A heavy medium main rewashing coal preparation system and process capable of balancing medium concentration

Abstract

The present invention relates to the technical field of coal production, and in particular to a heavy medium main-rewash coal preparation system and process capable of balancing medium concentration. The system comprises a main washing system, which is connected to a rewash system, and the rewash system comprises a rewash magnetic separator, which is connected to the rewash separation system via a rewash magnetic separation return medium pipeline. A main wash supplementary medium branch pipeline is provided on the rewash magnetic separation return medium pipeline, and the discharge port of the main wash supplementary medium branch pipeline is connected to the main washing system. The process steps include: (1) main wash high-density mixed medium separation; (2) main wash screening and medium removal; (3) main wash circulation return medium; (4) rewash low-density mixed medium separation; (5) rewash screening and medium removal; (6) rewash circulation return medium; and (7) balancing the main and rewash medium concentrations. The present invention diverts part of the medium recovered by the rewash system to the main washing system, thereby avoiding the main wash medium density reduction and rewash medium concentration increase caused by the main wash material carrying part of the medium, thereby making the coal preparation system more stable.

Description

Technical Field

[0001] The present invention relates to the technical field of coal production, and in particular to a heavy medium main rewashing coal preparation system and process capable of balancing medium concentration. Background Art

[0002] In the field of coal production technology, heavy medium main and re-washing coal preparation process is a commonly used coal preparation method. The heavy medium main and re-washing coal preparation process is divided into main washing and re-washing stages. The heavy medium coal preparation process is used to add raw coal containing gangue to a density of 1.8-1.9g / cm 3 The main washing is carried out in the heavy suspension (main washing high density medium) to separate the high density gangue to obtain coarse coal, and then add it to the density of 1.3-1.5g / cm 3 The clean coal is re-washed and separated in the re-suspension (re-wash low-density combined medium). The re-suspension is also called combined medium, which is a two-phase fluid with a certain density and in a suspended state, prepared by mixing the medium such as magnetic concentrate with water.

[0003] In the heavy medium main and rewashing coal preparation process, the coarse coal after the main washing needs to be removed by a vibrating screen before entering the rewashing system. However, the surface of the coarse coal will inevitably carry some media. After this part of the media enters the rewashing system, it will lead to an increase in the rewashing separation density and a decrease in the quality of the clean coal separated.

[0004] In order to maintain the medium balance of the main rewash system, part of the medium in the rewash system needs to be added back to the main washing system. The commonly used method in the existing technology is to directly transfer part of the rewash low-density mixed medium to the main wash high-density mixed medium. Although this method can transfer part of the medium in the rewash system to the main washing system, the transferred low-density mixed medium is mixed with the main wash high-density mixed medium, which will cause the density of the main wash high-density mixed medium to further decrease, and the amount of coal carried by the gangue separated in the main washing system to increase, which in turn leads to an increase in the use of raw coal, resulting in a waste of resources, and also a technical problem of increased medium loss. Summary of the Invention

[0005] In response to the technical problems in the prior art that coarse coal carries some media after the main washing, resulting in increased re-washing separation density and reduced clean coal quality, and directly transferring the re-washing low-density mixed media to the main washing high-density mixed media, resulting in reduced density of the main washing high-density mixed media, increased coal carried in gangue, waste of resources, and increased medium loss, the present invention provides a heavy medium main-rewashing coal separation system and process that can balance the medium concentration, and directly diverts part of the medium recovered by the re-washing magnetic separator to the main washing system through the main washing medium supplementary branch pipeline, while maintaining the medium balance and density stability of the main washing high-density mixed media and the re-washing low-density mixed media, thereby improving the quality of clean coal, reducing the amount of coal carried in gangue, and reducing medium loss.

[0006] In the first aspect, the present invention provides a heavy medium main-rewash coal preparation system that can balance the medium concentration, including a main washing system, the main washing system including a main washing sorting system and a main washing medium recovery system, the main washing sorting system is connected to the rewash system through a main washing material transportation channel, the rewash system including a rewash sorting system and a rewash medium recovery system, the feed port of the rewash sorting system is connected to the discharge port of the main washing material transportation channel, the rewash medium recovery system includes a rewash magnetic separator, the discharge port of the rewash magnetic separator is connected to the feed port of the rewash sorting system through a rewash magnetic separation return medium pipeline, a main wash medium supplement branch pipeline is provided on the rewash magnetic separation return medium pipeline, and the discharge port of the main wash medium supplement branch pipeline is connected to the feed port of the main washing sorting system.

