Pelletizing method of lithium ore concentrate

Abstract

The invention discloses a granulation method of lithium ore concentrate, which comprises the following steps: mixing the lithium ore concentrate, a roasting additive and a volatile binder, finely grinding until the particle size is more than 200 meshes, mixing with water, and granulating to obtain lithium ore concentrate particles. According to the method, due to the use of the volatile binder, the bonding strength of materials can be improved, the contact area between the lepidolite concentrate and the roasting additive can be increased, the forming and subsequent roasting effects are facilitated, the consumption of natural gas for roasting is reduced, and meanwhile, porous channels are formed due to gasification in the roasting process; the subsequent leaching rate and leaching effect can be improved, the yield of tailings can be reduced, the bonding strength between the materials can be further improved through fine grinding, the pelletizing rate can be improved, the prepared lithium ore concentrate particles are good in roasting effect when being used as a lithium extraction raw material for lithium extraction, the roasted product can be directly subjected to water leaching, the water leaching efficiency is high, the lithium leaching rate is high, and the method is suitable for industrial production. Meanwhile, the method is more environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium extraction and relates to a granulation method for lithium ore concentrate. Background Art

[0002] With the rapid development of power batteries and energy storage devices in the field of new energy, the demand for lithium carbonate as an important raw material is increasing. Among them, extracting lithium from lithium ore is an important way to obtain lithium carbonate in industry. In the process of extracting lithium from lithium ore, in order to improve the extraction rate of lithium, it is usually necessary to roast the lithium ore to change the crystal form of lithium or replace lithium from the lithium ore and form a soluble lithium salt. For example, when using sulfuric acid method, limestone method, and sulfate method to extract lithium from lithium ore, it is necessary to roast the lithium ore first. In industrial applications, rotary kilns and tunnel kilns are usually used to roast lithium ore. Among them, rotary kilns have more advantages in terms of process, production capacity, investment, land occupation, energy consumption, waste heat utilization, environmental protection, etc., and therefore have more application prospects. In addition, in order to achieve complete transformation or replacement of lithium ore, a very high roasting temperature of 900℃~1200℃ is usually required, which not only causes high energy consumption and large carbon emissions, but also high temperature rotary kiln roasting will lead to the problem of melting and ring formation of the charge, which is not conducive to normal production. In particular, when lithium ore bulk is directly fed into the furnace for roasting, the ring formation phenomenon of the rotary kiln will be more serious, and it is easy to overburn or underburn due to uneven heating, which is not conducive to improving the lithium extraction rate, and it is easy to consume a large amount of natural gas, resulting in excessively high costs. At the same time, it is also easy to generate a large amount of dust, resulting in a high dust content in the flue gas and a large flue gas treatment load.

[0003] In response to the above-mentioned technical defects, researchers have proposed a method for granulating bulk lithium ore. Before roasting, the lithium ore is first granulated with roasting additives, auxiliary agents and water. Specifically, the lithium ore is mixed with roasting additives, auxiliary agents and water, and granulated by a granulator to obtain lithium ore particles as roasting raw materials. However, the granulation methods disclosed in the prior art still have the following defects: (1) For lepidolite with a flaky structure and spodumene with a layered structure, the structure of the lithium ore itself causes poor adhesion and easy delamination, resulting in poor granulation effect, low ball formation rate or low particle strength. If the lithium ore is not ground, even if the lithium ore is mixed with a binder, the granulation effect is not very ideal and it is difficult to apply it industrially; (2) The selection of the binder is very critical. In the existing granulation methods, the binders used are all high-melting-point inorganic substances (clay, clay, silica powder or water glass and barium sulfate, ferrous sulfate, magnesium sulfate). Although they have a certain bonding effect, they are easy to increase the total amount of materials and increase the melting point of the materials, increase the energy consumption of subsequent roasting, and lead to a significant increase in production costs. In addition, the high-melting-point inorganic substances will increase the density of the particles during the roasting process, increase the difficulty of lithium leaching, or require additional crushing treatment, and require additional acid addition and pressure treatment during the leaching process, which increases the difficulty of production. In addition, the use of these additives will also increase the output of wastewater and waste residues, and easily cause secondary pollution.

