A lithium roasting aid composition and a lithium ore roasting method

Abstract

The present application relates to the technical field of limestone lithium extraction production, in particular to a fire method lithium extraction roasting additive composition and a fire method ore lithium extraction method.The present application has the beneficial effect that the calcium carbide slag is used as an additive, the raw material price is low, the limestone addition amount is reduced, and the energy consumption is lower.

Description

Technical Field

[0001] This invention relates to the field of limestone lithium extraction technology, specifically a pyrometallurgical lithium extraction roasting aid composition and a pyrometallurgical ore lithium extraction method. Background Technology

[0002] Lithium, as a crucial rare element for promoting modernization and the development of related industries such as science and technology, is one of the most promising new energy sources and strategic resources. It is widely used in high-energy lithium batteries, the rubber industry, aerospace, ceramics, lasers, medicine, welding, explosives, cement, metallurgy, and new energy, earning it the title of "the energy metal of the 21st century." Many countries, considering both economic development needs and national security, have designated lithium products as strategic reserves and are conducting extensive research into their application technologies.

[0003] In existing technologies, lithium extraction is mainly divided into lithium extraction from ore and lithium extraction from salt lakes, depending on the raw materials. Among them, lithium extraction from ore technology mainly utilizes lithium-containing natural minerals such as spodumene and lepidolite to produce lithium carbonate through smelting.

[0004] Currently, the main technologies for lithium extraction from ore include the sulfuric acid process and the limestone process. Among them, the ore process is the mainstream technology. However, this process consumes large amounts of sulfuric acid and alkali, and produces a large amount of sodium sulfate as a byproduct. First, in regions with weak industrial bases, such as Africa, sulfuric acid is difficult to obtain conveniently; second, in some areas with high environmental protection requirements, the use of sulfuric acid is prohibited.

[0005] The limestone process, which uses readily available limestone as the main raw material, perfectly solves the application problems of the sulfuric acid process.

[0006] The limestone smelting process mainly involves raw material blending, roasting, and leaching. The blending ratio of the raw material composition has a significant impact on the yield of the final product. Therefore, obtaining an optimal blending ratio of the raw material composition is an urgent need for those skilled in the art.

[0007] The applicant discovered in previous research that calcium oxide can be added as an additive, but calcium hydroxide cannot be added during the process, and the relevant data has been published in Chinese patent application No. 202311871836.4.

[0008] The disadvantages of the aforementioned patents are: 1. The amount of limestone and calcium oxide added is relatively large, which will increase the additional cost of removing calcium ions later; 2. All raw materials must be purchased externally, and solid waste cannot be used as raw materials.

[0009] Furthermore, the aforementioned patent found that adding calcium hydroxide leads to clumping and a decrease in leaching rate.

[0010] Based on the aforementioned patents, in order to further reduce costs and achieve maximum economic value, the applicant further explored and obtained the technical solution of this application. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a method for lithium extraction from pyrometallurgical ore, which solves the problems existing in the prior art.

[0012] One of the objectives of this invention is to reduce the amount of calcium (including limestone, calcium oxide, etc.) added while ensuring lithium recovery rate; The second objective of this invention is to reduce costs by using cheaper waste materials as raw materials while ensuring lithium recovery rates. The third objective of this invention is to disclose a new pyrometallurgical method for lithium extraction.

[0013] This invention discloses a pyrometallurgical lithium extraction roasting aid composition, which, by mass fraction, comprises 1 part lithium ore, 0.7-2.5 parts calcium carbide slag, and 0.5-2 parts limestone.

[0014] Furthermore, the lithium ore is spodumene.

[0015] Preferably, after converting the calcium elements in the carbide slag and limestone together into the mass of calcium oxide, the mass fraction is calculated as m. 锂矿石 :m 氧化钙 The ratio is 1:1.38~1.98.

[0016] Furthermore, the lithium content (calculated as Li2O) in the lithium ore is 4.0–6.0% by mass fraction.

