Application of magnetic separation method for improving lithium ore grade

Abstract

The invention relates to the technical field of lithium ore grading, in particular to application of a magnetic separation method for improving the grade of lithium ore. The method has the beneficial effects that a new application field of the dry magnetic separation method is provided; the flotation amount is reduced, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of lithium ore beneficiation technology, specifically to a magnetic separation method for improving the grade of lithium ore. 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 and its high-purity lithium salts as strategic reserves and are conducting extensive research on their application technologies.

[0003] Lithium extraction from ore is currently the primary method. The mined ore needs to be processed into high-grade concentrate before it can enter the smelting process.

[0004] The beneficiation process for lithium ore includes heavy media separation and flotation. Heavy media separation utilizes the density differences of different components in the ore for separation. Its advantages include low beneficiation cost and no pollution.

[0005] The principle of heavy media mineral processing lies in the physical separation of components based on density differences. The density of the heavy media needs to be between that of the heavy and light components. For components with similar densities, heavy media mineral processing typically cannot directly yield a concentrate.

[0006] Traditional view holds that the density of lithium-beryllium composite ore is typically 2.7 g / cm³. 3 The density of lithium concentrate is approximately 3.0~3.2 g / cm³. 3 The density of beryllium concentrate is 2.8~3.0 g / cm³. 3 Impurities such as feldspar and quartz have a density of 2.6~2.8 g / cm³. 3 Because the three components that need to be separated have similar densities and overlap, it is impossible to directly separate them using heavy media methods to obtain a concentrate.

[0007] In existing technologies, a density of 2.5~3.2 g / cm³ is typically used. 3 Pre-separation of the raw ore using heavy media can only pre-enrich the lithium ore to a grade of less than 4.8% (m / m% as Li2O). Subsequent flotation and other operations are required to obtain qualified lithium concentrate.

[0008] How to extract lithium concentrate from high-grade primary beneficiation of lithium-beryllium composite ores at a lower cost has always been a pressing need for those skilled in the art.

[0009] Magnetic separation is a method of separating magnetic minerals such as iron ore. Since lithium is non-magnetic, it cannot be separated using magnetic separation.

[0010] During the research process, the inventors of this application discovered that pre-enriched lithium ore usually contains a small amount of iron-containing waste rock.

[0011] On the one hand, for pre-enriched spodumene, to further improve its grade and ultimately reach a high-grade concentrate, the only conventional technology available is flotation. Furthermore, because iron-containing gangue (such as pyroxene) floats easily during flotation, it readily floats alongside spodumene, resulting in poor lithium flotation performance. In addition, flotation is costly and pollutes the environment.

[0012] On the other hand, under the influence of a magnetic field, analysis of the pre-enriched lithium ore after separation revealed the following unexpected phenomenon: lithium ore was enriched in non-magnetic products, while the content in magnetic products was very low.

[0013] Furthermore, since iron-bearing gangue has a low iron content and weak magnetism, wet magnetic separation is required for iron ore beneficiation technicians. However, the applicant's research found that wet magnetic separation is not effective for pre-enriched lithium ore.

[0014] Furthermore, by adjusting the experimental parameters, the applicant discovered that only under specific parameter conditions could the magnetic separation method be used to directly increase the grade of the pre-enriched 4-5% spodumene by approximately 1%. Summary of the Invention

[0015] The technical problem to be solved by the present invention is to provide a magnetic separation method for improving the grade of lithium ore, thereby solving the problems existing in the prior art.

[0016] One of the objectives of this invention is to provide a new application for the magnetic separation method; The second objective of this invention is to further study the preferred parameters.

[0017] This invention discloses a magnetic separation method for improving the grade of lithium ore, wherein the magnetic separation method is dry magnetic separation.

[0018] Furthermore, the lithium ore raw material has a particle size of 0.5–6 mm.

[0019] Preferably, the grade of the lithium ore raw material is 4-5% based on the mass fraction of Li2O.

[0020] Preferably, the magnetic field strength during the magnetic separation process is 9000~11000 Oe.

