A method for dedusting a negative pressure balance ore pass

Abstract

The present invention discloses a method for dust removal in a negative pressure balance ore pass. A dust suction drill hole is used to connect the ore pass with the ore discharge openings of each intermediate level. A dust collection hood is arranged above the ore discharge openings of each intermediate level. The dust collection hood and the dust suction drill hole are connected by a dust suction pipe, and a reverse air valve is installed between the dust suction drill hole and the dust suction pipe. The negative pressure generated during the falling process of the ore in the ore pass is used to collect the dust-containing air flow into the dust collection hood above the ore discharge opening, and then re-enter the ore pass through the dust suction pipe, the reverse air valve and the dust suction drill hole, so as to achieve the effect of rapid dust removal at the ore discharge opening. The present invention has the advantages of simple principle and process, strong dust suppression ability, less investment and low energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial dust removal, and in particular relates to a negative pressure balanced chute dust removal method. Background Art

[0002] In mining, the chute is an important part of the ore lifting and transportation process. In general, the ore transportation system of a mine is to transport the ore from the mining site to the mining site chute, and then to the branch chute by a mine car or trackless transportation equipment, and then to the main chute system through transfer. Because there is a height difference of hundreds of meters or even hundreds of meters when unloading the ore from the chute, the loose ore is restricted by the wall of the well, and a piston-like movement occurs during the falling process, causing the air in the chute to be compressed sharply. When passing through the branch chutes in the middle section, a large amount of impact airflow is ejected. The airflow carries a large amount of dust, causing high-concentration dust pollution in the ventilation system. Conventional chute dust removal methods include: setting up a wet dust removal system at the unloading port of the branch chute, constructing a wet dry-wet two-stage dust removal system, and adopting all-wet operations in underground production. Adding a wet or dry dust removal system requires adding equipment, increasing operating costs, and increasing corresponding losses. However, if a full wet operation is used, firstly, the wetting process cannot be controlled, and secondly, it will cause inevitable depletion losses during ore transportation and mining.

[0003] Patent No. CN 202441409 U discloses a chute dust control mechanism, which sets a connecting lane between the ore chute and the waste rock chute, so that the two chutes are mutually pressure relief wells. Although this solution reduces dust overflow to a certain extent, it has a small scope of application. When the ore chute and the waste rock chute are far apart, it will cause the connecting lane project to be too long and the investment to be too large. Patent No. CN 209369860 U discloses a chute blowing and suction dust removal device, which sets an air curtain and a fan at the unloading port to form a closed dust removal space, and reduces dust overflow while ensuring that it does not affect the unloading of the ore. This solution uses an air curtain to block dust suppression, but it needs to add a fan, and the dust airflow impact is large, so the dust suppression effect is not ideal. Patent No. CN109779675 B discloses a composite dust removal and purification system for underground mine chute discharge dust control. It implements dust removal fans through infrared sensing and spray agents, constructs a two-stage dust removal and purification system of spray dust removal and wet dust removal fan purification, and then uses dust-proof sealing curtains to seal and block overflow dust to achieve the effect of reducing dust. However, this place is a high-dust space, and the reliability of the infrared sensor cannot be guaranteed. In addition, the system is complex, which affects the subsequent unloading process and has poor on-site applicability. Patent No. CN205858401 U discloses a deep chute wet and dry two-stage atomization dust removal and purification system, which achieves the purpose of dust control and dust suppression by setting a buffer skylight, setting a connecting lane between the chute and the buffer skylight, and arranging two sets of wet and dry two-stage atomization dust removal and purification systems therein, but its engineering and equipment investment is large, energy consumption is high, and the promotion and application value is low.

[0004] In view of the deficiencies of the above methods, there is an urgent need for a dust removal method for ore passes that has a wide application range, simple process, strong dust suppression ability, low investment, and low energy consumption. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a negative pressure balance dust removal method for ore passes, which adopts the following technical solutions:

[0006] Use a dust suction drill hole to connect the ore pass with the ore discharge ports of each middle section. Install a dust collection hood above the ore discharge ports of each middle section. Connect the dust collection hood and the dust suction drill hole with a dust suction pipe, and install a reverse air valve between the dust suction drill hole and the dust suction pipe. The reverse air valve only allows the air flow to flow from the dust suction pipe side to the dust suction drill hole side and does not allow the dust-containing air flow to flow from the dust suction drill hole side to the dust suction pipe side. During the process of ore dropping in the ore pass, due to the compression of air, the lower part of the ore is the positive pressure section, and the upper part of the ore is the negative pressure section. When the ore reaches above the dust suction drill hole, the dust suction drill hole is in the positive pressure section. Due to the existence of the reverse air valve, it will prevent the dust-containing air flow from overflowing through the dust suction drill hole and the dust suction pipe. When the ore continues to fall to between the branch ore pass and the dust suction drill hole, the dust suction drill hole is in the negative pressure section, and the branch ore pass and the ore discharge port are in the positive pressure section. The dust-containing air flow will overflow upward from the ore discharge port under the action of pressure. At this time, the overflowing dust-containing air flow will be sucked into the dust collection hood above the ore discharge port under the suction of the negative pressure section, and then re-enter the ore pass through the dust suction pipe, reverse air valve, and dust suction drill hole, so as to achieve the effect of rapid dust removal at the ore discharge port.

