UNDERGROUND COAL HYPERGRAVITY FIELD SEPARATION SYSTEM AND SEPARATION PROCESS

Abstract

The present disclosure relates to the field of mineral processing and separation, and in particular, to an underground coal hypergravity field separation system and a separation process. The separation system includes a grading hydrocyclone group, hypergravity field separators, feeding pumps, and conveying pumps. Coal collected underground is graded through a grading hydrocyclone first, then is fed into the hypergravity field separators for separation, and finally, is conveyed to a next link for dehydration through the conveying pumps. The separation system of the present disclosure has less supporting equipment, small floor area, and no complex pipeline, and is suitable for a downhole operation. In addition, the hypergravity field separators can provide a high-strength centrifugal acceleration, which can realize rapid separation of coal gangue particles in a radial direction and a tangential direction, and realize effective separation of fine coal gangue particles.

Claims

1. An underground coal hypergravity field separation system comprising a grading hydrocyclone group, conveying pumps, feeding pumps, and at least two hypergravity field separators, wherein: the grading hydrocyclone group comprises a feeding pipe, an overflow port, and an underflow port; the hypergravity field separator comprises a floating object discharging port and a sediment discharging port; the feeding pipe of the hypergravity field separator is connected to a raw coal conveying pipe; the overflow port and the underflow port of the grading hydrocyclone group are respectively connected to feeding ports of the two hypergravity field separators through feeding pumps; the floating object discharging ports of the two hypergravity field separators are respectively connected to clean coal conveying pipes through the conveying pumps; and the sediment discharging ports of the two hypergravity field separators are connected to gangue conveying pipes through the conveying pumps.

2. The underground coal hypergravity field separation system according to claim 1, wherein: the hypergravity field separator comprises a rotating drum; a rotor is arranged at a bottom end inside the rotating drum; a floating object discharging port is formed in an upper part of the rotating drum; and a sediment discharging port is formed in a lower part of the rotating drum.

3. The underground coal hypergravity field separation system according to claim 2, wherein the rotor is used to provide a centrifugal acceleration of 300 times the gravitational acceleration for a material entering the rotating drum.

4. A coal separation process based on the underground coal hypergravity field separation system, comprising the following steps: raw coal screening and breaking, the raw coal screening and breaking comprising: adopting a 6 mm screening standard for raw coal; conveying an undersized product smaller than 6 mm to a grading hydrocyclone group; conveying an oversized product greater than or equal to 6 mm to a crushing machine; crushing the oversized product into particles smaller than 6 mm; and returning the particles to a screening process; raw coal grading comprising: conveying the raw coal smaller than 6 mm to the grading hydrocyclone group; taking 1 mm as a grading standard; discharging coarse particles of 1-6 mm from an underflow port of the grading hydrocyclone group; conveying the particles to a hypergravity field separator corresponding to the underflow port; discharging a fine particle product smaller than 1 mm from an overflow port of the grading hydrocyclone group; and conveying the particles to a hypergravity field separator corresponding to the overflow port; raw coal separation comprising: feeding the raw coal smaller than 1 mm into a rotating drum of the hypergravity field separator corresponding to the overflow port of the grading hydrocyclone group at a certain pressure along a tangential direction through a feeding pump; feeding the raw coal of 1-6 mm into the rotating drum of the hypergravity field separator corresponding to the underflow port of the grading hydrocyclone group at a certain pressure along a tangential direction through a feeding pump so that a material forms descending spiral flow along an inner wall at an upper part of the rotating drum and medium-density and high-density materials descend along outer spiral flow under the action of a centrifugal force to form upward inner spiral flow at an axis of the rotating drum due to a negative pressure, where the low-density material ascends along the inner spiral flow and is discharged through a floating object discharging port, the medium-density and high-density materials are accelerated by a high-speed rotor when descending to the bottom of the rotating drum along the outer spiral flow, the high-density material continues going downward along the inner wall under an action of an additional strong centrifugal force in a hypergravity field and is discharged through a sediment discharging port, and the medium-density material goes upward along the inner spiral flow and is discharged through a floating object discharging port; and dehydrating a product by respectively conveying clean coal and gangue obtained by separation to dehydration treatment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a schematic structural diagram of an underground coal hypergravity field separation system.

[0021] FIG. 2 is a flowchart of an underground coal hypergravity field separation process.

