A device for uniformly discharging ore from the center of the bottom of a thickening tank

Abstract

The present invention discloses a device for uniformly discharging ore from the center of the bottom of a thickening tank, which belongs to the field of mining engineering and solves the problem of uneven discharge concentration in traditional large-scale concrete thickening tanks. The present invention includes a central confluence mixer, at least two discharge branch pipes and a discharge main pipe. The central confluence mixer is located in the central column of the thickening tank and below the thickening tank body. The central confluence mixer is funnel-shaped and consists of an inverted truncated cone at the top and a vertical pipe at the bottom. An inner ring annular tooth groove and an outer ring annular tooth groove are arranged at the connection between the truncated cone and the vertical pipe; the discharge branch pipe is connected to the truncated cone; the discharge main pipe is connected to the vertical pipe and connected to the outside of the central column of the thickening tank, and a valve is arranged on the discharge main pipe. The present invention adopts central discharge, and the discharge concentration is uniform and stable, which prolongs the life of the bottom discharge pump. Two rings of annular tooth grooves reduce the flow rate of the discharge branch pipe, reduce the wear at the confluence, and change the direction of the water flow of the discharge branch pipe, reduce the funnel-shaped water plug, and improve the discharge capacity.

Description

Technical Field

[0001] The invention belongs to the field of mining engineering, and in particular relates to a device for uniformly discharging ore from the center of the bottom of a thickening pool. Background Art

[0002] Generally, a large concrete thickening tank is equipped with a bottom center column and a bottom annular gallery. The bottom of the tank body is a gently inclined cone, and there is an annular overflow trough on the upper edge of the inner wall of the tank body to discharge overflow water. The vertical axis located in the center of the tank body is connected to the rake frame mechanism, which consists of rake arms, rake teeth and reinforcement bars. The two radially arranged rake arms are perpendicular to each other in a cross shape. The low-concentration slurry is transported to the center of the thickener by the slurry inlet pipe. After mixing with the reagent, the slurry is divided into two parts, clarified liquid and high-concentration precipitate, by the action of the gravity of the solid particles themselves. The clarified liquid is discharged from the upper annular overflow trough, and the high-concentration precipitate is discharged from the discharge pipes at the bottom of the thickening tank, forming a ring pipe along the bottom annular gallery, and then discharged from one or two total discharge pipes. When the thickening tank is in operation, the ore is generally discharged from the two discharge pipes on the diagonal line, and the two discharge pipes on the other diagonal line are reserved. The concentrated slurry at the bottom of the thickening tank flows with the circular motion of the rake frame and is discharged from the open discharge pipe. The disadvantage of this type of discharge pipe is that the concentration increases sharply when the rake runs to the discharge pipe outlet, and the concentration of the discharge pipe immediately becomes very low when the rake passes over the discharge pipe, and the discharge concentration is very uneven. When a slurry pump is installed at the bottom of the thickening tank, the slurry pump encounters high-concentration slurry, the operating load increases, the motor current increases sharply, and overload occurs; when encountering low-concentration slurry, the motor current drops rapidly. This is very unfavorable for the operation of the slurry pump, resulting in a shortened life of the slurry pump. The slurry valve is frequently opened, has a high failure rate, and is frequently replaced, affecting the normal production of the enterprise. Summary of the invention

[0003] The purpose of the present invention is to provide a device for uniformly discharging ore from the center of the bottom of a thickening tank, so as to solve the problem of uneven ore discharge concentration existing in traditional large concrete thickening tanks.

[0004] The technical solution of the present invention is: a device for uniformly discharging ore from the center of the bottom of a thickening tank, comprising a central confluence mixer, at least two discharge branch pipes and a discharge main pipe, wherein the central confluence mixer is located in the central column of the thickening tank and below the thickening tank body, the central confluence mixer is funnel-shaped, and consists of an inverted truncated cone at the top and a vertical pipe at the bottom, and two layers of annular grooves are arranged at the connection between the truncated cone and the vertical pipe, which are an inner ring groove and an outer ring groove respectively; the discharge branch pipe is connected to the truncated cone; the discharge main pipe is connected to the vertical pipe and connected to the outside of the central column of the thickening tank, and a first valve is arranged on the discharge main pipe.

[0005] As a further improvement of the present invention, four ore discharge branch pipes are provided.

