JP2020186089A - Granular material conveyance facility - Google Patents

Abstract

To provide an air conveyance facility capable of preventing blocking caused by adhesion of copper concentrate.SOLUTION: An air conveyance facility is constituted by a transport pipe 10 for conveying granular material by an airflow, a cylindrical granular material tank 20 positioned at an upstream side end part of the transport pipe 10, and an air supply device 30 for introducing air for forming the airflow to the granular material tank 20. In the granular material tank 20, at least one air blow part, 23a-23f, for blowing compressed air toward a portion, represented by a corner part at which a side wall and a bottom part are brought into contact with each other, where the granular material easily stays is provided to a side wall of the granular material tank 20.SELECTED DRAWING: Figure 2

Description

The present invention relates to a transport facility for powder or granular material, and more particularly to an air transport facility for transporting dried copper concentrate to a higher position in preparation for charging into a flash smelting furnace.

In the smelting process of dry copper smelting, a copper concentrate having a copper grade of about 30% as a raw material is charged into a flash smelting furnace, and a mat having a copper grade of about 60 to 65% is produced by oxidation and melting. ing. The outokumpu type is often used in this flash smelting furnace, which has a vertical cylindrical reaction shaft that oxidizes the copper concentrate charged from above with oxygen or air, and a mat produced by the oxidation reaction. It is composed of a settler that separates from the slag due to the difference, and an uptake that discharges the exhaust gas generated during the oxidation reaction. As described above, since copper concentrate needs to be charged from the upper part of the reaction shaft, a dry ore storage that temporarily stores powdered copper concentrate dried by the drying furnace in the previous stage above the reaction shaft. Is provided.

As the drying furnace, a rotary dryer composed of a large cylindrical drum rotatably supported is generally used, and the copper concentrate dried in the drying furnace is charged into the drying pit. It is impractical to install a large drying oven at the same high position as the dry mine because the construction cost is high, and the wet concentrate before drying is transported to the high drying oven. Is uneconomical because it requires more energy. Therefore, as disclosed in Patent Document 1, usually, the drying furnace is installed on the ground, and the copper concentrate dried in the drying furnace is carried on the air stream toward the dry ore storage located above the drying furnace. Air transport (pneumatic conveyor) systems are commonly used.

JP-A-2017-160526

The above-mentioned air transport system is a system for transporting powder or granular material on an air flow formed by flowing air in one direction in a transport pipe, and is a transport pipe installed from a transport source to a transport destination along a predetermined route. A powder or granular material tank provided at the upstream end of the transport pipe and charged with the powder or granular material to be transported, and a compressor or blower that supplies air for forming an air flow to the powder or granular material tank. It is mainly composed of air supply means such as. However, when copper concentrate is transported as powder or granular material by the above air transport system, blockage may occur due to adhesion of the copper concentrate in the powder or granular material tank, and the copper concentrate may not be stably transported by air. there were.

The present invention has been made in view of the problems of the above-mentioned conventional air transport equipment for powder or granular material, and is used for adhesion of copper concentrate in the powder or granular material tank located at the upstream end of the transport pipe. It is an object of the present invention to provide an air transport facility capable of preventing the resulting blockage.

The present inventors have taken measures against blockage of copper concentrate in a powder or granular material tank provided at the upstream end of the transport pipe in a facility for air-transporting copper concentrate as an object to be transported to a flash smelting furnace. We have been working on it for many years. As a result, the blockage by the copper concentrate in the powder or granular material tank starts from the region where the fluidity of the copper concentrate decreases or the copper concentrate adheres in the powder or granular material tank. It was thought that the ore was retained and this retained copper concentrate would cause blockage at the inlet of the transport pipe.

Conventionally, when powder or granular material stays in the tank due to adhesion or the like, a method of applying vibration from the outside is generally adopted, but vibration is performed with respect to the powder or granular material tank provided with equipment for air-transporting copper concentrate. The obstruction could not be prevented by the method of giving. Therefore, when compressed air was blown toward the inside of the powder or granular material tank instead of vibration, it was found that blockage due to copper concentrate was less likely to occur, and the present invention was completed.

That is, the air transport facility for powder or granular material according to the present invention includes a transport pipe in which the powder or granular material is transported by an air flow, a cylindrical powder or granular material tank located at the upstream end of the transport pipe, and the like. An air transport facility consisting of an air supply device that introduces air for forming the air flow into the powder or granular material tank, and compresses air toward a portion of the powder or granular material tank where the powder or granular material tends to stay. It is characterized in that at least one air blowing portion for blowing is provided on the side wall of the powder or granular material tank.

