A beneficiation method for recovering mica powder from tailings

Abstract

The present invention discloses a beneficiation method for recovering mica powder from tailings. The physical beneficiation recovery process of "screening and classification - discarding of fine-grained tailings - beneficiation of narrow particle size fractions" is adopted. Through steps such as screening and classification, discarding of fine-grained tailings, and beneficiation of narrow particle size fractions by gravity separation, the processing volume of the gravity separation process is reduced, and the separation efficiency of the gravity separation operation is significantly improved, and mica powder concentrate products with better quality can be obtained. The technological process has a simple structure, and has the advantages of low equipment investment and low beneficiation cost; at the same time, no chemical reagents need to be added, and the tail water can be directly recycled, which is beneficial to the construction of green mines.

Description

Technical Field

[0001] The present invention belongs to the technical field of beneficiation and recovery of mica powder, and particularly relates to a beneficiation method for recovering mica powder from tailings. Background Art

[0002] With the large-scale development of mineral resources, a huge amount of mine solid waste - tailings has been generated. Recycling the useful components in tailings can not only effectively alleviate the shortage of resources, improve the resource utilization efficiency, but also reduce the tailings storage, mitigate the pollution of heavy metal ions in tailings to the environment, and maximize the avoidance of disasters such as landslides and collapses.

[0003] Mica is a silicate mineral with a layered structure and is one of the main rock-forming minerals, presenting a hexagonal flake crystal form and being widely used in industries such as rubber, plastics, coatings, paints, ceramics, thermal insulation, cosmetics, pigments, papermaking, and metallurgy. Most of the tailings from metamorphic rock mines contain a large amount of mica resources, and most of them are stored in tailings ponds without being recycled.

[0004] Currently, the main methods for mica recovery are flotation and air separation processes. The flotation method requires using cationic collectors such as long-chain carbon chain acetate amines and anionic collectors such as fatty acids. Mica, as a foam product, needs to go through three rough selections and two fine selections to effectively separate mica from gangue and obtain qualified mica concentrate. The general process flow of mica air separation method is: crushing - screening and classification - air separation. After the ore is crushed by a jaw crusher, mica presents a flaky shape, while minerals such as feldspar and quartz present blocky particles. Then, the minerals of different particle sizes are screened and classified by a circular vibrating screen, and the selected materials are preselected into relatively narrow particle sizes and separated by a special air separation device. Currently, the main methods for mica recovery are flotation and air separation processes. The flotation method requires using cationic collectors such as long-chain carbon chain acetate amines and anionic collectors such as fatty acids. Mica, as a foam product, needs to go through three rough selections and two fine selections to effectively separate mica from gangue and obtain qualified mica concentrate. The general process flow of mica air separation method is: crushing - screening and classification - air separation. After the ore is crushed by a jaw crusher, mica presents a flaky shape, while minerals such as feldspar and quartz present blocky particles. Then, the minerals of different particle sizes are screened and classified by a circular vibrating screen, and the selected materials are preselected into relatively narrow particle sizes and separated by a special air separation device.

[0005] In addition, there are also patented technologies that obtain high-quality mica concentrate only through physical beneficiation. For example, the patent number is CN2017110361207, which is a beneficiation method for recovering mica from copper mine tailings. This patented technology uses the operation steps of grinding, weak and strong magnetic separation, classification, and gravity separation. It separates iron by weak magnetic separation, separates weakly magnetic mica minerals and non-magnetic gangue minerals by strong magnetic separation, and screens out mica concentrate through classification and gravity separation. The mica concentrate content is more than 77%, and the mica recovery rate can reach more than 40%. This patent significantly reduces the operating cost and also avoids environmental pollution. However, the steps of this patent still have problems of high energy consumption and complexity.

[0006] In view of this, the present invention provides a beneficiation method that can obtain a high mica concentrate content and mica recovery rate only through "screening and classification - discarding of fine particle size - narrow particle size gravity separation", which has the characteristics of simple steps, low energy consumption, and good beneficiation separation effect, and is very suitable for actual promotion and use in mines. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a beneficiation method for recovering mica powder from tailings.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A beneficiation method for recovering mica powder from tailings, comprising the following steps:

[0010] (1) Screening and classification: The tailings are made into pulp for screening and classification. Among them, after screening and classification, two particle sizes of -0.045 - 0.058 mm and +0.045 - 0.058 mm are obtained, and the +0.045 - 0.058 mm particle size is divided into two or more particle sizes;

[0011] (2) Discarding of fine particle size: The -0.045 - 0.058 mm particle size is directly used as tailings and discarded in advance;

[0012] (3) Gravity separation of particle sizes: All particle sizes in the +0.045 - 0.058 mm particle size are respectively subjected to gravity separation to obtain mica concentrate and tailings of different particle sizes.