[0007] Further, the dust suction drill hole is constructed by a down-the-hole drill or a geological drill. The number of dust suction drill holes in each middle section from top to bottom gradually increases. The number of dust suction drill holes in the next middle section is 1.5 - 2 times that of the previous middle section. The specific number of dust suction drill holes in each middle section is determined according to the ore discharge height of the ore pass, the dust content of the ore, the amount of each ore discharge, and whether wet operation is adopted.

[0008] Further, the dust collection hood is installed on the roof of the roadway directly above the ore discharge port by fixed anchor bolts. The dust collection hood is made of steel plate or wooden board, with a wedge-shaped body. The side facing the ore discharge port is processed into an inclined surface, and the inclined surface angle is 30 - 45°. A circular hole for installing the dust suction pipe is reserved at the end of the dust collection hood close to the ore pass, and a circular hole for installing the anchor bolt is reserved at the top of the dust collection hood.

[0009] Furthermore, the material of the dust suction pipe is PVC pipe or steel pipe. One end of the dust suction pipe is connected to the circular hole for installing the dust suction pipe on the dust collection hood, and the other end is connected to the dust suction drill hole through the reverse air valve.

[0010] Preferably, the aperture of the dust suction drill hole is 90 - 120 mm, and the diameter of the dust suction pipe is 88 - 118 mm. The matching principle of the two is to ensure that the diameter of the dust suction pipe is 2 mm smaller than the aperture of the dust suction drill hole for easy installation.

[0011] Preferably, the fixed anchor bolt is a slotted tube bolt or a resin bolt, with a bolt length of 1.8 - 2.2 m, a bolt diameter of 28 - 42 mm, and the bolt tray is a square tray with a size of 100×100 - 150×150 mm.

[0012] Preferably, the aperture of the round hole for installing the dust suction pipe is 90 - 120 mm and is equal to the aperture of the dust suction borehole, and the number thereof is equal to the number of dust suction boreholes in this mid - section.

[0013] Preferably, the aperture of the round hole for installing the anchor bolt is 30 - 50 mm, and the number is 6 - 8, which are evenly distributed on the top of the dust collection hood.

[0014] Beneficial effects

[0015] Compared with the prior art and methods, a negative - pressure balanced shaft dust removal method provided by the present invention has the following beneficial effects:

[0016] (1) The principle and process are simple, and it is easy to master and operate

[0017] Based on the negative - pressure balance principle, a negative - pressure dust collector is formed by using dust suction boreholes, dust suction pipes and a dust collection hood between the shaft and the ore discharge port. The dust generated during the ore sliding process is re - discharged into the shaft through the negative - pressure dust collector by using the negative pressure generated during the ore sliding process, forming a closed air circuit. The method principle and process are simple, which is convenient for on - site mastering and operation.

[0018] (2) Less investment, low energy consumption, and the ore discharge and dust removal do not affect each other

[0019] This method rationally utilizes the negative pressure generated during the ore sliding process for dust removal, only requiring a small amount of pipes, plates and anchor bolts, without adding new ventilation power. Compared with other dust removal methods and systems, it has the characteristics of less investment and low energy consumption. At the same time, the ore discharge and dust removal are carried out synchronously without affecting each other.

[0020] (3) Strong dust suppression ability, effectively improving the working environment at the shaft

[0021] By setting boreholes, pipes and dust - proof covers, a negative - pressure dust collector and a closed air circuit are formed. The dust suppression ability is strong, which can greatly reduce the dust spillage and effectively improve the working environment at the shaft. Description of the drawings

[0022] The following further describes the present invention in detail with reference to the drawings.

[0023] Figure 1 is the front view of a negative - pressure balanced shaft dust removal method provided by the present invention;

[0024] Figure 2 is Figure 1 the B - B sectional view of

[0025] In the figure: 1 - connecting roadway; 2 - dust hood; 3 - fixed bolt; 4 - dust suction borehole; 5 - ore pass; 6 - tray; 7 - branch ore pass; 8 - ore discharge opening; 9 - negative pressure section; 10 - ore; 11 - positive pressure section; 12 - air reversal valve; 13 - dust suction pipe. Specific implementation mode

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope protected by the present invention.