[0007] Furthermore, the main wash sorting system includes a main wash combined medium barrel, the discharge port of the main wash combined medium barrel is connected to the feed port of the main wash cyclone, the upper discharge port of the main wash cyclone is connected to the main elution media screen, the main elution media screen is divided into the main elution media screen dry section and the main elution media screen wet section, and the main elution media screen is connected to the feed port of the main wash material transport channel; the main wash medium recovery system includes a main wash return medium pipeline and a main wash magnetic separator, the feed port of the main wash return medium pipeline is arranged under the main elution media screen dry section, the discharge port of the main wash return medium pipeline is connected to the feed port of the main wash combined medium barrel, the feed port of the main wash magnetic separator is arranged under the main elution media screen wet section, and the discharge port of the main wash magnetic separator is connected to the feed port of the main wash combined medium barrel through the main wash magnetic separation return medium pipeline.

[0008] Furthermore, the rewash sorting system includes a rewash combined medium barrel, the feed port of the rewash combined medium barrel is connected to the discharge port of the main wash material transport channel, the discharge port of the rewash combined medium barrel is connected to the feed port of the rewash cyclone, the upper discharge port of the rewash cyclone is connected to the rewash medium screen, and the rewash medium screen is divided into a rewash medium screen dry section and a rewash medium screen wet section; the rewash medium recovery system includes a rewash return medium pipeline and a rewash magnetic separator, and the rewash return medium pipeline The feed port is arranged under the dry section of the re-wash media screen, the discharge port of the re-wash return medium pipeline is connected with the feed port of the re-wash combined medium barrel, the feed port of the re-wash magnetic separator is arranged under the wet section of the re-wash media screen, the discharge port of the re-wash magnetic separator is connected with the feed port of the re-wash combined medium barrel through the re-wash magnetic separation return medium pipeline, the main wash supplementary medium branch pipeline is arranged on the re-wash magnetic separation return medium pipeline, and the discharge port of the main wash supplementary medium branch pipeline is connected with the feed port of the main wash combined medium barrel.

[0009] Furthermore, an automatic regulating valve is provided in the main wash medium supplement branch line, and a density meter is provided in the rewash medium combination barrel. When the density meter reading is greater than the set value, the automatic regulating valve is opened, and when the density meter reading is less than the set value, the automatic regulating valve is closed.

[0010] Furthermore, the automatic regulating valve is an electric valve or a pneumatic valve.

[0011] In a second aspect, the present invention provides a heavy medium main rewashing coal preparation process capable of balancing medium concentration, the steps comprising:

[0012] (1) Main wash high-density mixed medium separation: the main wash medium is mixed with water to form a main wash high-density mixed medium of a certain density, and gangue-containing coal material is added to the main wash high-density mixed medium for main wash separation to remove high-density gangue and obtain coarse coal-containing medium material;

[0013] (2) Main washing and screening, the coarse coal and media materials pass through the dry section and wet section of the main washing media screen in turn. The dry section screen is the main washing media screen and then the combined media, the wet section screen is the main washing thin media, and the coarse coal materials are on the screen;

[0014] (3) The main wash medium is recycled. The main wash medium after the main wash medium is directly added to the main wash high-density medium. The rewashed thin medium is separated by the main wash magnetic separator to obtain the main wash magnetic concentrate and add it to the main wash high-density medium. The remaining main wash coal slime is collected;

[0015] (4) Rewashing low-density mixed medium separation: the rewashing medium is mixed with water to prepare a rewashing low-density mixed medium with a certain density, coarse coal material is added to the rewashing low-density mixed medium, and rewashing and separation is performed to obtain clean coal-containing medium material;

[0016] (5) Re-washing and screening to remove media. The clean coal-containing media material passes through the dry section and wet section of the re-washing media screen in turn. The media under the dry section is the combined media after the re-washing media screen, the media under the wet section is the re-washed thin media, and the clean coal material is on the screen;

[0017] (6) Re-washing the medium back to the medium, the medium after the re-washing medium screen is directly added to the re-washing low-density medium, the re-washed dilute medium is separated by the re-washing magnetic separator, the re-washed magnetic concentrate is obtained and added to the re-washing low-density medium, and the remaining re-washed coal slime is collected;

[0018] (7) Balance the concentration of the main and rewash media, monitor the concentration of the rewash low-density medium in real time, and when the density of the rewash low-density medium is higher than the set value, divert part of the rewash magnetic concentrate separated by the rewash magnetic separator to the main wash high-density medium until the density of the rewash low-density medium is lower than the set value and stop diverting.