[0013] Further, in step (3), the tailings of each coarse particle size are combined with the tailings screened and discarded to form total tailings. The mica concentrate of each particle size can be combined into total mica concentrate, or the mica concentrate of each particle size can be used as mica concentrate powder products of different particle sizes and different purities.

[0014] Further, in step (1), the mass percentage concentration of the pulp is 15 - 50%.

[0015] Further, in step (1), the +0.045 to 0.058 mm particle size fraction is divided into two particle size fractions: +0.045 to 0.058 mm - 0.106 to 0.15 mm and +0.106 to 0.15 mm.

[0016] Further, the +0.045 to 0.058 mm - 0.106 to 0.15 mm particle size fraction is divided into 2 to 4 narrow particle size fractions. The specific number of narrow particle size fractions into which the particle size is segmented should be determined based on the measured particle size distribution data of the tailings to be processed and combined with specific test results.

[0017] Further, in step (1), at least one of a hydrocyclone, a spiral classifier, and a high-frequency vibrating screen is selected for screening and classification.

[0018] Further, in step (3), at least one of an industrial model shaking table, a hydrocyclone, a spiral concentrator, and a spiral launder is selected for particle size gravity separation.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The new beneficiation method of "screening and classification - tailing rejection of fine particle size fraction - gravity separation of narrow particle size fraction" adopted by the present invention is based on the characteristics of mica itself. Flaky mica has a higher content in the coarse particle size fraction and a lower content in the fine particle size fraction, and the gravity separation efficiency of the fine particle size fraction is extremely low, making it difficult to select mica concentrate with good quality. Therefore, the finest -0.045 to 0.058 mm particle size fraction is directly rejected as tailings, which can reduce the material handling volume of the gravity separation operation; the remaining coarse particle size fractions are respectively subjected to gravity separation of narrow particle size fractions to recover mica. The relatively narrow particle size distribution is beneficial to improving the gravity separation efficiency, obtaining mica powder concentrate products with good quality, and mica concentrate with higher purity can be selected from the tailings with coarser particle sizes. This process has the advantages of simple process structure, low equipment investment, and low beneficiation cost.

[0021] 2. The new beneficiation method of "screening and classification - tailing rejection of fine particle size fraction - gravity separation of narrow particle size fraction" adopted by the present invention does not require the addition of any chemical agents. Therefore, the water after filtration of the concentrate and tailings and the flushing water can all be returned as recycled water for reuse, and no secondary pollution to the environment will be caused.

[0022] 3. The new beneficiation method of "screening and classification - tailing rejection of fine particle size fraction - gravity separation of narrow particle size fraction" adopted by the present invention can obtain mica concentrate products with good quality, enabling better utilization of a large amount of mine tailings resources that cannot be effectively recovered and utilized under the existing technical level. It can not only effectively alleviate the shortage of resources, improve the resource utilization efficiency, but also reduce the tailings stockpile, which is beneficial to the improvement of the mine ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a process flow diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0025] Example 1

[0026] The copper - selecting tailings of a large domestic copper mine tailings pond contain 86.64% of silicate minerals such as quartz, feldspar, mica, and clay minerals, among which the mica content is 48.42%. Using the process technology of the present invention, the following steps are carried out, as Figure 1 :

[0027] (1) Screening and classification: Adjust the tailings pulp concentration to 30%, and carry out screening and classification through a high - frequency vibrating screen, dividing it into four particle sizes: - 0.051mm, + 0.051mm - 0.075mm, + 0.075mm - 0.106mm, and + 0.106mm;

[0028] (2) Discarding of fine - sized tailings: The yield of the - 0.051mm fine - sized fraction is 42.12%, and the mica content is 26.56%. It does not enter the gravity separation operation and is directly discarded as fine - sized tailings in advance;

[0029] (3) Narrow - sized gravity separation: Carry out shaking table gravity separation on the three narrow - sized fractions of + 0.051mm - 0.075mm, + 0.075mm - 0.106mm, and + 0.106mm respectively to obtain mica concentrates and tailings of three particle sizes. The tailings of the three coarse - sized fractions are combined with the fine - sized tailings discarded by screening to form the total tailings, and the concentrates of the three particle sizes are combined into one mica concentrate.

[0030] Finally, a mica concentrate powder product with a mica content of 64.33% and a mica recovery rate of 76.90% is obtained. Among them, the mica content in the mica concentrate of the + 0.051mm - 0.075mm particle size is 56.28%, and the mica recovery rate is 17.76%; the mica content in the mica concentrate of the + 0.075mm - 0.106mm particle size is 61.36%, and the mica recovery rate is 31.26%; the mica content in the mica concentrate of the + 0.106mm particle size is 75.29%, and the mica recovery rate is 27.88%.

