Roughing and pre-enriching method for iron lepidolite ore

Abstract

The method comprises the following steps that raw iron lepidolite is prepared into an iron lepidolite ore product with the particle size being-200 meshes and accounting for 60% + / -3%, ore pulp is prepared, the feeding concentration of the ore pulp is adjusted to be 11% + / -2%, magnetic separation and roughing are conducted on the ore pulp, and roughing and pre-enrichment of the iron lepidolite ore are completed. According to the roughing pre-enrichment method for the iron lepidolite ore, the lithium concentrate product with the high Li2O grade and the high recovery rate can be obtained by optimizing the concentration and the granularity of the fed ore and adopting one-stage roughing, and the method has the advantages of being simple in process, short in flow, low in energy consumption, low in cost, small in loss of fine-grain lithium metal, high in separation efficiency, good in separation effect, environmentally friendly, economical and the like; the method can be widely applied to pre-enrichment of the iron lepidolite ores, is beneficial to subsequent processing treatment, also remarkably reduces the processing and production cost, is high in use value and good in application prospect, and plays an important role in promoting wide application of different grades of iron lepidolite ores.

Description

Technical Field

[0001] The invention belongs to the field of lithium mineral processing magnetic separation and relates to a roughing pre-enrichment method for ferrolithium mica ore. Background Art

[0002] As an important lithium mineral resource, iron lithium mica ore has a high development and utilization value. However, most of the mined iron lithium mica ores have the following characteristics: low grade, severe weathering of lithium mica ore, complex ore-bearing form, and low theoretical grade of Li2O in lithium mica, which makes it difficult to efficiently recover lithium mica and various valuable components in iron lithium mica ore. In order to achieve efficient recovery of lithium mica and various valuable components in iron lithium mica ore, detailed mineral processing test research is needed. Among them, "early recovery when possible" is in line with the important concept of efficient recovery of useful minerals and energy conservation and emission reduction in mineral processing engineering, and the direct way to achieve this goal is to improve the recovery rate of concentrate in the roughing and pre-enrichment processes.

[0003] At present, froth flotation is the main beneficiation method for enriching and recovering lithium products. The original ore is crushed to a certain particle size and formed into slurry and transported to the flotation machine, and then the flotation agent is used to separate the lithium product from other minerals. However, this method generally has the phenomenon of mudification, which affects the grade and recovery rate of the flotation product, and the reagent residues can appear in the lithium product and the beneficiation wastewater, which is not conducive to the subsequent processing and environmental management of the product. It can be seen that flotation is not a preferred and ideal beneficiation method. Magnetic separation is a physical beneficiation method. There is no addition of chemical agents in the process. By applying a magnetic field, the iron lithium mica and other gangue minerals are magnetized to different degrees, so that they are subjected to different magnetic forces in the sorting space to produce different movement trajectories, thereby obtaining different magnetic products. However, in the process of grinding the iron lithium mica ore, there is a phenomenon of "over-grinding", and the distribution rate of iron lithium mica in the fine particle size (such as -500 mesh) produced by "over-grinding" is high, and the magnetic separation equipment has an unsatisfactory recovery effect on the products of these particle sizes, resulting in a serious "running ore" phenomenon in the existing magnetic separation process, which is difficult to improve. In addition, in order to overcome the above problems, the magnetic separation process of iron-lithium mica ore proposed by researchers generally includes roughing, scavenging and concentrating operations, but such magnetic separation process has the disadvantages of long process, long cycle, high energy consumption and high cost, and it is difficult to efficiently recover useful minerals in iron-lithium mica ore. In addition, in the existing magnetic separation and roughing process, a multi-stage magnetic separation and roughing method is usually used for pre-enrichment treatment, but such a method still has the disadvantages of long process, long cycle, high energy consumption, large loss of fine-grained lithium metal, low separation efficiency and poor separation effect. It is difficult to efficiently recover lithium resources from low-grade iron-lithium mica ore, and it is difficult to obtain high-grade lithium resources. At the same time, it does not conform to the green mineral processing concept of "early collection as much as possible" and energy conservation and emission reduction. Therefore, a roughing pre-enrichment method for iron-lithium mica ore with simple process, short flow, low energy consumption, low cost, small loss of fine-grained lithium metal, high sorting efficiency and good sorting effect is obtained, which plays an important role in efficiently recovering high-grade lithium concentrate products from low-grade iron-lithium mica ore and promoting the widespread application of iron-lithium mica ore. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a roughing pre-enrichment method for iron lithium mica ore with simple process, short flow, low energy consumption, low cost, small loss of fine-grained lithium metal, high sorting efficiency and good sorting effect.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A roughing pre-enrichment method for ferrolithium mica ore comprises the following steps: S1. The raw iron lithium mica ore is made into an iron lithium mica ore product with a particle size of -200 mesh accounting for 60%±3%; S2, preparing a slurry from the iron lithium mica ore product with a particle size of -200 meshes accounting for 60%±3% obtained in step S1; the feed concentration of the slurry is 11%±2%; S3, performing magnetic roughing on the ore pulp obtained in step S2 to complete the roughing pre-enrichment of the iron lithium mica ore.