[0019] Furthermore, in step (1), the density of the main wash high density medium is 1.8-1.9 g / cm 3 ; In step (4), the low-density combined density of the washing medium is 1.3-1.5g / cm 3 .

[0020] Furthermore, the density of the main washing magnetic concentrate in step (3) is 1.9-2.3 g / cm 3 ; The density of the rewashed magnetic concentrate in step (6) is 1.9-2.3g / cm 3 .

[0021] Further, in step (7), when the density of the low-density composite medium is higher than 1.5 g / cm 3When the density of the rewashing low-density medium is lower than 1.3g / cm 3 Then stop diversion.

[0022] The beneficial effects of the present invention are:

[0023] (1) The present invention provides a heavy medium main-rewash coal preparation system and process that can balance the medium concentration. Part of the medium recovered by the rewash magnetic separator is directly diverted to the main wash system through the main wash supplementary medium branch pipe. The medium balance and density stability of the main wash high-density mixed medium and the rewash low-density mixed medium can be maintained at the same time, thereby improving the quality of clean coal, reducing the amount of coal carried by gangue, and reducing medium loss.

[0024] (2) The present invention can shorten the length of the main elution media screen wet section, reduce the amount of water sprayed in the main elution media screen wet section, and thus reduce the load of the main washing magnetic separator and further reduce the medium loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 This is a schematic structural diagram of the heavy medium main rewash coal preparation system capable of balancing the medium concentration in Example 1.

[0027] In the figure, 1-main wash combining barrel, 2-main wash cyclone, 3-main wash media screen dry section, 4-main wash media screen wet section, 5-main wash magnetic separator, 6-main wash return media pipeline, 7-main wash magnetic separation return media pipeline, 8-main wash material transportation channel, 9-re-wash combining barrel, 10-re-wash cyclone, 11-re-wash media screen dry section, 12-re-wash media screen wet section, 13-re-wash magnetic separator, 14-re-wash return media pipeline, 15-re-wash magnetic separation return media pipeline, 16-main wash make-up media branch pipeline. DETAILED DESCRIPTION

[0028] 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.

[0029] Example 1

[0030] A heavy medium main and rewash coal separation system capable of balancing medium concentration, comprising a main washing medium barrel 1, the discharge port of the main washing medium barrel 1 is connected to the feed port of the main washing cyclone 2, the upper discharge port of the main washing cyclone 2 is connected to the main elution medium screen, the main elution medium screen is divided into a main elution medium screen dry section 3 and a main elution medium screen wet section 4 in sequence, the feed port of the main washing return medium pipeline 6 is arranged under the main elution medium screen dry section 3, the discharge port of the main washing return medium pipeline 6 is connected to the feed port of the main washing medium barrel 1, the feed port of the main washing magnetic separator 5 is arranged under the main elution medium screen wet section 4, the discharge port of the main washing magnetic separator 5 is connected to the feed port of the main washing medium barrel through the main washing magnetic separation return medium pipeline 7, the discharge port of the main elution medium screen wet section 4 is connected to the feed port of the main washing material transport channel 8, and the feed port of the rewash medium barrel 9 is connected to the main washing material transport channel 8. The discharge port of the transport channel 8 is connected, the discharge port of the re-wash combined medium barrel 9 is connected to the feed port of the re-wash cyclone 10, the upper discharge port of the re-wash cyclone 10 is connected to the re-elution medium screen, the re-elution medium screen is divided into the re-elution medium screen dry section 11 and the re-elution medium screen wet section 12 in sequence, the feed port of the re-wash return medium pipeline 14 is arranged under the re-elution medium screen dry section 11, the discharge port of the re-wash return medium pipeline 14 is connected to the feed port of the re-wash combined medium barrel 9, the feed port of the re-wash magnetic separator 13 is arranged under the re-elution medium screen wet section 12, the discharge port of the re-wash magnetic separator 13 is connected to the feed port of the re-wash combined medium barrel 9 through the re-wash magnetic separation return medium pipeline 15, the main wash supplementary medium branch pipeline 16 is arranged on the re-wash magnetic separation return medium pipeline, and the discharge port of the main wash supplementary medium branch pipeline 16 is connected to the feed port of the main wash combined medium barrel 1.

