Method for comprehensively extracting valuable metal in clay type lithium ore

Abstract

The invention provides a method for comprehensively extracting valuable metals in clay type lithium ores, and belongs to the technical field of comprehensive utilization of clay type lithium ores. The method comprises the following steps: activating clay type lithium ore to obtain an activated product; the activation mode is roasting activation and / or mechanical activation; the roasting activation temperature is 450 to 850 DEG C; the rotating speed of mechanical activation is 400-900 r / min; the activated product is subjected to acid leaching, and leaching liquid and Si-enriched slag are obtained; the acid leaching temperature is 50-150 DEG C; sequentially purifying, concentrating and pyrolyzing the leachate to obtain a pyrolysis product and flue gas; and washing the pyrolysis product with water to obtain an Al2O3 product and Li-enriched liquid, and carrying out alkali adjustment and lithium precipitation on the Li-enriched liquid to obtain a Li2CO3 product. The method is short in technological process and high in extraction efficiency, inorganic acid can be regenerated and recycled, collaborative extraction and efficient separation of valuable metal lithium / aluminum are achieved, and a new technological thought is provided for comprehensive utilization of clay type lithium ore.

Description

Technical Field

[0001] The present application relates to the technical field of comprehensive utilization of clay-type lithium ore, and in particular to a method for comprehensively extracting valuable metals from clay-type lithium ore. Background Art

[0002] As a key metal for new energy, lithium is widely used in high-energy batteries (87%), ceramic glass (4%), grease (2%), flux (1%), air treatment (1%), clinical medicine (1%), and other fields (4%), and enjoys the reputation of "energy metal of the 21st century" and "metal that drives the world forward". my country has a wide variety of lithium mineral resources, mainly salt lake brine type, accounting for nearly 80% of the total domestic lithium resources, but due to the plateau environment and high Mg / Li value, the mining situation is far less than expected. Clay-type lithium ore, as an important type of lithium resource in nature, has the characteristics of large reserves, wide distribution, and easy mining. Its exploration and development may alleviate the tense situation of imbalance between supply and demand of lithium resources in my country.

[0003] The Chinese patent with publication number CN 117926032A discloses a method for selectively extracting lithium from clay-type lithium ore. The method first adds concentrated sulfuric acid to the crushed and finely ground clay-type lithium ore for sulfuric acid aging to obtain an aging product; then, the aging product is subjected to controllable thermal decomposition to obtain a thermal decomposition product and flue gas, and the flue gas is subjected to dust collection and acid production to obtain sulfuric acid, which is returned to the sulfuric acid aging process for recycling; then, the thermal decomposition product is subjected to water leaching to obtain a water leaching liquid and a water leaching residue, and the water leaching residue can be used as a raw material for aluminum extraction; finally, Na2CO3 is added to the water leaching liquid to precipitate lithium to obtain a Li2CO3 product. However, in this method, aluminum and silicon are both enriched in the water leaching residue, and the separation of aluminum and silicon is not achieved. This method only focuses on the extraction of lithium, and does not achieve the recycling of aluminum.

[0004] The Chinese patent with publication number CN 118792523A discloses a method for stepwise extraction of lithium and aluminum from clay-type lithium ore, wherein the clay-type lithium ore is subjected to roasting activation or mechanical activation or a combination of the two to obtain an activated material; the activated material is subjected to ion exchange leaching to obtain a lithium-containing solution and an aluminum-rich product; the lithium-containing solution is purified / concentrated / precipitated with lithium to obtain a lithium carbonate product; the aluminum-rich product is subjected to acid leaching to obtain an acid leaching solution and silicon-rich slag; the acid leaching solution is purified / concentrated / pyrolyzed to obtain an alumina product and regenerate an acid medium. Although this method extracts lithium and aluminum from clay-type lithium ore, the extraction process steps are cumbersome, and the extraction rate of lithium and aluminum is not high.

[0005] It can be seen that there is an urgent need to provide a process method that can easily extract lithium and aluminum from clay-type lithium ore and has a high lithium and aluminum recovery rate. Summary of the invention

[0006] In order to solve or partially solve the problems existing in the related art, the present application provides a method for comprehensively extracting valuable metals from clay-type lithium ore, which can easily extract lithium and aluminum from clay-type lithium ore and has a high recovery rate of lithium and aluminum.