[0004] Therefore, how to obtain lithium ore concentrate particles with high ball formation rate, high particle strength, and large contact area between lithium ore and roasting raw materials is of great significance for improving roasting reaction effect, reducing roasting energy consumption, and improving lithium leaching efficiency and leaching effect. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for pelletizing lithium ore concentrate with high ball forming rate, high particle strength and large contact area between lithium ore and roasting raw materials.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0007] A method for granulating lithium ore concentrate comprises the following steps:

[0008] S1, mixing lithium ore concentrate, roasting additive and volatile binder to obtain mixture B;

[0009] S2, finely grinding the mixture B until the particle size is above 200 meshes to obtain the mixture C;

[0010] S3, mixing mixed material C with water to obtain mixed material D;

[0011] S4, granulating the mixed material D to obtain lithium ore concentrate particles.

[0012] The above granulation method is further improved, in step S1, the preparation method of the mixture B comprises the following steps:

[0013] S1-1, mixing lithium ore concentrate and roasting additives to obtain a mixture A;

[0014] S1-2, mixing mixed material A with a volatile binder to obtain mixed material B.

[0015] The above-mentioned granulation method is further improved, in step S1-1, the mass ratio of the lithium ore concentrate to the roasting additive is 1:0.1-0.8; the roasting additive is at least one of calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate or a mixture thereof; the lithium ore concentrate is at least one of spodumene concentrate, lepidolite concentrate and lithium clay concentrate; the mass percentage of lithium in the lithium ore concentrate is ≥1.5%.

[0016] The above granulation method is further improved, in step S1-1, the mass ratio of the lithium ore concentrate to the roasting additive is 1:0.3-0.7.

[0017] The above-mentioned granulation method is further improved, in step S1-2, the amount of the volatile binder added is 0.1% to 20% of the total mass of the mixture A; the volatile binder is at least one of lignite and petroleum coke.

[0018] The above granulation method is further improved, in step S1-2, the amount of the volatile binder added is 1% to 10% of the total mass of the mixture A.

[0019] The above granulation method is further improved, in step S2, the particle size of the mixture C is above 300 meshes.

[0020] The above granulation method is further improved, in step S2, the particle size of the mixture C is 300 mesh to 1000 mesh.

[0021] The above granulation method is further improved, in step S3, the amount of water added is 5% to 20% of the total mass of the mixture C.

[0022] The above granulation method is further improved, in step S4, the particle size of the lithium ore concentrate particles is 8mm to 10mm.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] Aiming at the defects of the existing lithium ore granulation method, such as the complex process, high difficulty in operation, low granule balling rate, low granule strength, small contact area between lithium ore and roasting raw materials, the present invention creatively proposes a granulation method for lithium ore concentrate, firstly mixing the lithium ore concentrate, a roasting additive and a volatile binder, so that the lithium mica concentrate and the roasting additive are evenly mixed and fully contacted, so that the lithium mica concentrate and the volatile binder are bonded and fixed together, thereby being conducive to improving the contact area between the lithium mica concentrate and the roasting additive, and being conducive to the subsequent roasting effect (i.e., the improvement of the leaching rate), at the same time, the added volatile binder has a high calorific value, and can also be used as a heat supplementary agent, not only can the natural gas consumption of roasting be reduced, and these volatile binders can be gasified during the roasting process, thereby forming porous channels in the roasting product, which is conducive to improving the subsequent leaching rate and leaching effect, and at the same time, the output of tailings can also be reduced; Further, the mixture of lithium ore concentrate, roasting additive and volatile binder is finely ground. By finely grinding the mixture, the lithium ore can be ground from about 100 meshes to more than 200 meshes, so that the lithium ore concentrate becomes finer, and the morphology is gradually transformed into a granular state, which is not only beneficial to the subsequent granulation and molding, but also can further increase the contact area between the lithium mica concentrate and the roasting additive, promote the roasting conversion effect, and help to improve the lithium extraction rate by changing the morphology of the lithium ore concentrate. At the same time, fine grinding can also improve the bonding strength of the volatile binder to the lithium mica concentrate and the roasting additive, which is beneficial to the preparation of higher strength particles, and is beneficial to effectively prevent the particles from being broken during the roasting process, thereby effectively avoiding the problem of material melting and ringing during the roasting process. Finally, the mixture is granulated to obtain lithium ore concentrate particles with high balling rate, high particle strength, and large contact area between the lithium ore and the roasting raw material. In addition, the lithium ore concentrate particles prepared by the method of the present invention, when used as a raw material for lithium extraction, can not only significantly improve the roasting effect, but also achieve complete transformation and complete replacement of lithium ore under conditions of lower energy consumption, and the product after roasting can be directly water-leached at normal temperature and pressure conditions, with high water leaching efficiency and high lithium leaching rate. The water used for water leaching can be reused without generating secondary pollution such as wastewater. At the same time, there is no need to crush the roasted product before water leaching, and the use of acid and alkali can be avoided, which is more green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0026] Figure 1 It is a schematic diagram of the pelletizing process of lithium ore concentrate in an embodiment of the present invention.

