A heavy medium coal preparation ultra-low dielectric loss control process

Abstract

The present invention relates to the field of heavy medium coal preparation technology, specifically to a heavy medium coal preparation process with ultra-low dielectric loss control. By analyzing the flow direction of magnetic separator tailings, magnetic separation is performed on materials with high dielectric content and appropriate concentrations, such as laminated undersize, centrifuge filtrate, and high-frequency undersize, while maintaining the original material flow path and reducing dielectric consumption. The heavy medium coal preparation process can reduce the dielectric content of coal slime to approximately 500g / t and reduce the dielectric loss of the coal preparation system from 0.8g / t to <0.6g / t, achieving ultra-low dielectric loss control.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy medium coal preparation, and in particular to an ultra-low dielectric loss control process for heavy medium coal preparation. Background Art

[0002] The mainstream production process in heavy medium coal preparation plants involves using shallow trough separators and heavy medium cyclones to separate lump coal. Magnetite powder is primarily used as the separation medium in the heavy medium suspension. Dense medium separation plants experience medium losses in clean coal, middlings, gangue, and coal slime products. Slime carryover is the dominant medium, typically around 1000g / t. Slime carryover primarily originates from tailings from various magnetic separators. Therefore, the small amount of medium present in the tailings is the primary cause of medium loss.

[0003] The heavy media system uses a de-mediating screen to process product categories. The media recovery process involves magnetic separators to recover the dilute and combined media sections of the de-mediating screen. This process is performed using a main wash magnetic separator, a gangue magnetic separator, a medium coal magnetic separator, and a clean coal magnetic separator. The concentrate from the magnetic separator enters a qualified media drum to replenish the qualified media density. The magnetic separator tailings, depending on their ash content, enter the coal slime drum, the TBS separator concentrate drum, or the tailings drum. The residual media in the magnetic separator tailings cannot be effectively recycled, typically around 1000g / t. Instead, through grading and sorting, it ultimately accumulates in the coarse slime tailings high-frequency screen underflow, the coarse slime concentrate stacked screen underflow, and the centrifuge filtrate. This leads to media carryover in these materials, generally exceeding 2000-4000g / t, a primary cause of high coal slime media carryover. Therefore, a process with ultra-low media consumption control is designed to fully recover the magnetic separator tailings media, improve product quality, and control production costs. Summary of the Invention

[0004] In response to technical problems such as heavy medium loss, the present invention provides an ultra-low medium consumption control process for heavy medium coal preparation, which achieves ultra-low consumption control of heavy medium.

[0005] The present invention provides an ultra-low medium consumption control process for heavy medium coal separation. After the main washing clean coal, medium coal, gangue and clean coal pass through the de-mediating screen, the dilute medium generated enters the main washing magnetic separator, medium coal magnetic separator, gangue magnetic separator and clean coal magnetic separator for magnetic separation respectively, comprising the following steps:

[0006] (1) The tailings slime produced by the main washing magnetic separator and the medium coal magnetic separator is classified by the grading cyclone. The overflow material on the grading cyclone enters the flotation, and the material at the bottom of the grading cyclone enters the TBS separator for sorting;

[0007] (2) The TBS concentrate produced at the top of the TBS separator is combined with the tailings produced by the clean coal magnetic separator and then enters the product cyclone for classification. The overflow of the product cyclone enters the flotation process, and the material at the bottom of the product cyclone enters the laminated screen for screening.

[0008] (3) The tailings produced at the bottom of the TBS separator are combined with the tailings produced by the gangue magnetic separator and enter the gangue cyclone for classification. The material on the top of the gangue cyclone overflows into the thickening tank, and the material at the bottom of the product cyclone enters the high-frequency screen for screening;

[0009] (4) The material on the laminated screen in step (2) enters the TBS concentrate centrifuge, the centrifuge liquid of the TBS concentrate centrifuge and the liquid under the laminated screen enter the magnetic separator A for magnetic separation, and the muddy water produced by the magnetic separator A enters the flotation;

[0010] (5) The liquid under the high frequency screen in step (3) enters the magnetic separator B for magnetic separation, and the muddy water produced by the magnetic separator B enters the concentration tank.

[0011] Furthermore, the heavy media produced by the main washing magnetic separator, the medium coal magnetic separator, the gangue magnetic separator and the clean coal magnetic separator are all pumped into the combined medium barrel.

[0012] Furthermore, in step (1), the tailings coal slime produced by the main washing magnetic separator and the medium coal magnetic separator is first stored in a coal slime barrel.

[0013] Furthermore, in step (2), the TBS concentrate produced in the upper part of the TBS separator is first stored in a TBS concentrate barrel.

[0014] Furthermore, in step (3), the tailings generated at the bottom of the TBS separator are first stored in the TBS tailings barrel.

[0015] Furthermore, in step (4), the solid obtained by centrifugation in the TBS concentrate centrifuge is a clean coal product.

[0016] Furthermore, in step (5), the material on the high-frequency screen is a medium coal product.

[0017] Furthermore, the heavy medium is magnetite powder with a density of 4.5 g / cm 3 .

[0018] The mechanism of the present invention is that medium loss in heavy medium coal separation occurs in clean coal, medium coal, gangue, and coal slime products. Among them, the coal slime product carries the majority of the medium, generally around 1000g / t. The coal slime product carries the medium mainly from the tailings of each magnetic separator. Therefore, the small amount of medium present in the magnetic separator tailings is the main cause of medium loss. The present invention analyzes the flow direction of the magnetic separator tailings and magnetically recovers the materials with high medium carryover and appropriate concentration, such as the laminated screen, centrifuge filtrate water, and high-frequency screen, while maintaining the original material flow direction and reducing medium consumption.