[0027] The main shaft of the ore body development system of a certain lead-zinc mine is a skip shaft, with the wellhead elevation of 986 m, the bottom elevation of 140 m, the net diameter of the shaft of 4.2 m, and concrete support. The skip with a balance weight lifting method is adopted, with a multi-rope drop arrangement, and a 6.3 m 3 multi-rope bottom-discharge skip and a 17.1 t balance weight are configured in the shaft, with wire rope guides, undertaking the ore lifting task of 2000 t / d for the whole mine. The ore produced in each section is poured into the main ore pass through the ore discharge opening of the main ore pass. A crushing chamber is set at the 190 m level underground, equipped with a C100 jaw crusher (power 75 kW) and a ZZG1037 grizzly feeder (power 7.4 kW). After crushing, the ore size is ≤ 300 mm. The belt roadway below the crushing chamber is at the 168 m level, and the skip loading point is at the 160 m level. After the ore is crushed, it is fed to a 1.0 m wide belt conveyor by a GZG120 / 2×2.2 type suspended vibrating ore feeder configured at the bottom of the ore pass below the crusher. A set of weighing and metering device is set below the hopper at the head of the belt. An ore bin is set on the ground. After the ore is lifted to the ground, it is discharged through a curved rail and self-slides to the side ore bin through an inclined chute. The underground ore transportation process is: main ore pass bin → grizzly feeder → jaw crusher → ore pass → vibrating ore feeder → belt → metering device → skip → inclined chute → surface ore bin. Since the dust content in the ore is relatively large, the dust is diffused at the ore discharge opening of the ore pass, and the working conditions are poor. This mine adopts a negative pressure balanced ore pass dust removal method provided by the present invention, which effectively reduces the dust content at the ore discharge opening and improves the underground ventilation quality. The specific implementation technical solution is as follows:

[0028] As Figures 1-2As shown in the figure, a dust suction drill hole 4 is used to connect the ore pass 5 with the ore discharge openings 8 of each level. The dust suction drill hole 4 is constructed by a down-the-hole drill or a geological drill. The aperture of the dust suction drill hole 4 is 90 mm. The number of dust suction drill holes 4 in each level from top to bottom gradually increases. The number of dust suction drill holes 4 in the next lower level is 1.5 - 2 times that in the upper level. The specific number of dust suction drill holes 4 in each level is determined according to the ore discharge height of the ore pass 5, the dust content of the ore, the amount of ore discharged each time, and whether wet operation is adopted.

[0029] A dust collection hood 2 is arranged above the ore discharge opening 8 of each level. The dust collection hood 2 is installed on the roadway roof directly above the ore discharge opening 8 by fixed anchor bolts 3. The dust collection hood 2 is processed from steel plates or wooden boards, and its shape is a wedge. The side facing the ore discharge opening 8 is processed into an inclined plane, and the inclined plane angle is 30 - 45°. A round hole for installing the dust suction pipe is reserved at the end of the dust collection hood close to the ore pass 5. The aperture of the round hole for installing the dust suction pipe is 90 mm, and its number is equal to the number of dust suction drill holes 4 in this level. A round hole for installing the anchor bolt is reserved at the top of the dust collection hood. The aperture of the round hole for installing the anchor bolt is 30 mm, and the number is 6 - 8 and they are evenly distributed on the top of the dust collection hood 2. The fixed anchor bolt 3 is a slotted pipe bolt or a resin bolt. The length of the bolt is 1.8 - 2.2 m, and the rod diameter is 28 mm. The anchor bolt tray is a square tray 6 with a size of 100×100 - 150×150 mm.

[0030] The dust collection hood 2 and the dust suction drill hole 4 are connected by a dust suction pipe 13. The material of the dust suction pipe 13 is a PVC pipe or a steel pipe, and the pipe diameter is 88 mm. One end of the dust suction pipe 13 is connected to the round hole for installing the dust suction pipe 13 on the dust collection hood, and the other end is connected to the dust suction drill hole 4 through a reverse air valve 12. The reverse air valve 12 only allows the air flow to flow from the side of the dust suction pipe 13 to the side of the dust suction drill hole 4 and does not allow the dust-containing air flow to flow from the side of the dust suction drill hole 4 to the side of the dust suction pipe 13.