[0006] As a further improvement of the present invention, a buffer tank is provided at the lower end of the vertical pipe, and the buffer tank is located below the connection between the main discharge pipe and the vertical pipe.

[0007] As a further improvement of the present invention, a bottom pipe gallery is provided below the thickening pool body, the bottom pipe gallery is arc-shaped, the main discharge pipe passes through the bottom pipe gallery, and the first valve is located in the bottom pipe gallery.

[0008] As a further improvement of the present invention, the arc angle of the bottom pipe gallery is not greater than 90 degrees.

[0009] As a further improvement of the present invention, the teeth on the inner ring annular tooth grooves are staggered with the teeth on the outer ring annular tooth grooves.

[0010] As a further improvement of the present invention, eight teeth are evenly arranged on the inner ring annular tooth groove and the outer ring annular tooth groove respectively.

[0011] As a further improvement of the present invention, a casing is provided outside the main ore discharge pipe, and the casing is connected to the vertical pipe.

[0012] As a further improvement of the present invention, the discharge branch pipe is arranged inclined.

[0013] As a further improvement of the present invention, the main discharge pipe is arranged at an angle.

[0014] The present invention improves the traditional large-scale concrete thickening tank discharge pipe, adopts the internal discharge mode, each discharge branch pipe discharges ore at the same time, and designs a central confluence mixer inside the central column. The bottom flow slurry is mixed in the central confluence mixer and then discharged by a discharge main pipe, so that the discharge concentration is uniform and stable. The bottom annular corridor does not need to be made into a 360° annular shape, and the bottom annular pipe and the discharge branch pipe valve are omitted, the failure rate is greatly reduced, and the investment is also saved.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The device of the present invention adopts central ore discharge, the discharge concentration is uniform and stable, and the service life of the bottom discharge pump is extended.

[0017] 2. The present invention sets two circles of annular tooth grooves at the bottom of the truncated cone of the central converging mixer. This design reduces the flow velocity of the discharge branch pipe and reduces the wear at the confluence; on the other hand, it changes the direction of the converging water flow of the discharge branch pipe, reduces the "funnel-shaped water plug" and improves the discharge capacity.

[0018] 3. The present invention provides a buffer tank at the lower end of the lower vertical pipe of the central converging mixer, which can increase the mixing force and reduce the wear of the main discharge pipe. If the buffer tank is not designed, the discharge main pipe is directly connected to the lower vertical pipe of the central converging mixer, and an arc-shaped elbow is formed at the connection between the two at the lower end of the discharge pipe, which will greatly accelerate the wear.

[0019] 3. After adopting the present invention, the bottom annular gallery does not need to be made into a 360° annular shape, but only needs to be made into an arc shape not greater than 90 degrees, thereby eliminating the bottom annular pipe and the ore discharge branch pipe valve, greatly reducing the failure rate, reducing the amount of concrete, and saving investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a plan view of the present invention;

[0021] Figure 2 yes Figure 1 AA view in;

[0022] Figure 3 yes Figure 2 DD view in;

[0023] Figure 4 yes Figure 3 BB view in;

[0024] Figure 5 is a top view of the central converging mixing element of the present invention;

[0025] Figure 6 yes Figure 5 The CC view in .

[0026] In the figure: 1-central confluence and mixing; 2-inner ring tooth groove; 3-outer ring tooth groove; 4-vertical pipe; 5-thickening tank body; 6-thickening tank central column; 7-rake frame mechanism; 8-discharge branch pipe; 9-annular overflow trough; 10-slurry inlet pipe; 11-discharge main pipe; 12-first valve; 13-second valve; 14-tee; 15-flushing water pipe; 16-buffer tank; 17-casing; 18-bottom pipe gallery; 19-trunked table. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings.

[0028] Typically, the thickener includes a thickener body 5 , a thickener center column 6 , a rake mechanism 7 and a slurry inlet pipe 10 , and an annular overflow groove 9 is provided on the upper edge of the inner wall of the thickener body 5 .