[0031] Example 2

[0032] A heavy medium main rewash coal preparation process capable of balancing medium concentration using the system of Example 1 comprises the following steps:

[0033] (1) Main wash high-density mixed medium separation: mix the main wash medium with water and configure it to a density of 1.8-1.9g / cm 3 The main washing high-density mixed medium is added with gangue-containing coal material to the main washing high-density mixed medium, and the main washing and separation is carried out to remove the high-density gangue to obtain coarse coal-containing medium material;

[0034] (2) Main washing and screening, the coarse coal and media materials pass through the dry section and wet section of the main washing media screen in turn. The dry section screen is the main washing media screen and then the combined media, the wet section screen is the main washing thin media, and the coarse coal materials are on the screen;

[0035] (3) The main wash cycle returns the medium. The main wash medium is directly added to the main wash high density medium after the medium is screened. The rewashed thin medium is separated by the main wash magnetic separator to obtain a density of 1.9-2.3g / cm 3 Main wash magnetic concentrate and add it to the main wash high density medium, collect the remaining main wash coal slime;

[0036] (4) Rewash low-density medium separation, mix the rewash medium with water and configure it to a density of 1.3-1.5g / cm 3 Adding coarse coal material to the rewashed low-density mixed medium, rewashing and sorting, and obtaining clean coal-containing medium material;

[0037] (5) Re-washing and screening to remove media. The clean coal-containing media material passes through the dry section and wet section of the re-washing media screen in turn. The media under the dry section is the combined media after the re-washing media screen, the media under the wet section is the re-washed thin media, and the clean coal material is on the screen;

[0038] (6) Re-wash the media and return it to the circulating medium. After the re-washing and de-screening, the mixed medium is directly added to the re-wash low-density mixed medium. The re-washed thin medium is separated by the re-washing magnetic separator to obtain a density of 1.9-2.3g / cm 3 Rewash the magnetic concentrate and add it to the rewash low-density medium, and collect the remaining rewash slime;

[0039] (7) Balance the main rewash medium concentration and monitor the rewash low-density combined medium concentration in real time. When the rewash low-density combined medium density is higher than 1.5g / cm 3 At the same time, part of the rewash magnetic concentrate separated by the rewash magnetic separator is diverted to the main wash high-density medium until the density of the rewash low-density medium is lower than 1.3g / cm 3 Then stop diversion.

[0040] 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 main-rewash coal preparation system capable of balancing medium concentration, comprising a main washing system, the main washing system comprising a main washing and sorting system and a main washing medium recovery system, the main washing and sorting system being connected to the rewash system via a main washing material transport channel, the rewash system comprising a rewash sorting system and a rewash medium recovery system, the feed port of the rewash sorting system being connected to the discharge port of the main washing material transport channel, characterized in that: The rewash medium recovery system includes a rewash magnetic separator. The discharge port of the rewash magnetic separator is connected to the feed port of the rewash separation system through a rewash magnetic separation return medium pipeline. A main wash supplementary medium branch pipeline is provided on the rewash magnetic separation return medium pipeline. The discharge port of the main wash supplementary medium branch pipeline is connected to the feed port of the main wash separation system. The main washing and sorting system includes a main washing medium barrel (1), the discharge port of the main washing medium barrel (1) is connected to the feed port of the main washing cyclone (2), the upper discharge port of the main washing cyclone (2) is connected to the main elution medium screen, the main elution medium screen is divided into a main elution medium screen dry section (3) and a main elution medium screen wet section (4), the discharge port of the main elution medium screen wet section (4) is connected to the feed port of the main washing material transport channel (8); the main washing medium recovery system includes A main wash return medium pipeline (6) and a main wash magnetic separator (5), wherein the feed port of the main wash return medium pipeline (6) is arranged below the sieve of the main wash desorption medium screen dry section (3), the discharge port of the main wash return medium pipeline (6) is connected to the feed port of the main wash combination medium barrel (1), the feed port of the main wash magnetic separator (5) is arranged below the sieve of the main wash desorption medium screen wet section (4), and the discharge port of the main wash magnetic separator (5) is connected to the feed port of the main wash combination medium barrel through the main wash magnetic separation return medium pipeline (7); The rewashing and sorting system includes a rewashing combined medium barrel (9), the feed port of the rewashing combined medium barrel (9) is connected to the discharge port of the main washing material transport channel (8), the discharge port of the rewashing combined medium barrel (9) is connected to the feed port of the rewashing cyclone (10), the upper discharge port of the rewashing cyclone (10) is connected to the rewashing medium screen, and the rewashing medium screen is divided into a rewashing medium screen dry section (11) and a rewashing medium screen wet section (12); the rewashing medium recovery system includes a rewashing return medium pipeline (14) and a rewashing magnetic separator (13), the feed port of the rewashing return medium pipeline (14) is connected to the feed port of the rewashing cyclone (10), the upper discharge port of the rewashing cyclone (10) is connected to the rewashing medium screen, and the rewashing medium screen is divided into a rewashing medium screen dry section (11) and a rewashing medium screen wet section (12). The feed inlet is arranged under the sieve of the dry section (11) of the re-washing medium screen, the discharge port of the re-washing return medium pipeline (14) is connected to the feed inlet of the re-washing combined medium barrel (9), the feed inlet of the re-washing magnetic separator (13) is arranged under the sieve of the wet section (12) of the re-washing medium screen, the discharge port of the re-washing magnetic separator (13) is connected to the feed inlet of the re-washing combined medium barrel (9) through the re-washing magnetic separation return medium pipeline (15), the main wash supplementary medium branch pipeline (16) is arranged on the re-washing magnetic separation return medium pipeline, and the discharge port of the main wash supplementary medium branch pipeline (16) is connected to the feed inlet of the main wash combined medium barrel (1).