[0017] Preferably, the lithium content (calculated as Li2O) in the lithium ore is 5.54% by mass fraction.

[0018] Furthermore, the calcium hydroxide content in the solid waste carbide slag is 90% by mass fraction.

[0019] This invention also discloses a method for lithium extraction from pyrometallurgical ore, comprising the following steps: S1. Prepare the raw material composition by mixing lithium ore and solid waste calcium carbide slag according to the raw material ratio; S2. Granulation: Add water to the raw material mixture prepared in step S1, stir evenly, and then granulate; by mass fraction, m 原料混合物 :m 水 The ratio is 100:15; S3. Calcination: Calcination of the granulated product from step S2. S4. Grinding: Grind the product after calcination in step S3 to 200 mesh (-0.074 mm). S5. Leaching: The grinding product from step S4 is leached in water to obtain a lithium-containing solution. The lithium-containing solution can be processed by a conventional lithium precipitation process to obtain the lithium product.

[0020] Furthermore, in step S2, the roasting temperature is 1100℃ and the roasting time is 60min.

[0021] Furthermore, the grinding time in step S4 is 0.5~1h.

[0022] Preferably, the S5 leaching step is divided into two steps: first, a first-stage leaching is performed, and then the leached residue is subjected to a second-stage leaching.

[0023] For a more selective approach, by mass fraction, the first leaching temperature is 95℃, the liquid-to-solid ratio is 6:1, and the leaching time is 3 hours; the second leaching temperature is 120℃, the liquid-to-solid ratio is 6:1, and the leaching time is 3 hours.

[0024] Furthermore, the method for extracting lithium from pyrometallurgical ore also includes the following steps: S6. Washing: Wash the filter residue after filtering the product from step S5 by stirring and washing twice.

[0025] The beneficial effects of this invention are as follows: Compared to using a mixture of limestone, calcium oxide, and lithium ore, the raw material price is lower.

[0026] By reducing the amount of calcium ions added, energy consumption is reduced, and the cost of subsequent recycling is also lowered.

[0027] The innovative discovery revealed that the effect of using carbide slag is better than that of using pure calcium hydroxide.

[0028] Because limestone needs to absorb heat to decompose during the roasting process, but carbide slag releases heat during the roasting process, replacing limestone with carbide slag reduces the amount of limestone required, thereby reducing energy consumption.

[0029] The lithium leaching rate is higher than when using carbide slag alone; The product after roasting is relatively loose, and it can be ground to 200 mesh in a short time. Detailed Implementation

[0030] The specific embodiments of the present invention will be further described below with reference to the examples. The following examples are only used to illustrate the technical embodiments of the present invention more clearly, and should not be used to limit the scope of protection of the present invention. Example

[0031] A method for extracting lithium from pyrometallurgical ore includes the following steps: S1. Prepare the raw material composition by mixing lithium ore and solid waste calcium carbide slag according to the raw material ratio, by mass fraction, m 锂矿石 :m 电石渣 :m 石灰石 The ratio is 1:1.2:1; the lithium content (calculated as Li2O) in the lithium ore is 5.54%, and the calcium hydroxide content in the carbide slag is 90%. S2. Granulation: Add water to the raw material mixture prepared in step S1, stir evenly, and then granulate; by mass fraction, m 原料混合物 :m 水 The ratio is 100:15; S3. Calcination: The raw material mixture prepared in step S1 is calcined at a temperature of 1100℃ for 60 minutes. S4. Grinding: Grind the product calcined in step S3 for 0.5 hours until it reaches 200 mesh (-0.074 mm). S5. Leaching: The grinding product from step S4 is leached in water. By mass fraction, the first leaching temperature is 95℃, the liquid-to-solid ratio is 6:1, and the leaching time is 3h; the second leaching temperature is 120℃, the liquid-to-solid ratio is 6:1, and the leaching time is 3h. After leaching, a lithium-containing solution is obtained, and the lithium product can be obtained from the lithium-containing solution through a conventional lithium precipitation process.