[0007] The above-mentioned roughing pre-enrichment method of iron lithium mica ore is further improved, in step S1, the preparation method of the iron lithium mica ore product with a -200 mesh size accounting for 60%±3% comprises the following steps: S1-1, crushing and grinding the iron lithium mica ore; S1-2, classifying the ground product obtained in step S1-1 to obtain a ground product in which the -200 mesh size accounts for 60%±3%; S1-3, removing iron from the product with a -200 mesh size of 60%±3% obtained in step S1-2 to obtain a lithium iron mica ore product with a -200 mesh size of 60%±3%.

[0008] The above-mentioned roughing pre-enrichment method of iron lithium mica ore is further improved. In step S1-2, the grinding product of +200 mesh size obtained in the classification process is returned to step S1-1 for further crushing and grinding.

[0009] The above-mentioned roughing pre-enrichment method of iron lithium mica ore is further improved. In step S1-3, a weak magnetic separation device is used to remove iron from the product with a -200 mesh particle size of 60%±3% obtained in step S1-2 to remove magnetic iron in the product; the magnetic field strength is controlled to be 0.3T during the iron removal process.

[0010] The above-mentioned roughing pre-enrichment method of iron lithium mica ore is further improved, in which in step S1, the Li2O grade in the iron lithium mica ore is 0.25% to 0.75%.

[0011] The above-mentioned roughing pre-enrichment method of iron lithium mica ore is further improved. In step S2, the iron lithium mica ore product with a particle size of -200 mesh accounting for 60% obtained in step S1 is added to the ore feeding tank to prepare a slurry.

[0012] The above-mentioned roughing pre-enrichment method of ferrolithium mica ore is further improved. In step S3, a high gradient magnetic separator is used to perform magnetic roughing on the slurry obtained in step S2 to obtain a roughing concentrate.

[0013] The above roughing pre-enrichment method of ferrolithium mica ore is further improved in that in step S3, the magnetic roughing is a one-stage roughing.

[0014] The above-mentioned roughing pre-enrichment method of iron lithium mica ore is further improved. In step S3, during the magnetic roughing process, the magnetic field strength is 1.5T and the pulse frequency is 25Hz.

[0015] The above roughing pre-enrichment method of ferrolithium mica ore is further improved, and the recovery rate of the roughing concentrate is 65.6% to 78.7%.