[0019] The beneficial effect of the present invention is that the heavy medium coal preparation process of the present invention can reduce the medium content of coal slime to about 500g / t, and reduce the medium consumption of the coal preparation system from 0.8g / t to <0.6g / t, thereby achieving ultra-low medium consumption control. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 It is a process flow chart of a specific embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0023] Example 1

[0024] Combine Figure 1 In the ultra-low medium consumption control process for heavy medium coal preparation described in the present invention, after the main washing clean coal, medium coal, gangue and clean coal pass through the de-mediating screen, the dilute medium generated enters the main washing magnetic separator, medium coal magnetic separator, gangue magnetic separator and clean coal magnetic separator for magnetic separation respectively, and the heavy medium generated by the main washing magnetic separator, medium coal magnetic separator, gangue magnetic separator and clean coal magnetic separator is all pumped into a qualified combined medium barrel.

[0025] The specific steps include:

[0026] (1) The tailings slime produced by the main washing magnetic separator and the medium coal magnetic separator is stored in the slime barrel and then classified by the grading cyclone. The overflow of the grading cyclone enters the flotation, and the material at the bottom of the grading cyclone enters the TBS separator for sorting;

[0027] (2) The TBS concentrate produced at the top of the TBS separator is first stored in the TBS concentrate barrel, then combined with the tailings produced by the clean coal magnetic separator and sent to the product cyclone for classification. The overflow of the product cyclone is sent to flotation, and the material at the bottom of the product cyclone is sent to the laminated screen for screening.

[0028] (3) The tailings produced at the bottom of the TBS separator are first stored in the TBS tailings barrel, and then combined with the tailings produced by the gangue magnetic separator and enter the gangue cyclone for classification. The material overflowing from the upper part of the gangue cyclone enters the thickening tank, and the material at the bottom of the product cyclone enters the high-frequency screen for screening;

[0029] (4) The material on the laminated screen in step (2) enters the TBS concentrate centrifuge, the centrifuge liquid of the TBS concentrate centrifuge and the liquid under the laminated screen enter the magnetic separator A for magnetic separation, the solid obtained by centrifugation of the TBS concentrate centrifuge is the clean coal product, and the muddy water produced by the magnetic separator A enters the flotation;

[0030] (5) The liquid under the high-frequency screen in step (3) enters the magnetic separator B for magnetic separation, the material over the high-frequency screen is the medium coal product, and the muddy water produced by the magnetic separator B enters the concentration tank.

[0031] When installing the equipment of the present invention, the pipelines should be arranged based on full utilization of the height difference to ensure that the tailings and under-screen water materials of each magnetic separator flow into the feed material by gravity, thereby avoiding increasing the power consumption of the system.

[0032] The heavy medium used in the present invention is magnetite powder with a density of 4.5g / cm 3 The medium content of the muddy water produced by magnetic separator A and the muddy water produced by magnetic separator B was reduced to 0.10g / L.

[0033] The ultra-low medium consumption control process for heavy medium coal preparation described in the present invention can effectively improve the system's medium recovery efficiency, reduce the medium content of the coal slime product in the heavy medium coal preparation plant from 1000g / t to about 500g / t, and reduce the medium consumption of the coal preparation system from 0.8g / t to <0.6g / t, thereby enhancing the density stability of qualified media, reducing medium consumption, and saving production costs.

[0034] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A heavy medium coal separation process with ultra-low medium consumption control, wherein the main washed clean coal, middling coal, gangue and clean coal are separated by a de-mediating screen, and the resulting dilute medium enters the main washing magnetic separator, middling coal magnetic separator, gangue magnetic separator and clean coal magnetic separator for magnetic separation, characterized in that: The steps include: (1) The tailings slime produced by the main washing magnetic separator and the medium coal magnetic separator is first stored in the slime barrel, and then classified by the grading cyclone. The overflow of the grading cyclone enters the flotation, and the material at the bottom of the grading cyclone enters the TBS separator for sorting; (2) The TBS concentrate produced at the top of the TBS separator is first stored in the TBS concentrate barrel, then combined with the tailings produced by the clean coal magnetic separator and sent to the product cyclone for classification. The overflow of the product cyclone is sent to flotation, and the material at the bottom of the product cyclone is sent to the laminated screen for screening. (3) The tailings generated at the bottom of the TBS separator are first stored in the TBS tailings barrel, and then merged with the tailings generated by the gangue magnetic separator and entered into the gangue cyclone for classification. The material overflowing from the upper part of the gangue cyclone enters the thickening tank, and the material at the bottom of the product cyclone enters the high-frequency screen for screening; In step (2), the material on the laminated screen enters the TBS concentrate centrifuge, the centrifuge liquid of the TBS concentrate centrifuge and the liquid under the laminated screen enter the magnetic separator A for magnetic separation, and the muddy water produced by the magnetic separator A enters the flotation; In step (3), the liquid under the high-frequency screen enters the magnetic separator B for magnetic separation, and the muddy water produced by the magnetic separator B enters the concentration tank.

2. The ultra-low dielectric loss control process for heavy medium coal preparation according to claim 1, characterized in that: The heavy media produced by the main washing magnetic separator, medium coal magnetic separator, gangue magnetic separator and clean coal magnetic separator are all pumped into the combined media barrel.

3. The ultra-low dielectric loss control process for heavy medium coal preparation according to claim 1, characterized in that: In step (2), the solid obtained by centrifugation of the TBS concentrate centrifuge is the clean coal product.

4. The ultra-low dielectric loss control process for heavy medium coal preparation according to claim 1, characterized in that: In step (3), the material on the high-frequency screen is the medium coal product.

5. The ultra-low dielectric loss control process for heavy medium coal preparation according to claim 1, characterized in that: The heavy medium is magnetite powder with a density of 4.5g / cm 3 .

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