[0032] The differences between Examples 2-5 and Example 1 are shown in Table 1 below: Table 1. Formulation Parameters of Examples (by Mass Fraction)

[0033] To further illustrate the beneficial effects of the technical solution of the present invention, the following comparative examples are provided:

[0034] The only difference between Comparative Examples 1-5 and Examples 1-5 is the parameters; the specific parameters are shown in Table 2 below: Table 2. Parameter table for the formulation of the examples and comparative examples (in mass fraction).

[0035] Note: When the "water addition" in the table above is 0, there is no S2 granulation step, and the raw material mixture is directly roasted.

[0036] To further verify the beneficial effects of the present invention, the above embodiments and comparative examples were leached according to the method described in step S5 of Embodiment 1, and the data are shown in Table 3 below: Table 3 Leaching Results Data Table

[0037] The above results were analyzed as follows: As can be seen from the comparison between Example 1 and Comparative Example 1, adding water for granulation can increase the leaching rate.

[0038] As can be seen from the comparison between Examples 1-4 and Comparative Examples 3-4, the embodiments of the present invention can significantly reduce grinding time and save energy.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pyrometallurgical lithium extraction roasting aid composition, characterized in that, By mass fraction, it consists of 1 part lithium ore, 0.7-2.5 parts calcium carbide slag, and 0.5-2 parts limestone.

2. The pyrometallurgical lithium extraction roasting aid composition according to claim 1, characterized in that, After converting the calcium elements in both carbide slag and limestone into the mass of calcium oxide, and expressing it as a mass fraction, m 锂矿石 :m 氧化钙 The ratio is 1:1.38~1.

98.

3. The pyrometallurgical lithium extraction roasting aid composition according to claim 1, characterized in that, The lithium content (calculated as Li2O) in lithium ore is 4.0 to 6.0% by mass fraction.

4. The pyrometallurgical lithium extraction roasting aid composition according to claim 1, characterized in that, The lithium ore is spodumene.

5. The pyrometallurgical lithium extraction roasting aid composition according to claim 1, characterized in that, The calcium hydroxide content in the solid waste carbide slag is 90% by mass fraction.

6. A method for extracting lithium from pyrometallurgical ore, characterized in that, Includes the following steps: S1. Prepare the raw material composition by mixing lithium ore and solid waste calcium carbide slag according to the raw material ratio; S2. Granulation: Add water to the raw material mixture prepared in step S1, stir evenly, and then granulate. In terms of mass fraction, m 原料混合物 :m 水 The ratio is 100:15; S3, calcination: calcination of the granulated product from step S2; S4. Grinding: Grind the product after calcination in step S3 to 200 mesh (-0.074 mm). S5. Leaching: The grinding product from step S4 is leached in water to obtain a lithium-containing solution. The lithium-containing solution can be processed by a conventional lithium precipitation process to obtain the lithium product.

7. The method for lithium extraction from pyrometallurgical ore according to claim 6, characterized in that, The grinding time in step S4 is 0.5~1h.

8. The method for lithium extraction from pyrometallurgical ore according to claim 6, characterized in that, The S5 leaching step is divided into two steps: first, a first-stage leaching is performed, and then the leached residue is subjected to a second-stage leaching.

9. The method for lithium extraction from pyrometallurgical ore according to claim 6, characterized in that, Based on mass fraction, the first stage leaching temperature is 95℃, the liquid-to-solid ratio is 6:1, and the leaching time is 3h; the second stage leaching temperature is 120℃, the liquid-to-solid ratio is 6:1, and the leaching time is 3h.

10. The method for lithium extraction from pyrometallurgical ore according to any one of claims 6 to 9, characterized in that, Includes the following steps: S6. Washing: Wash the filter residue after filtering the product from step S5 by stirring and washing twice.

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