[0016] Compared with the prior art, the advantages of the present invention are: Aiming at the shortcomings of the existing iron lithium mica magnetic roughing process, such as long processing flow, long cycle, high energy consumption, high cost, etc. due to serious "ore running away", and the inability to effectively enrich fine-grained lithium ore, resulting in large loss of fine-grained lithium metal, low sorting efficiency, poor sorting effect, etc., the present invention provides a roughing pre-enrichment method for iron lithium mica ore. By optimizing the operating parameters of the magnetic roughing process (feeding concentration, particle size, magnetic field strength, pulsation frequency), a one-stage magnetic roughing process can be adopted to obtain high recovery rate, high The rough selection of lithium concentrate with high grade is achieved by rough magnetic separation of ore pulp with a feed concentration of 11%±2% and a particle size of -200 mesh accounting for 60%±3%. Under the premise of ensuring the recovery rate of coarser-grained lithium products, it can also achieve effective enrichment of fine-grained lithium (-500 mesh) in the slurry. It can not only effectively overcome the phenomenon of magnetic material "running away" caused by "over-grinding", but also improve the recovery rate of magnetic materials and simplify the magnetic separation process, while meeting the production needs of "early recovery as possible" and energy saving and environmental protection. Compared with conventional two-stage or more magnetic roughing processes, the roughing pre-enrichment method of iron lithium mica ore of the present invention can obtain lithium concentrate products with high Li2O grade and recovery rate by optimizing feed concentration and particle size and adopting one-stage roughing, and has the advantages of simple process, short process, low energy consumption, low cost, small loss of fine-grained lithium metal, high sorting efficiency, good sorting effect, environmental protection and economy, etc. It is a new magnetic roughing method that can efficiently recover lithium resources from fine-grained low-grade iron lithium mica ore, can be widely used in the pre-enrichment of iron lithium mica ore, is not only conducive to subsequent processing, but also can significantly reduce the production cost of subsequent processing, has high use value, good application prospect, and plays an important role in promoting the wide application of iron lithium mica ores of different grades, especially low-grade iron lithium mica ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 The figure is a schematic diagram of the process flow of roughing and pre-enrichment of ferrolithium mica ore in Example 1 of the present invention.

[0019] Figure 2This is a schematic diagram of the process flow for roughing and pre-enrichment of iron lithium mica ore in Comparative Example 1.

[0020] Figure 3 This is a comparison chart of the rougher concentrate grade and recovery rate for different feed concentrations, different particle sizes, different magnetic field intensities, and different pulsation frequencies in Example 3 of the present invention. DETAILED DESCRIPTION

[0021] 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.

[0022] Example 1 A roughing pre-enrichment method for iron lithium mica ore, the process flow chart of which is as follows Figure 1 As shown, the following steps are included: S1. The raw iron lithium mica ore is made into an iron lithium mica ore product with a particle size of -200 mesh accounting for 60%, specifically: S1-1, crushing and grinding the iron lithium mica ore. In this step, the iron lithium mica ore used is the iron lithium mica ore from a mine in Hunan, and the average grade of Li2O in the ore is 0.451%.

[0023] S1-2, classifying the ground product obtained in step S1-1 to obtain a ground product in which the -200 mesh size accounts for 60%.

[0024] In step S1-2, the grinding product of +200 mesh size obtained in the classification process is returned to step S1-1 for further crushing and grinding.

[0025] S1-3, using weak magnetic separation equipment to remove iron from the product with a particle size of -200 meshes accounting for 60% obtained in step S1-2, controlling the magnetic field strength to 0.3T during the iron removal process, removing the magnetic iron in the product, and obtaining a lithium iron mica ore product with a particle size of -200 meshes accounting for 60%. In this step, the collected magnetic iron is combined with the tailings in the subsequent process for subsequent treatment.

[0026] S2. Add the iron lithium mica ore product with a particle size of -200 meshes accounting for 60% obtained in step S1 into a feed trough to prepare a slurry, and adjust the feed concentration in the slurry to 11%.

[0027] S3. Use a high gradient magnetic separator (LHGC-3000) to perform magnetic roughing (one-stage roughing) on ​​the slurry obtained in step S2. During the roughing process, the magnetic field strength is controlled to be 1.5 T and the pulse frequency is 25 Hz to obtain roughing concentrate and tailings, thereby completing the roughing pre-enrichment of the iron lithium mica ore.