[0007] The present application provides a method for comprehensively extracting valuable metals from clay-type lithium ore, comprising the following steps:

[0008] S1, activating the clay-type lithium ore to obtain an activated product;

[0009] The activation method is calcination activation and / or mechanical activation; the temperature of calcination activation is 450-850°C; the speed of mechanical activation is 400-900r / min;

[0010] S2, acid leaching the activated product to obtain a leachate and Si-enriched slag; the acid leaching temperature is 50-150°C;

[0011] S3, the leachate is purified, concentrated, and pyrolyzed in sequence to obtain pyrolysis products and flue gas;

[0012] S4, washing the pyrolysis product with water to obtain Al2O3 product and Li-enriched solution, and the Li-enriched solution is subjected to alkali adjustment and lithium precipitation to obtain Li2CO3 product.

[0013] Optionally, the calcination activation time in step S1 is 0.5 to 3 hours.

[0014] Optionally, in step S1, the time of mechanical activation is 2 to 10 hours, and the ball-to-material ratio is 1:1 to 10:1 g / g.

[0015] Optionally, the inorganic acid used for acid leaching in step S2 is hydrochloric acid, sulfuric acid or nitric acid.

[0016] Optionally, the concentration of acid leaching in step S2 is 150-400 g / L, the time is 0.5-3 h, and the liquid-to-solid ratio is 2:1-5:1 mL / g.

[0017] Optionally, when the acid leaching adopts a hydrochloric acid system, the pyrolysis temperature of step S3 is 400-600°C; when the acid leaching adopts a sulfuric acid system, the pyrolysis temperature of step S3 is 700-950°C; when the acid leaching adopts a nitric acid system, the pyrolysis temperature of step S3 is 300-450°C; and the pyrolysis time is 5-120 min.

[0018] Optionally, in step S4, the water washing temperature is 30 to 90° C., the washing time is 0.5 to 4 h, and the liquid-to-solid ratio is 2:1 to 10:1 mL / g.

[0019] The technical solution provided by this application may have the following beneficial effects:

[0020] 1) The clay mineral structure is destroyed during the roasting activation and / or mechanical activation process. During the acid leaching process, the valuable metal lithium / aluminum is fully dissociated into the leaching solution, while silicon is not leached and is enriched in the slag phase, thus achieving a complete separation of the valuable metal lithium / aluminum and the macro impurity silicon.

[0021] 2) The pyrolysis temperature is strictly controlled during the pyrolysis process so that the aluminum salt decomposes into aluminum oxide while the lithium salt remains stable. Subsequently, efficient separation of lithium / aluminum can be achieved through simple water washing.

[0022] 3) The flue gas generated in the pyrolysis process can be used to regenerate inorganic acid through dust collection and acid production, and then returned to the acid leaching process for recycling, thus realizing the regeneration cycle of inorganic acid.

[0023] 4) The process flow of this application is streamlined, the extraction efficiency is high, and the inorganic acid can be recycled and regenerated, which realizes the synergistic extraction and efficient separation of valuable metal lithium / aluminum, and provides a new process idea for the comprehensive utilization of clay-type lithium ore.

[0024] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0026] Figure 1 It is a schematic diagram of the process flow of the method for comprehensive extraction of valuable metals from clay-type lithium ore shown in the present application. DETAILED DESCRIPTION

[0027] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0028] The present application provides a method for comprehensively extracting valuable metals from clay-type lithium ore, comprising the following steps:

[0029] S1, activating the clay-type lithium ore to obtain an activated product;

[0030] The activation method is calcination activation and / or mechanical activation; the calcination activation temperature is 450-850°C; the mechanical activation speed is 400-900r / min; the calcination activation time is 0.5-3h; the mechanical activation time is 2-10h, and the ball-to-material ratio is 1:1-10:1g / g.

[0031] S2, acid leaching the activated product to obtain a leachate and Si-enriched slag; the acid leaching temperature is 50-150°C;

[0032] The inorganic acid used for acid leaching is hydrochloric acid, sulfuric acid or nitric acid. The concentration of acid leaching is 150-400 g / L, the time is 0.5-3 h, and the liquid-to-solid ratio is 2:1-5:1 mL / g.