[0027] Figure 2This is a diagram showing the lithium leaching effect of the roasted product in Example 1 of the present invention in the first three cycles.

[0028] Figure 3 This is a diagram showing the lithium leaching effect of the roasted product in Example 2 of the present invention in the first three cycles.

[0029] Figure 4 This is a diagram showing the lithium leaching effect of the roasted product in Example 3 of the present invention in the first three cycles. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available unless otherwise specified.

[0031] Example 1

[0032] A method for granulating lithium ore concentrate, specifically preparing lithium mica concentrate particles with lithium mica concentrate raw material, the granulation process flow chart is as follows Figure 1 As shown, the following steps are included:

[0033] S1, take 100 kg of lithium mica concentrate (100 mesh, lithium mass percentage is 2%), according to the mass ratio of lithium ore concentrate to roasting additive is 1:0.6, add roasting additive, wherein the roasting additive is a mixture of calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate, and the mass ratio of lithium mica concentrate to calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate is 1:0.3:0.1:0.1:0.1, stir, make the lithium mica concentrate and roasting additive mix evenly, fully contact, to obtain mixed material A. In the present invention, the type of roasting additive and the dosage ratio of different types of roasting additives are adjusted according to actual conditions.

[0034] S2, according to the amount of volatile binder added being 3% of the total mass of mixture A, mixture A is mixed with volatile binder (blue charcoal), and under the action of blue charcoal, the lithium mica concentrate and the roasting additive are bonded together to obtain mixture B. In the present invention, the lithium ore concentrate is first mixed with the roasting additive, and then the volatile binder is added, which is not only more conducive to forming a material with good mixing uniformity, but also conducive to increasing the contact area between the lithium mica concentrate and the roasting additive.

[0035] S3. Add the mixed material B into a ball mill and grind the mixed material B until the particle size reaches 300 meshes to obtain a mixed material C.

[0036] S4. Mix the mixture C with water in an amount of 8% of the total mass of the mixture C to obtain a mixture D.

[0037] S5. The mixed material D is granulated by a disc granulator to obtain lithium mica concentrate particles with a particle size of 10 mm.

[0038] The ball formation rate, particle strength, and subsequent roasting effect and leaching effect of the lithium mica concentrate particles prepared in Example 1 were tested, and the results are shown in Table 1.

[0039] Example 2

[0040] A method for granulating lithium ore concentrate, specifically preparing lithium mica concentrate particles with lithium mica concentrate raw material, the granulation process flow chart is as follows Figure 1 As shown, the following steps are included:

[0041] S1, take 200 kg of lithium mica concentrate (100 mesh, lithium mass percentage is 1.8%), according to the mass ratio of lithium ore concentrate to roasting additive is 1:0.7, add roasting additive, wherein the roasting additive is a mixture of calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate, and the mass ratio of lithium mica concentrate to calcium sulfate, calcium carbonate, sodium sulfate, potassium sulfate is 1:0.3:0.1:0.2:0.1, stir, make the lithium mica concentrate and roasting additive mix evenly, fully contact, to obtain mixture A.

[0042] S2. Mixture A is mixed with a volatile binder (blue charcoal) in an amount of 4% of the total mass of mixture A, and the lepidolite concentrate and the roasting additive are bonded together under the action of the blue charcoal to obtain mixture B.

