sedimentary clay lithium mines are a low-grade sedimentary lithium mine that was discovered relatively late and has not yet been developed and utilized on a large scale. However, the existing distribution pattern of lithium resources and actual demand have made this type of lithium mine highly valued.

[0003] However, sedimentary clay lithium ore has the characteristics of low lithium grade and complex composition. Most of the lithium recovery is achieved through acid leaching or additive roasting, without targeted treatment according to the properties of the mineral. There are problems such as low lithium recovery rate and dissolution of similar elements such as aluminum and magnesium. The subsequent separation and purification pressure is high, resulting in high commercial development costs. Therefore, for sedimentary clay lithium ore, an efficient, green, and multi-resource comprehensive extraction and recovery technology is urgently needed. Summary of the invention

[0004] Based on the above content, the present invention provides a method for comprehensively recovering lithium, silicon and aluminum from sedimentary clay lithium ore.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for comprehensively recovering lithium, silicon and aluminum from sedimentary clay lithium ore, comprising the following steps:

[0007] Step 1, crushing and sieving sedimentary clay lithium ore to obtain lithium ore powder; mixing the lithium ore powder with causticized mud and roasting, and then cooling to obtain a roasting product;

[0008] Step 2, immersing the roasted product in water to obtain a lithium leaching solution and lithium extraction slag;

[0009] Step 3, ball-milling the lithium-extracting slag to obtain ball-milled slag;

[0010] Step 4, immersing the ball-milled residue in an inorganic acid to obtain a filtrate 1 and a residue 1;

[0011] Step 5, drying the filter residue 1 to obtain a silicate byproduct; adding sulfuric acid to the filtrate 1 for reaction, followed by solid-liquid separation to obtain a filtrate 2 and a filter residue 2; drying the filter residue 2 to obtain a gypsum byproduct;

[0012] Step 6, adding sodium hydroxide to the filtrate 2 to obtain aluminum hydroxide;

[0013] The sedimentary clay lithium ore is a carbonate clay lithium ore, wherein the Li2O grade is lower than 0.6%.

[0014] In a preferred embodiment of the present invention, in step 1, the screening is specifically through a 200-mesh sieve; and the mass ratio of the lithium ore powder to the causticized mud is 10:(1-2).

[0015] In a preferred embodiment of the present invention, in step 1, the calcination temperature is 300-400° C. and the calcination time is 0.5-1.5 hours.

[0016] In a preferred embodiment of the present invention, in step 2, the mass ratio of the calcined product to the water is 1:(10-20); and the immersion time is 1-3 hours.

[0017] In some specific embodiments, lithium carbonate can be prepared by purifying and removing impurities from the lithium leaching solution described in step 2 and then adding sodium carbonate to achieve resource utilization of lithium.

[0018] In a preferred embodiment of the present invention, in step 3, the rotation speed of the ball mill is 200-300 rpm; and the time of the ball mill is 0.5-1 h.

[0019] In a preferred embodiment of the present invention, the ball milling medium is steel balls, and the material-ball ratio is 1:10.

[0020] In a preferred embodiment of the present invention, in step 4, the inorganic acid is a hydrochloric acid solution with a concentration of 2-4 mol / L; and the immersion time is 1-3 hours.

[0021] In a preferred embodiment of the present invention, in step 5, the sulfuric acid and the Ca in the filtrate 2 2+ The molar ratio is 1:1.

[0022] The present invention does not impose any particular limitation on the concentration of sulfuric acid, and any common concentration available from commercial sources, such as 5-15 mol / L, may be used.

[0023] The present invention does not impose any particular limitation on the drying temperature of the filter residue 1 and the filter residue 2 in step 5. A commonly used drying temperature in the art, such as 200° C., can be used to dry the filter residues to a constant weight.

[0024] In a preferred embodiment of the present invention, in step 6, the sodium hydroxide and the Al in the filtrate 2 3+ The molar ratio is 3:1.

[0025] The present invention discloses the following technical effects:

[0026] The present invention provides a method for comprehensive recovery of lithium, silicon and aluminum from carbonate clay-type lithium ore in sedimentary clay lithium ore. Carbonate clay-type lithium ore contains silicon-aluminum clay minerals, namely montmorillonite minerals, which have a layered structure composed of silicon-oxygen tetrahedrons and aluminum-oxygen octahedrons. Lithium mainly exists in the interlayer, which belongs to a special adsorption state. The present invention removes the hydroxyl groups of the carbonate clay-type lithium ore without destroying the structure of the montmorillonite mineral by mixing the carbonate clay-type lithium ore with causticized mud and roasting it at a lower temperature for a shorter time, thereby promoting the migration of lithium from the interlayer structure and improving the extraction rate of lithium. Ball milling the lithium extraction slag can cause the layered structure in the carbonate clay-type lithium ore to break and peel off, promote the dissolution of aluminum in subsequent inorganic acids, and improve the extraction rate of aluminum. The filter residue after aluminum extraction is dried to obtain a silicate byproduct. The method of the present invention realizes the comprehensive recovery and utilization of lithium, silicon and aluminum in low-grade sedimentary clay lithium ore, and has important practical application value.