[0028] Comparative Example 1 A roughing method for iron lithium mica ore, the process flow chart of which is as follows Figure 2 As shown, the following steps are included: S1. The raw iron lithium mica ore is made into an iron lithium mica ore product with a particle size of -200 mesh accounting for 80%, specifically: S1-1, crushing and grinding the iron lithium mica ore. In this step, the iron lithium mica ore used is the iron lithium mica ore from a mine in Hunan, and the average grade of Li2O in the ore is 0.451%.

[0029] S1-2, classifying the ground product obtained in step S1-1 to obtain a ground product in which the -200 mesh size accounts for 80%.

[0030] In step S1-2, the grinding product of +200 mesh size obtained in the classification process is returned to step S1-1 for further crushing and grinding.

[0031] S1-3, using weak magnetic separation equipment to remove iron from the product with a particle size of -200 meshes accounting for 80% obtained in step S1-2, controlling the magnetic field strength to 0.3T during the iron removal process, removing the magnetic iron in the product, and obtaining a lithium iron mica ore product with a particle size of -200 meshes accounting for 80%. In this step, the collected magnetic iron is combined with the tailings in the subsequent process for subsequent treatment.

[0032] S2. Add the iron lithium mica ore product with a particle size of -200 meshes accounting for 80% obtained in step S1 into a feed trough to prepare a slurry, and adjust the feed concentration in the slurry to 23%.

[0033] S3. Use a high gradient magnetic separator (LHGC-3000) to perform magnetic roughing (one-stage roughing) on ​​the ore pulp obtained in step S2. During the magnetic roughing process, the magnetic field strength is controlled to be 1.5 T to obtain roughing concentrate A and roughing tailings A.

[0034] S4. Use a high gradient magnetic separator (LHGC-3000) to perform magnetic roughing (two-stage roughing) on ​​the roughing tailings A obtained in step S3. During the magnetic roughing process, the magnetic field intensity is controlled to be 1.7 T to obtain roughing concentrate B and tailings.

[0035] In Comparative Example 1, rougher concentrate A and rougher concentrate B are mixed to obtain a rougher concentrate.

[0036] According to the process methods in Example 1 and Comparative Example 1, the iron lithium mica ore (original ore) was subjected to magnetic roughing separation for multiple times, and the average recovery results are shown in Table 1.

[0037] Table 1 Comparison of recovery results of different magnetic roughing processes in Example 1 and Comparative Example 1

[0038] Depend on Figure 1 and Figure 2 It can be seen that the conventional magnetic separation roughing process used in the comparative document 1 adopts two stages of roughing, wherein the magnetic field strength of the two stages of roughing is 1.5T and 1.7T. In contrast, the magnetic separation roughing process used in the embodiment 1 of the present invention adopts only one stage of roughing, and the magnetic field strength is 1.5T, which is less than or equal to the magnetic field strength required by the conventional magnetic separation equipment. By comparison, it can be seen that the process of the magnetic separation roughing process used in the embodiment of the present invention is shorter and has lower energy consumption.

[0039] It can be seen from Table 1 that, compared with the conventional magnetic roughing process adopted in Comparative Document 1, the one-stage magnetic roughing process adopted in Example 1 of the present invention can increase the grade of the roughing concentrate from 0.451% to 1.53%, while in Comparative Example 1 it can only be increased to 1.390%. It can be seen that the grade of the roughing concentrate obtained in Example 1 is 0.14% higher than that in Comparative Document 1, and a higher-grade lithium concentrate product can be obtained; at the same time, it can be seen from Table 1 that the yield and recovery rate of the roughing concentrate obtained in Example 1 of the present invention are 22.0% and 74.6%, respectively, which are increased by 7.7% and 30.6%, respectively, which are significantly better than Comparative Example 1.

[0040] It can be seen from the above results that, compared with the conventional magnetic roughing process, the one-stage magnetic roughing process adopted in Example 1 of the present invention can significantly improve the grade, yield and recovery rate of the roughing concentrate without increasing the number of process stages or other treatments, which is beneficial to subsequent processing, simplifies the original roughing process and reduces production costs.