[0043] S3. Add the mixed material B into a ball mill and grind the mixed material B until the particle size reaches 400 meshes to obtain a mixed material C.

[0044] S4. Mix the mixture C with water in an amount of 10% of the total mass of the mixture C to obtain a mixture D.

[0045] S5. The mixed material D is granulated by a disc granulator to obtain lithium mica concentrate particles with a particle size of 9 mm.

[0046] The ball formation rate, particle strength, and subsequent roasting and leaching effects of the lithium mica concentrate particles prepared in Example 2 were tested, and the results are shown in Table 1.

[0047] Example 3

[0048] A method for granulating lithium ore concentrate, specifically preparing lithium mica concentrate particles with lithium mica concentrate raw material, the granulation process flow chart is as follows Figure 1 As shown, the following steps are included:

[0049] S1, take 200 kg of lithium mica concentrate (100 mesh, lithium mass percentage is 2.5%), according to the mass ratio of lithium ore concentrate to roasting additive is 1:0.5, add roasting additive, wherein the roasting additive is a mixture of calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate, and the mass ratio of lithium mica concentrate to calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate is 1:0.2:0.1:0.1:0.1, stir, make the lithium mica concentrate and roasting additive mixed evenly, fully contact, to obtain mixed material A.

[0050] S2. Mixture A is mixed with a volatile binder (blue charcoal) in an amount of 5% of the total mass of mixture A, and the lepidolite concentrate and the roasting additive are bonded together under the action of the blue charcoal to obtain mixture B.

[0051] S3. Add the mixed material B into a ball mill and grind the mixed material B until the particle size reaches 500 meshes to obtain a mixed material C.

[0052] S4. Mix the mixture C with water in an amount of 13% of the total mass of the mixture C to obtain a mixture D.

[0053] S5. The mixed material D is granulated by a disc granulator to obtain lithium mica concentrate particles with a particle size of 8 mm.

[0054] The ball formation rate, particle strength, and subsequent roasting effect and leaching effect of the lithium mica concentrate particles prepared in Example 3 were tested, and the results are shown in Table 1.

[0055] Example 4

[0056] A method for granulating lithium ore concentrate is basically the same as that of Example 3, except that the volatile binder used in step S2 is petroleum coke.

[0057] The ball formation rate, particle strength, and subsequent roasting and leaching effects of the lithium mica concentrate particles prepared in Example 4 were tested, and the results are shown in Table 1.

[0058] Example 5

[0059] A method for granulating lithium ore concentrate, specifically using spodumene concentrate as a raw material to prepare spodumene concentrate particles, comprising the following steps:

[0060] S1. Take 200 kg of spodumene concentrate (100 mesh, lithium content of 6%), add the roasting additive according to the mass ratio of lithium ore concentrate to roasting additive of 1:0.5, wherein the roasting additive is a mixture of calcium carbonate, sodium sulfate and potassium sulfate, and the mass ratio of spodumene concentrate to calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate is 1:0.2:0.1:0.1:0.1, stir to make the spodumene concentrate and the roasting additive mixed evenly and fully contact to obtain mixed material A.

[0061] S2. Mixture A is mixed with a volatile binder (lignite) according to the amount of volatile binder added being 4% of the total mass of mixture A. Under the action of lignite, the spodumene concentrate and the roasting additive are bonded together to obtain mixture B, wherein the lignite in mixture B is.

[0062] S3. Add the mixed material B into a ball mill and grind the mixed material B until the particle size reaches 400 meshes to obtain a mixed material C.

[0063] S4. Mix the mixture C with water in an amount of 10% of the total mass of the mixture C to obtain a mixture D.

[0064] S5. The mixed material D is granulated by a disc granulator to obtain spodumene concentrate particles with a particle size of 8 mm.

[0065] The ball formation rate, particle strength, and subsequent roasting and leaching effects of the spodumene concentrate particles prepared in Example 5 were tested, and the results are shown in Table 1.

[0066] Comparative Example 1

[0067] A method for granulating a lithium ore concentrate is substantially the same as that of Example 3, except that no volatile binder is added in step S2, and no fine grinding is performed in step S3.