[0033] S3, the leachate is purified, concentrated, and pyrolyzed in sequence to obtain pyrolysis products and flue gas;

[0034] When the acid leaching adopts the hydrochloric acid system, the pyrolysis temperature is 400-600°C; when the acid leaching adopts the sulfuric acid system, the pyrolysis temperature is 700-950°C; when the acid leaching adopts the nitric acid system, the pyrolysis temperature is 300-450°C; the pyrolysis time is 5-120 minutes.

[0035] S4, washing the pyrolysis product with water to obtain Al2O3 product and Li-enriched solution, and the Li-enriched solution is subjected to alkali adjustment and lithium precipitation to obtain Li2CO3 product.

[0036] The water washing temperature is 30-90°C, the washing time is 0.5-4h, and the liquid-to-solid ratio is 2:1-10:1mL / g.

[0037] In order to more clearly demonstrate the technical solution and technical effects provided by the present application, a method for comprehensive extraction of valuable metals from clay-type lithium ore provided by the present application is described in detail with specific embodiments below.

[0038] Example 1

[0039] S1. Activation: calcining the clay-type lithium ore at 600° C. for 2 h to obtain an activated product;

[0040] S2, acid leaching: add 150g / L hydrochloric acid to the activated product obtained in step S1 at a liquid-solid ratio of 5:1mL / g and react at 110°C for 3h. After the acid leaching is completed, a leachate and Si-enriched slag are obtained by liquid-solid separation. The Si-enriched slag can be used as a raw material for Si extraction;

[0041] S3, purification / concentration / pyrolysis: the leachate obtained in step S2 is purified and concentrated, and then pyrolyzed at 400°C for 120 min to obtain pyrolysis products and flue gas. The flue gas is subjected to dust collection and acid production to obtain hydrochloric acid, and the regenerated hydrochloric acid is returned to step S2 for recycling;

[0042] S4, water washing: Control the liquid-solid ratio to 10:1 mL / g, wash the pyrolysis product obtained in step S3 with water at 90°C for 0.5h to obtain Al2O3 product and Li-enriched solution, and obtain Li2CO3 product by adjusting the alkali and precipitating lithium from the Li-enriched solution. The comprehensive recovery rates of Li and Al in the whole process are 92% and 77% respectively.

[0043] Example 2

[0044] S1. Activation: Mechanically activate the clay-type lithium ore at a ball-to-material ratio of 5:1 g / g and a rotation speed of 400 r / min for 10 h to obtain an activated product;

[0045] S2, acid leaching: add 200g / L hydrochloric acid to the activated product obtained in step S1 at a liquid-solid ratio of 2:1mL / g and react at 50°C for 1h. After the acid leaching is completed, a leachate and Si-enriched slag are obtained by liquid-solid separation. The Si-enriched slag can be used as a raw material for Si extraction;

[0046] S3, purification / concentration / pyrolysis: the leachate obtained in step S2 is purified and concentrated, and then pyrolyzed at 600°C for 5 minutes to obtain pyrolysis products and flue gas. The flue gas is subjected to dust collection and acid production to obtain hydrochloric acid, and the regenerated hydrochloric acid is returned to step S2 for recycling;

[0047] S4, water washing: Control the liquid-solid ratio to 6:1 mL / g, wash the pyrolysis product obtained in step S3 with water at 60°C for 1.5h to obtain Al2O3 product and Li-enriched solution, and obtain Li2CO3 product by adjusting the alkali and precipitating lithium from the Li-enriched solution. The comprehensive recovery rates of Li and Al in the whole process are 88% and 80% respectively.