[0022] 1—raw coal conveying pipe, 2—feeding pipe, 3—overflow port, 4—underflow port, 5—first feeding pump, 6—first floating object discharging port, 7—first conveying pump, 8—first sediment discharging port, 9—rotor, 10—second feeding pump, 11—second floating object discharging port, 12—second conveying pump, 13—second sediment discharging port, and 140—third conveying pump.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiment 1

[0023] An underground coal hypergravity field separation system includes a separation unit, a grading unit, and a conveying unit. The separation unit includes a first hypergravity field separator and a second hypergravity field separator. The grading unit includes a grading hydrocyclone group. The conveying unit includes a first feeding pump 5, a second feeding pump 10, a first conveying pump 7, a second conveying pump 12, and a third conveying pump 14.

[0024] A feeding pipe 2 of the grading hydrocyclone group is connected to a raw coal conveying pipe 1. An overflow port 3 of the grading hydrocyclone group is connected to a feeding port of the second feeding pump 10. An underflow port 4 of the grading hydrocyclone group is connected to a feeding port of the first feeding pump 5. A discharging port of the first feeding pump 5 is connected to a feeding pipe of the first hypergravity field separator. A first floating object discharging port 6 of the first hypergravity field separator is connected to a feeding port of the first conveying pump 7. A first sediment discharging port 8 of the first hypergravity field separator is connected to a feeding port of the third conveying pump 14.

[0025] A discharging port of the second feeding pump 10 is connected to a feeding pipe of the second hypergravity field separator. A second floating object discharging port 11 of the second hypergravity field separator is connected to a feeding port of the second conveying pump 12. A second sediment discharging port 13 of the second hypergravity field separator is connected to a feeding port of the third conveying pump 14.

[0026] Both a discharging port of the first conveying pump 7 and a discharging port of the second conveying pump 12 are connected to a clean coal conveying pipe. A discharging port of the third conveying pump 14 is connected to a gangue conveying pipe.

[0027] The hypergravity field separator includes a rotating drum. A rotor is arranged at a bottom end inside the rotating drum. The rotor is used to provide a centrifugal acceleration of 300 times the gravitational acceleration for a material entering the rotating drum. A floating object discharging port is formed in an upper part of the rotating drum. A sediment discharging port is formed in a lower part of the rotating drum.

[0028] A coal separation process based on the underground coal hypergravity field separation system includes the following steps:

[0029] s1, raw coal screening and breaking: raw coal adopts a 6 mm screening standard, an undersized product<6 mm is conveyed to a grading hydrocyclone group, an oversized product≥6 mm is conveyed to a crushing machine and is crushed into particles less than 6 mm, and the particles are returned to a screening process.

[0030] s2, raw coal grading: the raw coal<6 mm is conveyed to the grading hydrocyclone group through a feeding pipe; 1 mm is taken as a grading standard, coarse particles of 1-6 mm are discharged from an underflow port 4 of the grading hydrocyclone group and are conveyed to a first hypergravity field separator; and a fine particle product<1 mm is discharged from an overflow port 3 of the grading hydrocyclone group and is conveyed to a second hypergravity field separator.

[0031] s3: raw coal separation: the raw coal<1 mm is fed into a rotating drum of the second hypergravity field separator at a certain pressure along a tangential direction through a second feeding pump 10, and the raw coal of 1-6 mm is fed into the rotating drum of the first hypergravity field separator at a certain pressure along a tangential direction through a first feeding pump 5, so that a material forms descending spiral flow along an inner wall at an upper part of the rotating drum, and medium-density and high-density materials descend along outer spiral flow under the action of a centrifugal force to form upward inner spiral flow at an axis of the rotating drum due to a negative pressure, where the low-density material ascends along the inner spiral flow and is discharged through a floating object discharging port, the medium-density and high-density materials are accelerated by a high-speed rotor when descending to the bottom of the rotating drum along the outer spiral flow, the high-density material continues going downward along the inner wall under an action of an additional strong centrifugal force in a hypergravity field and is discharged through a sediment discharging port, and the medium-density material goes upward along the inner spiral flow and is discharged through a floating object discharging port.

[0032] s4, product dehydration: clean coal and gangue obtained by separation are respectively conveyed to dehydration treatment.

[0033] The embodiments described above are only description of preferred embodiments of the present disclosure, and do not limit the scope of the present disclosure. Various deformations and improvements made to the technical solution of the present disclosure by those of ordinary skill in the art without departing from the design spirit of the present disclosure shall fall within the protection scope determined by the claims of the present disclosure.