[0068] The ball formation rate, particle strength, and subsequent roasting effect and leaching effect of the lithium mica concentrate particles prepared in Comparative Example 1 were tested, and the results are shown in Table 1.

[0069] Comparative Example 2

[0070] A method for granulating lithium ore concentrate is basically the same as Example 3, except that in step S2, the binder used is clay, which does not have a high calorific value function, and no fine grinding is performed in step S3.

[0071] The ball formation rate, particle strength, and subsequent roasting effect and leaching effect of the lithium mica concentrate particles prepared in Comparative Example 2 were tested, and the results are shown in Table 1.

[0072] Comparative Example 3

[0073] A method for granulating lithium ore concentrate is basically the same as that of Example 3, except that in step S2, barium sulfate (roasting aid) is used instead of volatile binder, and fine grinding is not performed in step S3.

[0074] The ball formation rate, particle strength, and subsequent roasting effect and leaching effect of the lithium mica concentrate particles prepared in Comparative Example 3 were tested, and the results are shown in Table 1.

[0075] In Table 1-3, the calcination test of the particles is carried out in a rotary kiln, and the specific process conditions are: the calcination temperature is 900°C and the time is 45 minutes. At the same time, the calcined product is used as the raw material for water leaching, and the calcined product does not need to be crushed, and is directly leached at room temperature. The process conditions of water leaching are: the calcined product is leached by countercurrent leaching, specifically, the calcined product is sequentially soaked with the leachate obtained in different leaching stages, and the leaching is completed under the condition of keeping the liquid-solid ratio at 0.8:1, wherein the single leaching time is one day, and the total leaching is 4 days. Finally, the residual content of lithium in the calcined product after leaching treatment is determined, and the lithium leaching rate of water leaching is calculated based on the initial content of lithium in the lithium ore concentrate.

[0076] Table 1 Comparison of properties of particles prepared in Examples 1-5 and Comparative Examples 1-3

[0077]

[0078]

[0079] It can be seen from Table 1 that, compared with the conventional granulation method, the lithium ore concentrate particles prepared by the granulation method of the present invention have a higher ball formation rate, higher particle strength, and a larger contact area between the lithium ore and the roasting raw material. When it is roasted as a lithium extraction raw material, it can not only significantly improve the roasting effect, but also achieve complete transformation and complete replacement of lithium ore under lower energy consumption conditions. Moreover, the roasted product can be directly water-leached at normal temperature and pressure, with higher water leaching efficiency and higher lithium leaching rate.

[0080] In addition, in Examples 1-3, the leaching concentration of lithium in the first three cycles of the leaching process was also investigated. Figure 2-4 As shown. Figure 2-4It can be seen that in the first cycle, the leaching solution C with high lithium concentration was used to leach the roasted product. The results showed that after immersion in water for 1 hour, the lithium leaching rate was only about 50%. After immersion for 8 hours, the concentration in the leaching solution reached equilibrium, but the lithium leaching rate was still lower than 75%; in the second cycle, the leaching solution B with a lower lithium concentration than the leaching solution C was used to continue leaching the roasted product. The results showed that the lithium leaching rate was further improved to 88%; in the third cycle, the leaching solution A with a lower lithium concentration than the leaching solution B was used to continue leaching the roasted product. The results showed that the lithium leaching rate was further improved to 91%. In addition, in the fourth cycle, the leaching of the roasted product with room temperature water showed that the lithium leaching rate was further improved to 95%.

[0081] Example 6

[0082] The effect of different amounts of volatile binder added on the granulation effect was investigated. The granulation method was basically the same as that of Example 3, except that the amount of volatile binder added was different, as shown in Table 2.

[0083] The ball formation rate, particle strength, and subsequent roasting and leaching effects of the lithium mica concentrate particles prepared in Example 6 were tested, and the results are shown in Table 2.