[0048] Example 3

[0049] S1. Activation: The clay-type lithium ore was first mechanically activated for 5 h at a ball-to-material ratio of 6:1 g / g and a rotation speed of 800 r / min, and then calcined at 450° C. for 3 h to obtain an activated product;

[0050] S2, acid leaching: add 400g / L sulfuric acid to the activated product obtained in step S1 at a liquid-solid ratio of 3:1mL / g and react at 70°C for 2h. After the acid leaching is completed, a leachate and Si-enriched slag are obtained by liquid-solid separation. The Si-enriched slag can be used as a raw material for Si extraction;

[0051] S3, purification / concentration / pyrolysis: the leachate obtained in step S2 is purified and concentrated, and then pyrolyzed at 700°C for 120 min to obtain pyrolysis products and flue gas. The flue gas is subjected to dust collection and acid production to obtain sulfuric acid, and the regenerated sulfuric acid is returned to step S2 for recycling;

[0052] S4, water washing: Control the liquid-solid ratio to 8:1 mL / g, wash the pyrolysis product obtained in step S3 with water at 30°C for 1 hour to obtain Al2O3 product and Li-enriched solution, and obtain Li2CO3 product by adjusting the alkali and precipitating lithium from the Li-enriched solution. The comprehensive recovery rates of Li and Al in the whole process are 89% and 78% respectively.

[0053] Example 4

[0054] S1. Activation: calcining the clay-type lithium ore at 700° C. for 1 h to obtain an activated product;

[0055] S2, acid leaching: add 250g / L sulfuric acid to the activated product obtained in step S1 at a liquid-solid ratio of 3:1mL / g and react at 90°C for 2.5h. After the acid leaching is completed, a leachate and Si-enriched slag are obtained by liquid-solid separation. The Si-enriched slag can be used as a raw material for Si extraction;

[0056] S3, purification / concentration / pyrolysis: the leachate obtained in step S2 is purified and concentrated, and then pyrolyzed at 950°C for 5 minutes to obtain pyrolysis products and flue gas. The flue gas is subjected to dust collection and acid production to obtain sulfuric acid, and the regenerated sulfuric acid is returned to step S2 for recycling;

[0057] S4, water washing: Control the liquid-solid ratio to 2:1 mL / g, wash the pyrolysis product obtained in step S3 with water at 50°C for 4 hours to obtain Al2O3 product and Li-enriched solution, and obtain Li2CO3 product by adjusting the alkali and precipitating lithium from the Li-enriched solution. The comprehensive recovery rates of Li and Al in the whole process are 93% and 75% respectively.

[0058] Example 5

[0059] S1. Activation: Mechanically activate the clay-type lithium ore at a ball-to-material ratio of 1:1 g / g and a rotation speed of 900 r / min for 2 h to obtain an activated product;

[0060] S2, acid leaching: add 350g / L nitric acid to the activated product obtained in step S1 at a liquid-solid ratio of 2:1mL / g and react at 130°C for 0.5h. After the acid leaching is completed, a leachate and Si-enriched slag are obtained by liquid-solid separation. The Si-enriched slag can be used as a raw material for Si extraction;

[0061] S3, purification / concentration / pyrolysis: the leachate obtained in step S2 is purified and concentrated, and then pyrolyzed at 300°C for 120 minutes to obtain pyrolysis products and flue gas. The flue gas is subjected to dust collection and acid production to obtain nitric acid, and the regenerated nitric acid is returned to step S2 for recycling;

[0062] S4, water washing: Control the liquid-solid ratio to 5:1 mL / g, wash the pyrolysis product obtained in step S3 with water at 40°C for 3 hours to obtain Al2O3 product and Li-enriched solution, and obtain Li2CO3 product by adjusting the alkali and precipitating lithium from the Li-enriched solution. The comprehensive recovery rates of Li and Al in the whole process are 90% and 79% respectively.

[0063] Example 6

[0064] S1. Activation: The clay-type lithium ore was first mechanically activated for 8 h at a ball-to-material ratio of 10:1 g / g and a rotation speed of 600 r / min, and then calcined and activated at 850° C. for 0.5 h to obtain an activated product;

[0065] S2, acid leaching: add 300g / L nitric acid to the activated product obtained in step S1 at a liquid-solid ratio of 4:1mL / g and react at 150°C for 1.5h. After the acid leaching is completed, a leachate and Si-enriched slag are obtained by liquid-solid separation. The Si-enriched slag can be used as a raw material for Si extraction;

[0066] S3, purification / concentration / pyrolysis: the leachate obtained in step S2 is purified and concentrated, and then pyrolyzed at 450°C for 5 minutes to obtain pyrolysis products and flue gas. The flue gas is subjected to dust collection and acid production to obtain nitric acid, and the regenerated nitric acid is returned to step S2 for recycling;

[0067] S4, water washing: Control the liquid-solid ratio to 4:1 mL / g, wash the pyrolysis product obtained in step S3 with water at 80°C for 2h to obtain Al2O3 product and Li-enriched solution, and obtain Li2CO3 product by adjusting the alkali and precipitating lithium from the Li-enriched solution. The comprehensive recovery rates of Li and Al in the whole process are 91% and 76% respectively.