2. A heavy medium main rewash coal preparation system capable of balancing medium concentration according to claim 1, characterized in that: An automatic regulating valve is provided in the main wash medium supplement branch line (16), and a density meter is provided in the rewash medium combination barrel (9).

3. A heavy medium main rewash coal preparation system capable of balancing medium concentration according to claim 2, characterized in that: The automatic regulating valve is either an electric valve or a pneumatic valve.

4. A heavy medium main rewashing coal preparation process with balanced medium concentration according to claim 1, characterized in that the steps include: (1) Main washing high-density mixed medium separation: the main washing medium is mixed with water to form a main washing high-density mixed medium with a certain density, and coal containing gangue is added to the main washing high-density mixed medium for main washing separation to remove high-density gangue and obtain coarse coal containing medium material; (2) The coarse coal and media materials are screened and removed by the main washing media. The materials under the dry section are screened and then combined with the main washing media. The materials under the wet section are screened and removed by the main washing media. The materials above the screen are coarse coal materials. (3) The main washing medium is recycled. The mixed medium after the main washing medium is directly added to the main washing high-density mixed medium. The diluted medium is separated by the main washing magnetic separator to obtain the main washing magnetic concentrate and add it to the main washing high-density mixed medium. The remaining main washing coal slime is collected; (4) Rewashing low-density mixed medium separation: the rewashing medium is mixed with water to prepare a rewashing low-density mixed medium with a certain density, coarse coal material is added to the rewashing low-density mixed medium, and rewashing and separation is performed to obtain clean coal-containing medium material; (5) Re-washing and screening to remove media. The clean coal containing media materials pass through the dry section and wet section of the re-washing media screen in turn. The media under the dry section is the combined media after the re-washing media screen, the media under the wet section is the re-washing thin media, and the clean coal materials are on the screen; (6) Re-washing the media back to the recycling medium, the re-washing media after the media screen is directly added to the re-washing low-density combined medium, the re-washing dilute media is separated by the re-washing magnetic separator, the re-washing magnetic concentrate is obtained and added to the re-washing low-density combined medium, and the remaining re-washing coal slime is collected; (7) Balance the concentration of the main and rewash media, and monitor the concentration of the rewash low-density medium in real time. When the density of the rewash low-density medium is higher than the set value, divert part of the rewash magnetic concentrate separated by the rewash magnetic separator to the main wash high-density medium until the density of the rewash low-density medium is lower than the set value and stop diverting.

5. A heavy medium main rewashing coal preparation process capable of balancing medium concentration according to claim 4, characterized in that: The density of the main wash high density medium in step (1) is 1.8-1.9 g / cm 3 ; In step (4), the low-density composite density is 1.3-1.5g / cm 3 .

6. A heavy medium main rewashing coal preparation process capable of balancing medium concentration according to claim 4, characterized in that: The density of the main washing magnetic concentrate in step (3) is 1.9-2.3g / cm 3 ; The density of the rewashed magnetic concentrate in step (6) is 1.9-2.3g / cm 3 .

7. A heavy medium main rewashing coal preparation process capable of balancing medium concentration according to claim 4, characterized in that: In step (7), when the density of the low-density composite medium is higher than 1.5 g / cm 3 When the density of the rewashing low-density medium is lower than 1.3g / cm 3 Then stop diversion.

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