[0029] The present invention Figure 1-Figure 6As shown, a device for uniformly discharging ore from the center of the bottom of a thickening tank comprises a central confluence mixer 1, at least two discharge branch pipes 8 and a discharge main pipe 11. The central confluence mixer 1 is located in the central column 6 of the thickening tank and below the thickening tank body 5. The central confluence mixer 1 is funnel-shaped and consists of an inverted truncated cone 19 at the top and a vertical pipe 4 at the bottom. Two layers of annular grooves are provided at the connection between the truncated cone 19 and the vertical pipe 4, which are an inner ring groove 2 and an outer ring groove 3 respectively; the discharge branch pipe 8 is connected to the truncated cone 19; the discharge main pipe 11 is connected to the vertical pipe 4 and connected to the outside of the central column 6 of the thickening tank. A first valve 12 is provided on the discharge main pipe 11.

[0030] There are four discharge branch pipes 8.

[0031] A buffer tank 16 is provided at the lower end of the vertical pipe 4, and the buffer tank 16 is located below the connection between the discharge main pipe 11 and the vertical pipe 4. The buffer tank 16 is 30 cm deep.

[0032] A bottom pipe gallery 18 is provided below the thickening pool body 5 . The bottom pipe gallery 18 is arc-shaped. The main discharge pipe 11 passes through the bottom pipe gallery 18 . The first valve 12 is located in the bottom pipe gallery 18 .

[0033] The arc angle of the bottom pipe gallery 18 is not greater than 90 degrees.

[0034] The teeth on the inner ring annular tooth groove 2 are staggered with the teeth on the outer ring annular tooth groove 3. Eight teeth are evenly arranged on the inner ring annular tooth groove 2 and the outer ring annular tooth groove 3 respectively.

[0035] A casing 17 is provided outside the main ore discharge pipe 11 , and the casing 17 is connected to the vertical pipe 4 .

[0036] The discharge branch pipe 8 is arranged downwardly at a certain angle. The discharge main pipe 11 is arranged downwardly at a certain angle.

[0037] A second valve 13 is also provided on the discharge main pipe 11. The first valve 12 and the second valve 13 are connected by a tee 14. The other end of the tee 14 is connected to a flushing water pipe 15. The second valve 13 is located in the bottom pipe gallery 18. When flushing is required, the second valve 13 is closed, and the water in the flushing water pipe 15 enters the discharge main pipe 11 through the first valve 12. After the flushing is completed, the second valve 13 is opened to release the water.

[0038] Example 1: The method for discharging the bottom flow of the tailings thickening pool of a large domestic gold mine concentrator with a diameter of 62 m is as follows:

[0039] 1. The thickening tank body 5 is a concrete structure. The discharge flow rate and the diameter of the discharge pipe are calculated according to the concentration of the bottom flow of the thickening tank. The four discharge branches 8 discharge ore at the same time, and the flow rate is controlled at about 1.0m / s to reduce wear. The diameter of the four discharge branches 8 in this project is selected as DN250.

[0040] 2. Calculate the wall thickness of the discharge branch pipe 8. Generally, a seamless steel pipe is selected, based on the wear within the full service period and taking into account a certain margin.

[0041] The wall thickness of the straight section of steel pipe should be calculated according to the following formula:

[0042] t = P·D / 2Kφσs+C·S

[0043] Where: t-calculated wall thickness of the straight pipe section (mm);

[0044] P-design internal pressure of the pipeline (MPa);

[0045] D-outer diameter of the steel pipe (mm);

[0046] K-design coefficient, 0.72 for general areas outside the pump station and 0.6 for areas inside the pump station;

[0047] σs- minimum yield strength of the pipe (MPa);

[0048] Φ-the weld coefficient of the pipe, which shall be determined according to the relevant provisions of the current national standard "Oil Pipeline Engineering Design Code" GB 50253;

[0049] C-annual wear and corrosion rate (mm / a);

[0050] S-pipeline design service life (a).

[0051] The first item in the formula is the pipe wear caused by the internal pressure of the pipe. Generally, the height of a large thickening tank is 7-8m, and the length of the discharge branch pipe 8 is short. The wear caused by the internal pressure is very small and can be ignored. The wear during the life of the pipe is mainly considered. The annual wear rate is related to the ore properties, flow rate, tailings fineness, and particle size classification. It is generally determined through tests. According to empirical data, it is generally 0.3-0.5mm / year. The service life of this project is 20 years, and considering a certain margin, the wall thickness of the discharge branch pipe 8 is 20mm.