[0041] Example 2 A roughing pre-enrichment method for iron lithium mica ore, specifically roughing pre-enrichment of iron lithium mica ores of different grades, comprising the following steps: S1. The raw iron lithium mica ore is made into an iron lithium mica ore product with a particle size of -200 mesh accounting for 60%, specifically: S1-1, crushing and grinding the iron lithium mica ore. In this step, the average grade of Li2O in the iron lithium mica ore used is 0.25% and 0.75%.

[0042] S1-2, classifying the ground product obtained in step S1-1 to obtain a ground product in which the -200 mesh size accounts for 60%.

[0043] In step S1-2, the grinding product of +200 mesh size obtained in the classification process is returned to step S1-1 for further crushing and grinding.

[0044] S1-3, using weak magnetic separation equipment to remove iron from the product with a particle size of -200 meshes accounting for 60% obtained in step S1-2, controlling the magnetic field strength to 0.3T during the iron removal process, removing the magnetic iron in the product, and obtaining a lithium iron mica ore product with a particle size of -200 meshes accounting for 60%. In this step, the collected magnetic iron is combined with the tailings in the subsequent process for subsequent treatment.

[0045] S2. Add the iron lithium mica ore product with a particle size of -200 meshes accounting for 60% obtained in step S1 into a feed trough to prepare a slurry, and adjust the feed concentration in the slurry to 11%.

[0046] S3. Use a high gradient magnetic separator (LHGC-3000) to perform magnetic roughing (one-stage roughing) on ​​the slurry obtained in step S2. During the roughing process, the magnetic field strength is controlled to be 1.5 T and the pulse frequency is 25 Hz to obtain roughing concentrate and tailings, thereby completing the roughing pre-enrichment of the iron lithium mica ore.

[0047] According to the process method in Example 2, the iron lithium mica ore (original ore) was subjected to magnetic roughing separation for multiple times, and the average recovery results are shown in Table 2.

[0048] Table 2 Comparison of recovery results of different grades of iron lithium mica ores by the magnetic roughing process used in Example 2 Feed grade / % Rough concentrate grade / % Rough concentrate yield / % Rough concentrate recovery rate / % Lowest grade 0.25 1.18 13.9 65.6 Highest grade 0.75 1.55 38.1 78.7 As shown in Table 2, the magnetic roughing process adopted in Example 2 of the present invention can be used to enrich iron lithium mica ores of different grades, and can ensure that the concentrate recovery rate is 65.6%~78.7%, which is much higher than the conventional roughing process. After using this process, there is no need to reprocess the roughing tailings, which greatly saves production costs.

[0049] Example 3 The effects of different magnetic roughing process operating parameters (feed concentration, particle size, magnetic field strength, pulsation frequency) on the recovery effect were investigated. Specifically, the effects of different feed concentrations, different particle sizes, different magnetic field strengths, and different pulsation frequencies on the roughing concentrate grade and recovery rate were investigated according to the process method in Example 1.

[0050] As shown in Table 3, the feed concentration was set to 7%, 11%, 15%, and 19%, the roughing feed particle size of -200 mesh accounted for 48%, 54%, 60%, and 66%, the magnetic field intensity was 1.3T, 1.4T, 1.5T, and 1.6T, and the pulsation frequency was 22Hz, 25Hz, 28Hz, and 31Hz to carry out a four-factor four-level orthogonal experiment.

[0051] Table 3 Orthogonal experimental design table

[0052] Figure 3This is a comparison chart of the roughing concentrate grade and recovery rate of different feed concentrations, different particle sizes, different magnetic field strengths, and different pulsation frequencies in Example 3 of the present invention. Figure 3 From the orthogonal test results, it can be seen that the feed concentration is 11%±2%, the particle size is -200 mesh, accounting for 60%±3%, the magnetic field strength is 1.5T, and the pulsation frequency is 25Hz. Under this condition, the first stage magnetic separation of iron lithium mica ore can maximize the recovery rate of lithium products while ensuring the Li2O grade in the lithium product as much as possible.