[0027] The method of the invention is simple, low in energy consumption, environmentally friendly and easy to be applied in large-scale industrialization. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] The embodiment of the present invention provides a method for comprehensively recovering lithium, silicon and aluminum from sedimentary clay lithium ore, comprising the following steps:

[0034] Step 1, crushing sedimentary clay lithium ore (Li2O grade 0.48%) and passing through a 200-mesh sieve to obtain lithium ore powder; mixing the lithium ore powder and causticized mud in a mass ratio of 10:(1-2) and calcining at 300-400°C for 0.5-1.5 hours, then cooling to obtain a calcined product;

[0035] Step 2, immersing the roasted product in water for 1-3 hours to obtain a lithium leaching solution and lithium extraction slag; the mass ratio of the roasted product to the water is 1:(10-20);

[0036] Step 3, ball milling the lithium extraction slag, the ball milling speed is 200-300rpm, the time is 0.5-1h, the ball milling medium is steel balls, and the material-to-ball ratio is 1:10; after the ball milling is completed, ball milling slag is obtained;

[0037] Step 4, immersing the ball-milled residue in a 2-4 mol / L hydrochloric acid solution for 1-3 hours to obtain a filtrate 1 and a residue 1;

[0038] Step 5, drying the filter residue 1 to obtain a silicic acid byproduct; adding sulfuric acid to the filtrate 1 for reaction (the sulfuric acid reacts with the Ca in the filtrate 2 to obtain a silicic acid byproduct); 2+ The molar ratio of the filtrate to the filtrate is 1:1), followed by solid-liquid separation to obtain a filtrate 2 and a filter residue 2; the filter residue 2 is dried to obtain a gypsum by-product;

[0039] Step 6, adding sodium hydroxide to the filtrate 2 to react with the Al in the filtrate 2. 3+ The molar ratio is 3:1, and aluminum hydroxide is obtained after the reaction is completed.

[0040] The reaction temperature in step 6 is room temperature, and the reaction time is 1-3 hours.

[0041] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0042] The low-grade sedimentary lithium ore used in the embodiment of the present invention comes from southwest China, with a Li2O grade of 0.48%, and contains silica-alumina clay minerals, namely montmorillonite minerals, and lithium mainly exists between the montmorillonite mineral layers.

[0043] The causticized mud used in the embodiments of the present invention is a byproduct produced in the causticizing stage during the alkali recovery process of Xining Chengbeiqing Paper Mill, and its main component is calcium carbonate.

[0044] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0045] Example 1

[0046] A method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore, comprising the following steps:

[0047] Step 1, crushing sedimentary clay lithium ore (Li2O grade 0.48%) and passing through a 200-mesh sieve to obtain lithium ore powder; mixing the lithium ore powder and causticized mud in a mass ratio of 10:1 and calcining at 400°C for 0.5 hour, then cooling to obtain a calcined product;

[0048] Step 2, immersing the roasted product in water for 2 hours to obtain a lithium leaching solution and lithium extraction slag; the mass ratio of the roasted product to water is 1:20; the leaching rate of lithium in the lithium leaching solution is 97.9%, and the leaching rates of silicon and aluminum are both less than 0.5%;

[0049] Step 3, ball milling the lithium extraction slag, the ball milling speed is 300 rpm, the time is 1 hour, the ball milling medium is steel balls, and the material-to-ball ratio is 1:10; after the ball milling is completed, ball milling slag is obtained;

[0050] Step 4, immersing the ball mill residue in a 3 mol / L hydrochloric acid solution for 2 hours to obtain a filtrate 1 and a residue 1; the leaching rate of aluminum in the filtrate 1 is 96.4%, and the leaching rate of silicon is less than 0.8%;

[0051] Step 5, drying the filter residue 1 to obtain a silicic acid byproduct; adding sulfuric acid to the filtrate 1 to react (sulfuric acid reacts with Ca in the filtrate 2 to obtain a silicic acid byproduct); 2+ The molar ratio is 1:1), followed by solid-liquid separation to obtain filtrate 2 and filter residue 2; the filter residue 2 is dried to obtain gypsum by-product;

[0052] Step 6, adding sodium hydroxide to the filtrate 2 to react with the Al in the filtrate 2. 3+ The molar ratio is 3:1, and aluminum hydroxide is obtained after the reaction is completed.

[0053] Example 2

[0054] A method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore, comprising the following steps:

[0055] Step 1, crushing sedimentary clay lithium ore (Li2O grade 0.48%) and passing through a 200-mesh sieve to obtain lithium ore powder; mixing the lithium ore powder and causticized mud in a mass ratio of 10:2 and calcining at 400°C for 1 hour, then cooling to obtain a calcined product;

[0056] Step 2, immersing the roasted product in water for 3 hours to obtain a lithium leaching solution and lithium extraction slag; the mass ratio of the roasted product to water is 1:20; the leaching rate of lithium in the lithium leaching solution is 98.6%, and the leaching rates of silicon and aluminum are both less than 0.5%;

[0057] Step 3, ball milling the lithium extraction slag, the ball milling speed is 300 rpm, the time is 1 hour, the ball milling medium is steel balls, and the material-to-ball ratio is 1:10; after the ball milling is completed, ball milling slag is obtained;