[0052] 3. Design center confluence mixing piece 1. See Figure 4 , Figure 5 , Figure 6 The central confluence mixer 1 is designed to be funnel-shaped, and two annular tooth grooves are set at the bottom of the truncated cone 19 of the central confluence mixer 1. This design reduces the flow rate of the discharge branch pipe 8 and reduces the wear at the confluence; on the other hand, it changes the direction of the confluence water flow of the discharge branch pipe 8, reduces the "funnel-shaped water plug", and improves the discharge capacity. The tooth height on the outer annular tooth groove 3 is lower than the tooth height on the inner annular tooth groove 2. A 30cm buffer groove 16 is designed at the bottom of the discharge pipe.

[0053] 4. The main discharge pipe 11 adopts a casing mode. The main discharge pipe 11 is provided with a casing 17 outside. The casing 17 is directly welded to the vertical pipe 4 at the bottom of the central converging mixing piece 1. Figure 4 . The gap in the middle of the external casing 17 of the main discharge pipe 11 is filled with butter, and both ends are sealed with flexible materials. The casing method is designed mainly because the wall of the main discharge pipe 11 becomes thinner after the external docking flange is worn, and the secondary flange connection can no longer be performed. The casing design is conducive to replacing the external flange and checking the wear of the internal main discharge pipe 11. The diameter of the main discharge pipe 11 is calculated according to the total discharge volume, the total discharge slope is ﹥3%, and the flow rate is 1.2~1.5m / s. The diameter of the main discharge pipe 11 of this project is D377×10, and the diameter of the external casing 17 is D426×10.

[0054] 5. The bottom pipe gallery 18 is made into 90 degrees to meet the installation and maintenance of the main discharge pipe 11. Figure 3 .

[0055] The present invention adopts the method of discharging ore from the inside of the central column, eliminating the traditional bottom annular gallery and annular pipe, and the concentration of the outflow from the bottom flow of the thickening pool is stable. The number of valves is greatly reduced, and the operation reliability is improved.

Claims

1. A device for uniformly discharging ore from the center of the bottom of a thickening tank, characterized in that: The invention comprises a central converging mixing piece (1), at least two ore discharge branch pipes (8) and an ore discharge main pipe (11). The central converging mixing piece (1) is located inside a central column (6) of a thickening tank and below a thickening tank body (5). The central converging mixing piece (1) is funnel-shaped and consists of an inverted truncated cone (19) at the top and a vertical pipe (4) at the bottom. Two layers of annular tooth grooves are provided at the connection between the truncated cone (19) and the vertical pipe (4), namely an inner ring tooth groove (2) and an outer ring tooth groove (3). The ore discharge branch pipe (8) is connected to the truncated cone (19). The ore discharge main pipe (11) is connected to the vertical pipe (4) and connected to the outside of the central column (6) of the thickening tank. A first valve (12) is provided on the ore discharge main pipe (11). The ore discharge main pipe (11) is arranged obliquely.

2. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 1, characterized in that: The ore discharge branch pipes (8) are provided with four.

3. A device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 1 or 2, characterized in that: A buffer groove (16) is provided at the lower end of the vertical pipe (4), and the buffer groove (16) is located below the connection between the ore discharge main pipe (11) and the vertical pipe (4).

4. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 3, characterized in that: A bottom pipe gallery (18) is provided below the thickening pool body (5), the bottom pipe gallery (18) is in an arc shape, the main discharge pipe (11) passes through the bottom pipe gallery (18), and the first valve (12) is located in the bottom pipe gallery (18).

5. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 4, characterized in that: The arc angle of the bottom pipe gallery (18) is not greater than 90 degrees.

6. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 5, characterized in that: The teeth on the inner ring annular tooth groove (2) and the teeth on the outer ring annular tooth groove (3) are arranged in a staggered manner.

7. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 6, characterized in that: Eight teeth are evenly arranged on the inner ring tooth groove (2) and the outer ring tooth groove (3).

8. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 7, characterized in that: The main ore discharge pipe (11) is provided with a casing (17) on the outside, and the casing (17) is connected to the vertical pipe (4).

9. The device for uniformly discharging ore from the center of the bottom of a thickening tank according to claim 8, characterized in that: The ore discharge branch pipe (8) is arranged inclined.

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