[0068] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

[0069] Comparative Example 1

[0070] The difference between Comparative Example 1 and Example 1 is that the clay-type lithium ore is directly acid-leached without activation, and the results show that the comprehensive recovery rates of Li and Al in the whole process are 55% and 34%, respectively.

[0071] Comparative Example 2

[0072] The difference between Comparative Example 2 and Example 1 is that the calcination activation temperature is 400° C. The results show that the comprehensive recovery rates of Li and Al in the whole process are 69% and 51% respectively.

[0073] Comparative Example 3

[0074] The difference between Comparative Example 3 and Example 2 is that the mechanical activation speed is 300 r / min. The results show that the comprehensive recovery rates of Li and Al in the whole process are 62% and 45% respectively.

[0075] Comparative Example 4

[0076] The difference between Comparative Example 4 and Example 2 is that the acid leaching temperature is 40° C. The results show that the comprehensive recovery rates of Li and Al in the whole process are 66% and 47% respectively.

[0077] It can be seen from Comparative Examples 1 to 4 that direct acid leaching of clay-type lithium ore without activation, a roasting activation temperature of 400°C, a mechanical activation speed of 300r / min, and an acid leaching temperature of 40°C will lead to a decrease in the comprehensive recovery rate of Li and Al in the whole process. The present application optimizes the activation conditions of clay-type lithium ore, the acid leaching temperature, and strictly controls the pyrolysis temperature during the pyrolysis process to achieve a streamlined process flow, high extraction efficiency, and synergistic extraction and efficient separation of valuable metal lithium / aluminum with renewable and recyclable inorganic acids, providing a new process idea for the comprehensive utilization of clay-type lithium ore.

[0078] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for comprehensive extraction of valuable metals from clay-type lithium ore, characterized in that: The following steps are involved: S1, activating the clay-type lithium ore to obtain an activated product; The activation method is calcination activation and / or mechanical activation; the temperature of the calcination activation is 450-850°C; the speed of the mechanical activation is 400-900r / min; S2, acid leaching the activated product to obtain a leachate and Si-enriched slag; the acid leaching temperature is 50-150° C.; S3, the leachate is purified, concentrated, and pyrolyzed in sequence to obtain pyrolysis products and flue gas; S4, washing the pyrolysis product with water to obtain an Al2O3 product and a Li-enriched solution, and the Li-enriched solution is subjected to alkali adjustment and lithium precipitation to obtain a Li2CO3 product.

2. The method according to claim 1, characterized in that The calcination activation time in step S1 is 0.5 to 3 hours.

3. The method according to claim 1, characterized in that The mechanical activation time in step S1 is 2 to 10 hours, and the pellet-to-material ratio is 1:1 to 10:1 g / g.

4. The method according to claim 1, characterized in that: The inorganic acid used for acid leaching in step S2 is hydrochloric acid, sulfuric acid or nitric acid.

5. The method according to claim 4, characterized in that The acid leaching concentration in step S2 is 150-400 g / L, the time is 0.5-3 h, and the liquid-to-solid ratio is 2:1-5:1 mL / g.

6. The method according to claim 1, characterized in that When the acid leaching adopts a hydrochloric acid system, the pyrolysis temperature of step S3 is 400-600°C; when the acid leaching adopts a sulfuric acid system, the pyrolysis temperature of step S3 is 700-950°C; when the acid leaching adopts a nitric acid system, the pyrolysis temperature of step S3 is 300-450°C; the pyrolysis time is 5-120 minutes.

7. The method according to claim 1, characterized in that The water washing temperature in step S4 is 30-90° C., the washing time is 0.5-4 h, and the liquid-to-solid ratio is 2:1-10:1 mL / g.

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