[0031] Example 2

[0032] The iron - selecting tailings of a large domestic iron mine contain 88.5% of silicate minerals such as quartz, feldspar, mica, and clay minerals, among which the mica content is 47.50%. Using the process technology of the present invention, the following steps are carried out, as Figure 1 :

[0033] (1) Screening and classification: Adjust the concentration of the tailings pulp to 35%, and conduct screening and classification through a high-frequency vibrating screen, dividing it into four particle sizes: -0.045mm, +0.045mm - 0.075mm, +0.075mm - 0.106mm, and +0.106mm;

[0034] (2) Discarding of fine particle size: The yield of the -0.045mm fine particle size is 34.56%, and the mica content is 16.45%. It does not enter the gravity separation operation and is directly discarded as fine particle size tailings in advance;

[0035] (3) Narrow particle size gravity separation: Conduct shaking table gravity separation on the three narrow particle sizes of +0.045mm - 0.075mm, +0.075mm - 0.106mm, and +0.106mm respectively to obtain mica concentrates and tailings of three particle sizes. The tailings of the three coarse particle sizes are combined with the fine particle size tailings discarded by screening to form the total tailings, and the concentrates of the three particle sizes are combined into one mica concentrate.

[0036] Finally, a mica concentrate powder product with a mica content of 63.9% and a mica recovery rate of 88.31% is obtained. Among them, the mica content in the mica concentrate of the +0.045mm - 0.075mm particle size is 54.15%, and the mica recovery rate is 17.02%; the mica content in the mica concentrate of the +0.075mm - 0.106mm particle size is 62.45%, and the mica recovery rate is 38.80%; the mica content in the mica concentrate of the +0.106mm particle size is 73.58%, and the mica recovery rate is 30.19%.

[0037] Comparative Example 1

[0038] Comparative Example 1 is the content of Example 1 recorded in Patent CN2017110361207, a beneficiation method for recovering mica from copper mine tailings. The final high-quality mica concentrate obtained in Example 1 of this patent has a mica content of 81.54% and a mica recovery rate of 41.8%.

[0039] Comparative Example 2

[0040] The tailings processed in Comparative Example 2 are the same as those in Example 1. The difference lies in the beneficiation method. Specifically, when conducting screening and classification in Comparative Example 2, it is divided into two particle sizes: -0.045mm and +0.045mm; the -0.045mm particle size is directly discarded as fine particle size tailings in advance; the +0.045mm particle size is subjected to gravity separation.

[0041] When the +0.045mm particle size is subjected to gravity separation, a mica concentrate powder product with a mica content of 51.47% and a mica recovery rate of 66.39% is obtained.

[0042] It can be seen from Example 1 and Comparative Examples 1-2 that compared with Patent CN2017110361207, the present invention obviously has the characteristics of simple steps, low energy consumption and high recovery rate; compared with Comparative Example 2, it shows that narrow particle size gravity separation is beneficial to improve the mica content and recovery rate in mica concentrate powder.

[0043] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And the changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention should all be within the protection scope of the appended claims of the present invention.

Claims

1. A beneficiation method for recovering mica powder from tailings, characterized in that, It consists of the following steps: (1) Screening and classification: After making the tailings into pulp, they are screened and classified by screening equipment. Among them, two particle sizes of -0.045mm and +0.045mm are obtained after screening and classification, and the +0.045mm particle size is divided into two or more particle sizes; (2) Discarding of fine particle size: The -0.045mm particle size is directly discarded as tailings in advance; (3) Gravity separation by particle size: All particle sizes in the +0.045mm particle size are respectively subjected to rough gravity separation and scavenging gravity separation, and mica concentrates and tailings of different particle sizes are obtained according to the specific gravity difference.

2. The ore dressing method for recovering mica powder from tailings according to claim 1, characterized in that, In step (3), the mica concentrates of each particle size are combined into the total mica concentrate, and the mica concentrates of each particle size are used as mica concentrate powder products of different particle sizes and different purities.

3. The ore dressing method for recovering mica powder from tailings according to claim 1, characterized in that, In step (1), the mass percentage concentration of the pulp is 15 - 50%.

4. A beneficiation method for recovering mica powder from tailings according to claim 1, characterized in that, In step (1), the +0.045mm particle size is divided into two particle sizes of +0.045mm - 0.106mm and +0.106mm.

5. The ore dressing method for recovering mica powder from tailings according to claim 4, characterized in that, In step (1), the particle size of +0.045mm - 0.106mm is divided into 2 - 3 narrow particle sizes.

6. A beneficiation method for recovering mica powder from tailings according to any one of claims 1-5, characterized in that, In step (1), at least one of a hydrocyclone, a spiral classifier, and a high-frequency vibrating screen is selected for screening and classification.

7. A beneficiation method for recovering mica powder from tailings according to any one of claims 1-5, characterized in that, In step (3), at least one of an industrial model shaking table, a hydrocyclone, a spiral concentrator, and a spiral chute is selected for gravity separation by particle size.

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