[0053] It can be seen from the above results that, compared with the conventional two-stage or more magnetic roughing process, the roughing pre-enrichment method of iron lithium mica ore of the present invention can obtain a lithium concentrate product with high Li2O grade and recovery rate by optimizing the feed concentration and particle size and adopting a one-stage roughing, and has the advantages of simple process, short process, low energy consumption, low cost, small loss of fine-grained lithium metal, high sorting efficiency, good sorting effect, environmental protection and economy, etc. It is a new magnetic roughing method that can efficiently recover lithium resources from fine-grained low-grade iron lithium mica ore, can be widely used in the pre-enrichment of iron lithium mica ore, is not only conducive to subsequent processing, but also can significantly reduce the production cost of subsequent processing, has high use value, good application prospects, and plays an important role in promoting the wide application of different grades of iron lithium mica ores, especially low-grade iron lithium mica ores.

[0054] 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 roughing pre-enrichment method for iron lithium mica ore, characterized in that: The following steps are involved: S1. The raw iron lithium mica ore is made into an iron lithium mica ore product with a particle size of -200 mesh accounting for 60%±3%; S2, preparing a slurry from the iron lithium mica ore product with a particle size of -200 meshes accounting for 60%±3% obtained in step S1; the feed concentration of the slurry is 11%±2%; S3, performing magnetic roughing on the ore pulp obtained in step S2 to complete the roughing pre-enrichment of the iron lithium mica ore.

2. The roughing pre-enrichment method of ferrolithium mica ore according to claim 1, characterized in that: In step S1, the method for preparing the iron lithium mica ore product with a -200 mesh size accounting for 60%±3% comprises the following steps: S1-1, crushing and grinding the iron lithium mica ore; S1-2, classifying the ground product obtained in step S1-1 to obtain a ground product in which the -200 mesh size accounts for 60%±3%; S1-3, removing iron from the product with a -200 mesh size of 60%±3% obtained in step S1-2 to obtain a lithium iron mica ore product with a -200 mesh size of 60%±3%.

3. The roughing pre-enrichment method of ferrolithium mica ore according to claim 2, characterized in that: In step S1-2, the grinding product of +200 mesh size obtained in the classification process is returned to step S1-1 for further crushing and grinding; In step S1-3, a weak magnetic separation device is used to remove iron from the product with a -200 mesh size of 60%±3% obtained in step S1-2, thereby removing magnetic iron from the product; the magnetic field strength is controlled to be 0.3T during the iron removal process.

4. The roughing pre-enrichment method of ferrolithium mica ore according to any one of claims 1 to 3, characterized in that: In step S1, the Li2O grade in the iron lithium mica ore is 0.25% to 0.75%.

5. The roughing pre-enrichment method of ferrolithium mica ore according to any one of claims 1 to 3, characterized in that: In step S2, the iron lithium mica ore product with a particle size of -200 mesh accounting for 60% obtained in step S1 is added to the ore feeding tank to prepare ore slurry.

6. The roughing pre-enrichment method of ferrolithium mica ore according to any one of claims 1 to 3, characterized in that: In step S3, a high gradient magnetic separator is used to perform rough magnetic separation on the ore pulp obtained in step S2 to obtain a rougher concentrate.

7. The roughing pre-enrichment method of ferrolithium mica ore according to claim 6, characterized in that: In step S3, the magnetic roughing selection is a one-stage roughing selection.

8. The roughing pre-enrichment method of ferrolithium mica ore according to claim 7, characterized in that: In step S3, during the rough magnetic separation process, the magnetic field strength is 1.5 T and the pulse frequency is 25 Hz.

9. The roughing pre-enrichment method of ferrolithium mica ore according to claim 8, characterized in that: The recovery rate of the rougher concentrate is 65.6% to 78.7%.

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