[0058] Step 4, immersing the ball mill residue in a 4 mol / L hydrochloric acid solution for 3 hours to obtain a filtrate 1 and a residue 1; the leaching rate of aluminum in the filtrate 1 is 97.1%, and the leaching rate of silicon is less than 0.7%;

[0059] Step 5, drying the filter residue 1 to obtain a silicic acid byproduct; adding sulfuric acid to the filtrate 1 to react (sulfuric acid reacts with Ca in the filtrate 2 to obtain a silicic acid byproduct); 2+ The molar ratio is 1:1), followed by solid-liquid separation to obtain filtrate 2 and filter residue 2; the filter residue 2 is dried to obtain gypsum by-product;

[0060] Step 6, adding sodium hydroxide to the filtrate 2 to react with the Al in the filtrate 2. 3+ The molar ratio is 3:1, and aluminum hydroxide is obtained after the reaction is completed.

[0061] Comparative Example 1

[0062] A method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore, comprising the following steps:

[0063] Step 1, crushing sedimentary clay lithium ore (Li2O grade 0.48%) and passing through a 200-mesh sieve to obtain lithium ore powder; mixing the lithium ore powder and calcium carbonate in a mass ratio of 10:2 and calcining at 400°C for 1 hour, then cooling to obtain a calcined product;

[0064] Step 2, immersing the roasted product in water for 3 hours to obtain a lithium leaching solution and lithium extraction slag; the mass ratio of the roasted product to water is 1:20; the leaching rate of lithium in the lithium leaching solution is 89.3%, and the leaching rates of silicon and aluminum are both less than 0.5%;

[0065] Step 3, ball milling the lithium extraction slag, the ball milling speed is 300 rpm, the time is 1 hour, the ball milling medium is steel balls, and the material-to-ball ratio is 1:10; after the ball milling is completed, ball milling slag is obtained;

[0066] Step 4, immersing the ball mill residue in a 4 mol / L hydrochloric acid solution for 3 hours to obtain a filtrate 1 and a residue 1; the leaching rate of aluminum in the filtrate 1 is 96.7%, and the leaching rate of silicon is less than 0.8%;

[0067] Step 5, drying the filter residue 1 to obtain a silicic acid byproduct; adding sulfuric acid to the filtrate 1 to react (sulfuric acid reacts with Ca in the filtrate 2 to obtain a silicic acid byproduct); 2+ The molar ratio is 1:1), followed by solid-liquid separation to obtain filtrate 2 and filter residue 2; the filter residue 2 is dried to obtain gypsum by-product;

[0068] Step 6, adding sodium hydroxide to the filtrate 2 to react with the Al in the filtrate 2. 3+ The molar ratio is 3:1, and aluminum hydroxide is obtained after the reaction is completed (that is, the only difference from Example 2 is that the causticized mud is replaced by calcium carbonate).

[0069] The present invention realizes the comprehensive recovery and utilization of lithium, silicon and aluminum in sedimentary clay lithium ore, and finally no waste residue is generated, thereby fully realizing the resource utilization of sedimentary clay lithium ore.

[0070] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore, characterized in that: The following steps are involved: Step 1, crushing and sieving sedimentary clay lithium ore to obtain lithium ore powder; mixing the lithium ore powder with causticized mud and roasting, and then cooling to obtain a roasting product; Step 2, immersing the roasted product in water to obtain a lithium leaching solution and lithium extraction slag; Step 3, ball-milling the lithium-extracting slag to obtain ball-milled slag; Step 4, immersing the ball-milled residue in an inorganic acid to obtain a filtrate 1 and a residue 1; Step 5, drying the filter residue 1 to obtain a silicate byproduct; adding sulfuric acid to the filtrate 1 for reaction, followed by solid-liquid separation to obtain a filtrate 2 and a filter residue 2; drying the filter residue 2 to obtain a gypsum byproduct; Step 6, adding sodium hydroxide to the filtrate 2 to obtain aluminum hydroxide; The sedimentary clay lithium ore is a carbonate clay lithium ore, wherein the Li2O grade is lower than 0.6%.

2. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 1, the screening is specifically through a 200-mesh sieve; the mass ratio of the lithium ore powder to the causticized mud is 10:(1-2).

3. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 1, the calcination temperature is 300-400° C. and the calcination time is 0.5-1.5 hours.

4. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 2, the mass ratio of the roasted product to the water is 1:(10-20); and the immersion time is 1-3 hours.

5. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 3, the rotation speed of the ball mill is 200-300 rpm; the time of the ball mill is 0.5-1 h.

6. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 4, the inorganic acid is a hydrochloric acid solution with a concentration of 2-4 mol / L; and the immersion time is 1-3 hours.

7. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 5, the sulfuric acid and the Ca in the filtrate 2 2+ The molar ratio is 1:

1.

8. The method for comprehensive recovery of lithium, silicon and aluminum from sedimentary clay lithium ore according to claim 1, characterized in that: In step 6, the sodium hydroxide and the Al in the filtrate 2 3+ The molar ratio is 3:1.