[0084] Table 2 Comparison of properties of particles prepared under different volatile binder addition conditions in Example 6

[0085]

[0086]

[0087] As shown in Table 2, in the granulation method of the present invention, by optimizing the amount of volatile binder added to 1% to 20% of the total mass of the mixture A, the benefits are: 1. The bonding property of the lithium ore mixture is greatly improved, the ball formation rate is 100%, and the particle strength is increased (the number of times it falls from 2 meters above the ground without breaking is 30 times); 2. The volatile binder has a high calorific value, which increases the heat source of the system, and the binder and the mixture are roasted, with high thermal utilization, reducing natural gas consumption and reducing costs; 3. After the volatile binder is thermally decomposed and volatilized, capillaries are formed inside the particles, which is conducive to the direct water immersion of the subsequent roasted particles. In addition, in order to avoid overburning, the amount of volatile binder added can be further preferably 1% to 10% of the total mass of the mixture A.

[0088] Example 7

[0089] The effect of mixtures of different particle sizes on the granulation effect was investigated. The granulation method was basically the same as that of Example 3, except that the particle size of mixture C was different, as shown in Table 3.

[0090] The ball formation rate, particle strength, and subsequent roasting and leaching effects of the lithium mica concentrate particles prepared in Example 7 were tested, and the results are shown in Table 3.

[0091] Table 3 Comparison of the performance of particles prepared from mixtures of different particle sizes in Example 7

[0092]

[0093]

[0094] As can be seen from Table 3, in the granulation method of the present invention, by optimizing the particle size of the mixture C to be above 200 mesh, especially the particle size of 300 mesh to 1000 mesh, the mixture can be ground to change the flaky and layered structure of the lithium ore, and the adhesion of the lithium ore can be significantly increased.

[0095] From the above results, it can be seen that the granulation method of the present invention can produce lithium ore concentrate particles with high ball formation rate, high particle strength and large contact area between lithium ore and roasting raw materials. When it is used as a lithium extraction raw material for lithium extraction, it can not only significantly improve the roasting effect, but also achieve complete transformation and complete replacement of lithium ore under lower energy consumption conditions. Moreover, the roasted product can be directly water-leached at normal temperature and pressure, with high water leaching efficiency and high lithium leaching rate. The water used for water leaching can be reused without generating secondary pollution such as wastewater. At the same time, there is no need to crush the roasted product before water leaching, and the use of acid and alkali can be avoided, which is more green and environmentally friendly.

[0096] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for granulating lithium ore concentrate, characterized in that: The following steps are involved: S1, mixing lithium ore concentrate, roasting additive and volatile binder to obtain mixture B; S2, finely grinding the mixture B until the particle size is above 200 meshes to obtain the mixture C; S3, mixing mixed material C with water to obtain mixed material D; S4, granulating the mixed material D to obtain lithium ore concentrate particles.

2. The granulation method according to claim 1, characterized in that In step S1, the method for preparing the mixture B comprises the following steps: S1-1, mixing lithium ore concentrate and roasting additives to obtain a mixture A; S1-2, mixing mixed material A with a volatile binder to obtain mixed material B.

3. The granulation method according to claim 2, characterized in that In step S1-1, the mass ratio of the lithium ore concentrate to the roasting additive is 1:0.1-0.8; the roasting additive is at least one of calcium sulfate, calcium carbonate, sodium sulfate and potassium sulfate or a mixture thereof; the lithium ore concentrate is at least one of spodumene concentrate, lepidolite concentrate and lithium clay concentrate; the mass percentage of lithium in the lithium ore concentrate is ≥1.5%.

4. The granulation method according to claim 3, characterized in that In step S1-1, the mass ratio of the lithium ore concentrate to the roasting additive is 1:0.3-0.

7.

5. The granulation method according to claim 2, characterized in that In step S1-2, the amount of the volatile binder added is 0.1% to 20% of the total mass of the mixture A; the volatile binder is at least one of lignite and petroleum coke.

6. The granulation method according to claim 5, characterized in that In step S1-2, the amount of the volatile binder added is 1% to 10% of the total mass of the mixture A.

7. The granulation method according to any one of claims 1 to 6, characterized in that In step S2, the particle size of the mixture C is above 300 meshes.

8. The granulation method according to claim 7, characterized in that In step S2, the particle size of the mixture C is 300 mesh to 1000 mesh.

9. The granulation method according to any one of claims 1 to 6, characterized in that In step S3, the amount of water added is 5% to 20% of the total mass of the mixture C.

10. The granulation method according to any one of claims 1 to 6, characterized in that In step S4, the particle size of the lithium ore concentrate particles is 8 mm to 10 mm.

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