[0021] Preferably, the magnetic separation method is a dry belt high-intensity magnetic separation.

[0022] More preferably, the magnetic separation method employs dry belt high-intensity magnetic separation and involves multiple magnetic separation processes.

[0023] More preferably, the magnetic separation is performed twice. This can directly yield lithium concentrate with a grade of 6% or higher, which can be directly used for smelting.

[0024] The beneficial effects of this invention are as follows: This provides new application areas for dry magnetic separation methods; This reduces the amount of flotation required and lowers costs. Detailed Implementation

[0025] 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.

[0026] A magnetic separation method for improving the grade of lithium ore is disclosed. The method is a dry magnetic drum separator, and the lithium ore raw material has a particle size of 0.5–6 mm. The separation is performed according to the following parameters: Table 1 Raw Material and Screening Parameters

[0027] After screening, magnetic and non-magnetic products were obtained, and their test results are shown in Table 2 below: Table 2 Grade of Magnetic Separation Experiment Products

[0028] The results above show that the lithium ore grade is significantly improved and the recovery rate is high in the non-magnetic products obtained by magnetic separation.

[0029] A magnetic separation method for improving the grade of lithium ore is disclosed. The magnetic separation method is a dry belt high-intensity magnetic separation, and the lithium ore raw material has a particle size of 0.5–6 mm. The separation is performed according to the following parameters: Table 3 Raw Material and Screening Parameters

[0030] After the first screening, magnetic product 1 (preliminary selection) and intermediate products were obtained. The intermediate products underwent a second screening to obtain magnetic product 2 (selected) and non-magnetic products. The test results are shown in Table 4 below: Table 4 Grade of Magnetic Separation Experiment Products

[0031] The results above show that the lithium ore grade is significantly improved and the recovery rate is high in the non-magnetic products obtained after secondary magnetic separation.

[0032] According to the general understanding in the field of iron ore magnetic separation, wet magnetic separation is more effective than dry magnetic separation, and fine-particle magnetic separation is more effective than coarse-particle magnetic separation. However, the unexpected discovery in this application is that in the process of lithium ore magnetic separation, the opposite parameters are required.

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

[0034] Compared with the examples, Comparative Examples 1-6 used a wet magnetic separation method. Comparative Examples 1-4 used fine-particle separation, while Comparative Examples 5-6 used coarse-particle separation. Specific parameters are as follows: Table 5 Raw Material and Screening Parameters

[0035] After screening, magnetic and non-magnetic products were obtained, and their test results are shown in Table 6 below: Table 6 Grade of Magnetic Separation Experiment Products

[0036] As can be seen from the above comparative examples, wet magnetic separation cannot significantly improve the lithium grade, regardless of whether the raw material is coarse or fine.

[0037] The above test data shows that: As can be seen from Comparative Examples 1 to 4, fine-particle wet separation cannot directly obtain concentrate using magnetic separation; As can be seen from Comparative Examples 5 and 6, even with the same particle size, wet separation cannot directly obtain concentrate using magnetic separation. 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. An application of a magnetic separation method for improving the grade of lithium ore, characterized in that, The magnetic separation method is dry magnetic separation.

2. The application of the magnetic separation method according to claim 1 for improving the grade of lithium ore, characterized in that, The particle size of lithium ore raw material is 0.5–6 mm.

3. The application of the magnetic separation method according to claim 1 for improving the grade of lithium ore, characterized in that, The grade of the lithium ore raw material is 4-5% based on the mass fraction of Li2O.

4. The application of the magnetic separation method according to claim 1 for improving the grade of lithium ore, characterized in that, The magnetic field strength during magnetic separation is 9000~11000 Oe.

5. The application of the magnetic separation method according to claim 1 for improving the grade of lithium ore, characterized in that, The magnetic separation method adopted is dry belt high-intensity magnetic separation.

6. The application of the magnetic separation method according to claim 5 for improving the grade of lithium ore, characterized in that, After multiple magnetic separations.

7. The application of the magnetic separation method according to claim 6 for improving the grade of lithium ore, characterized in that, The magnetic separation is performed twice.

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