[0031] During the process of the ore falling in the ore pass 5, the lower part of the ore is in a positive pressure section due to air compression, and the upper part of the ore is in a negative pressure section. When the ore reaches above the dust suction drill hole 4, the dust suction drill hole 4 is in the positive pressure section. Due to the existence of the reverse air valve 12, it will prevent the dust-containing air flow from overflowing through the dust suction drill hole 4 and the dust suction pipe 13. When the ore continues to fall to between the branch ore pass 7 and the dust suction drill hole 4, the dust suction drill hole 4 is in the negative pressure section, and the branch ore pass 7 and the ore discharge opening 8 are in the positive pressure section. The dust-containing air flow will overflow upward from the ore discharge opening 8 through the branch ore pass 7 under the action of pressure. At this time, the overflowing dust-containing air flow will be sucked into the dust collection hood 2 above the ore discharge opening 8 under the suction of the negative pressure section, and then re-enter the ore pass 5 through the dust suction pipe 13, the reverse air valve 12, and the dust suction drill hole 4, thus achieving the effect of rapid dust removal at the ore discharge opening 8.

[0032] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A method for dedusting a negative pressure balance ore pass, characterized in that: The ore pass is connected to the ore discharge openings of each level by means of a dust suction drill hole. A dust collection hood is arranged above the ore discharge opening of each level. The dust collection hood and the dust suction drill hole are connected by a dust suction pipe, and a reverse air valve is installed between the dust suction drill hole and the dust suction pipe. The reverse air valve only allows the air flow to flow from the dust suction pipe side to the dust suction drill hole side and does not allow the dust-containing air flow to flow from the dust suction drill hole side to the dust suction pipe side. During the process of the ore dropping in the ore pass, the lower part of the ore is in a positive pressure section due to the compression of air, and the upper part of the ore is in a negative pressure section. When the ore reaches above the dust suction drill hole, the dust suction drill hole is in the positive pressure section. Due to the existence of the reverse air valve, it will prevent the dust-containing air from overflowing through the dust suction drill hole and the dust suction pipe. When the ore continues to drop to between the branch ore pass and the dust suction drill hole, the dust suction drill hole is in the negative pressure section, and the branch ore pass and the ore discharge opening are in the positive pressure section. The dust-containing air flow will overflow upward from the ore discharge opening through the branch ore pass under the action of pressure. At this time, the overflowing dust-containing air flow will be sucked into the dust collection hood above the ore discharge opening under the suction of the negative pressure section and re-enter the ore pass through the dust suction pipe, the reverse air valve and the dust suction drill hole, thus achieving the effect of rapid dust removal at the ore discharge opening.

2. The method for dedusting a negative pressure balance chute according to claim 1, characterized in that The dust suction drill hole is constructed by a down-the-hole drill or a geological drill. The number of dust suction drill holes in each level from top to bottom gradually increases. The number of dust suction drill holes in the next level is 1.5 - 2 times that of the previous level. The specific number of dust suction drill holes in each level is determined according to the ore discharge height of the ore pass, the dust content of the ore, the amount of ore discharged each time, and whether wet operation is adopted.

3. The method for dedusting a negative pressure balance ore pass according to claim 1, wherein The dust collection hood is installed on the roof of the roadway directly above the ore discharge opening by fixed bolts. The dust collection hood is made of steel plate or wooden board, and its shape is a wedge body. The side facing the ore discharge opening is processed into an inclined plane, and the inclined plane angle is 30 - 45°. A round hole for installing the dust suction pipe is reserved at the end of the dust collection hood close to the ore pass, and a round hole for installing the bolt is reserved at the top of the dust collection hood.

4. A negative pressure balance shaft dust removal method according to claim 1, characterized in that The material of the dust suction pipe is PVC pipe or steel pipe. One end of the dust suction pipe is connected to the round hole for installing the dust suction pipe on the dust collection hood, and the other end is connected to the dust suction drill hole through the reverse air valve.

5. A negative pressure balance shaft dust removal method according to claim 1, characterized in that: The diameter of the dust suction drill hole is 90 - 120 mm, and the diameter of the dust suction pipe is 88 - 118 mm. The matching principle of the two is to ensure that the diameter of the dust suction pipe is 2 mm smaller than the diameter of the dust suction drill hole for easy installation.

6. The method for dedusting a negative pressure balance chute according to claim 3, characterized in that The fixed bolt adopts a slotted pipe bolt or a resin bolt. The bolt length is 1.8 - 2.2 m, and the bolt diameter is 28 - 42 mm. The bolt tray adopts a square tray with a size of 100×100 - 150×150 mm.

7. A negative pressure balance shaft dust removal method according to claim 3, characterized in that The diameter of the round hole for installing the dust suction pipe is 90 - 120 mm and is equal to the diameter of the dust suction drill hole, and the number of such holes is equal to the number of dust suction drill holes in this level.

8. A negative pressure balance shaft dust removal method according to claim 3, characterized in that The diameter of the round hole for installing the bolt is 30 - 50 mm, and the number of such holes is 6 - 8 and they are evenly distributed on the top of the dust collection hood.

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