A method for beneficiating a coarse fraction of a lithium ore
By screening lithium ore and using dry belt magnetic separation, the problems of low efficiency and high cost in the separation of lithium-beryllium composite ores in existing technologies have been solved, achieving efficient, low-cost, and environmentally friendly separation of lithium concentrate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XINJIANG RES INST OF NON FERROUS METALS
- Filing Date
- 2025-01-21
- Publication Date
- 2026-07-21
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Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium ore beneficiation technology, specifically a method for beneficiating coarse-grained 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 pre-enriched spodumene of about 5% be directly refined into lithium concentrate of about 6% using magnetic separation, which could then be directly used for smelting. Summary of the Invention
[0015] The technical problem to be solved by the present invention is to provide a method for beneficiating coarse-grained lithium ore, which solves the problems existing in the prior art.
[0016] The purpose of this invention is to provide a magnetic separation method for directly obtaining lithium concentrate.
[0017] This invention discloses a method for beneficiating coarse-grained lithium ore, comprising the following steps: S1. Screening: The lithium ore raw material with a particle size of 0.5 to 6 mm is screened into multiple intermediate products of different particle size ranges. S2. The intermediate products are introduced into the magnetic separation device respectively; high-grade lithium ore can be obtained respectively.
[0018] Furthermore, in step S1, the raw materials are sieved into 0.5–3 mm and 3–6 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 coarser-grained intermediate products are subjected to three magnetic separations, and the finer-grained intermediate products are subjected to two magnetic separations.
[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. First, screen to narrow the particle size distribution range, then use magnetic separation to improve separation efficiency; Lithium concentrate can be obtained directly. 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. Example
[0026] A method for beneficiating coarse-grained lithium ore includes the following steps: S1. Sieving: The lithium ore raw material with a particle size of 0.5–6 mm (based on the mass fraction of Li2O, the grade of the lithium ore raw material is 5.08%) is sieved into two intermediate particle sizes: 0.5–3 mm and 3–6 mm. The lithium ore parameters before and after sieving are as follows: Table 1. Ore parameters before and after screening
[0027] S2. The intermediate products 1 and 2 are respectively introduced into a dry belt high-intensity magnetic separator. Intermediate product 1 undergoes three magnetic separations, and intermediate product 2 undergoes two magnetic separations. The specific parameters are as follows: Table 2 Magnetic Separation Parameters
[0028] The following results were obtained after testing the products separated by magnetic separation: Table 3 Grade of Magnetic Separation Experiment Products
[0029] As can be seen from the above, high-grade lithium ore with a high yield can be obtained by screening followed by magnetic separation.
[0030] The only difference between Examples 2-4 and Example 1 is the roller diameter used in step S2. The specific parameters are as follows: Table 4 Magnetic Separation Parameters
[0031] The following results were obtained after testing the products separated by magnetic separation: Table 4 Grade of Magnetic Separation Experiment Products
[0032] To further illustrate the beneficial effects of the present invention, the following comparative examples are provided:
[0033] Compared with the examples, Comparative Examples 1 and 2 use a dry magnetic drum for magnetic separation without prior screening, and sort according to the following parameters: Table 5 Raw Material and Screening Parameters
[0034] 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
[0035] The results above indicate that the grade improvement effect of lithium ore obtained by the dry magnetic drum method is poor.
[0036] Compared with the examples, Comparative Examples 3-5 used a dry belt magnetic separator, but without screening, and sorted according to the following parameters: Table 7 Raw Material and Screening Parameters
[0037] 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 8 Grade of Magnetic Separation Experimental Products
[0038] The results above show that, under the premise of comparable recovery rates, screening can yield some higher-grade ores.
[0039] 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.
[0040] To further verify the above conclusions, comparative examples 6 to 11 were set up. Compared with the examples, Comparative Examples 6-11 used a wet magnetic separation method. Comparative Examples 6-9 used a fine-particle size separation, while Comparative Examples 10-11 used a coarse-particle size separation. Specific parameters are as follows: Table 5 Raw Material and Screening Parameters
[0041] 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
[0042] 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.
[0043] 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 method for beneficiating coarse-grained lithium ore, characterized in that, Includes the following steps: S1. Screening: The lithium ore raw material with a particle size of 0.5 to 6 mm is screened into multiple intermediate products of different particle size ranges. S2. The intermediate products are introduced into the magnetic separation device respectively; high-grade lithium ore can be obtained respectively.
2. The method for beneficiating coarse-grained lithium ore according to claim 1, characterized in that, In step S1, the raw materials are sieved into 0.5–3 mm and 3–6 mm.
3. The method for beneficiating coarse-grained lithium ore according to claim 1, characterized in that, The grade of the lithium ore raw material is 4-5% based on the mass fraction of Li2O.
4. The method for beneficiating coarse-grained lithium ore according to claim 1, characterized in that, The magnetic field strength during magnetic separation is 9000~11000 Oe.
5. The method for beneficiating coarse-grained lithium ore according to claim 1, characterized in that, The magnetic separation method adopted is dry belt high-intensity magnetic separation.
6. The method for beneficiating coarse-grained lithium ore according to claim 5, characterized in that, After multiple magnetic separations.
7. The method for beneficiating coarse-grained lithium ore according to claim 6, characterized in that, The coarser-grained intermediate products undergo three magnetic separations, while the finer-grained intermediate products undergo two magnetic separations.