According to the present invention, it is possible to prevent the powder or granular material from blocking the inside of the powder or granular material tank located at the upstream end of the transport pipe.

It is a schematic elevation view of the air transport facility of the embodiment of the present invention and the device before and after it. It is a perspective view of the powder / granular material tank which comprises the air transport equipment of embodiment of this invention.

Hereinafter, embodiments of the air transport equipment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the air transport facility according to the embodiment of the present invention is copper having an average particle size of about 5 to 100 μm dried in a rotary dryer 1 using fossil fuel combustion gas or steam to a water content of 1% by mass or less. It is a facility for transporting concentrates, and transports the dried copper concentrates in an air stream toward a dry ore storage 3 located above the reaction shaft 2a of the self-melting furnace 2.

Specifically, the air transport facility according to the embodiment of the present invention has a transport pipe 10 as a flow path for transporting copper concentrate as an object to be transported in an air stream, and an upstream end portion of the transport pipe 10. A vertical cylindrical powder or granular material tank 20 that is located and preferably receives the copper concentrate discharged from the rotary dryer 1 intermittently or continuously via a screw feeder, a rotary feeder, or the like, and the powder or granular material. It is mainly composed of an air supply device 30 such as a compressor or a blower that supplies air to be an air flow to the tank 20, and a cyclone separator 40 provided at a downstream end of the transport pipe 10. The air supplied from the air supply device 30 also plays a role of fluidizing the copper concentrate in the powder or granular material tank 20, and therefore, the air introduction port is provided in the center of the bottom of the powder or granular material tank 20. Has been done.

With the above configuration, the copper concentrate charged into the powder or granular material tank 20 from the rotary dryer 1 is fluidized by the air introduced from the center of the bottom of the powder or granular material tank 20 and formed by the air. Along with the air flow, it is discharged from the powder or granular material tank 20 and introduced into the transport pipe 10, and after being transported in one direction by the air flow in the transport pipe 10, a cyclone separator located at the downstream end thereof. Introduced in 40. In the cyclone separator 40, the copper concentrate is separated from the air flow by air-solid separation using centrifugal force, and the copper concentrate is discharged from the lower part of the cyclone separator 40 and falls into the dry ore storage 3.

On the other hand, since the airflow discharged from the upper part of the cyclone separator 40 contains fine copper concentrate that cannot be separated by centrifugal force, it is further separated by the bag filter 50 in the subsequent stage of the cyclone separator 40. After the fine copper concentrate is collected, it is discharged to the atmosphere. The copper concentrate may be separated from the air flow only by the bag filter 50 without providing the cyclone separator 40.

In the air transport equipment of the embodiment of the present invention, as shown in FIG. 2, the upstream end of the transport pipe 10 penetrates the central portion of the top of the powder or granular material tank 20 and penetrates the powder or granular material tank 20. It extends straight down and opens in the vicinity of the bottom of the powder or granular material tank 20 so as to face the central portion of the bottom. As described above, the opening 11 at the upstream end of the transport pipe 10 opens directly below on the central axis of the powder or granular material tank 20 in the vicinity of the bottom of the powder or granular material tank 20. The copper concentrate in 20 can be discharged from the powder or granular material tank 20 almost evenly in the circumferential direction. The vicinity of the bottom portion means a position separated from the bottom portion by about 0.2 to 1.0 times, preferably about 0.3 times, the inner diameter of the transport pipe 10.

However, in the powder or granular material tank 20, copper concentrate tends to accumulate at the lower corner where the bottom thereof and the cylindrical wall portion contact with each other due to adhesion or the like, and the retained copper concentrate tends to accumulate upstream of the transport pipe 10. The opening 11 at the side end may be blocked. Therefore, in order to prevent clogging due to the retained copper concentrate, the air transport facility according to the embodiment of the present invention is provided with at least one air blowing portion on the side wall 21 of the powder or granular material tank 20. , Compressed air can be preferably intermittently blown to the corners where copper concentrate tends to stay. Thereby, the above-mentioned retained copper concentrate can be effectively removed.

Specifically, as shown in FIG. 2, six air blowouts are made on the side wall 21 of the powder or granular material tank 20 below the inlet 22 into which the copper concentrate dried by the rotary dryer 1 is charged. The portions 23a to 23f are provided at equal intervals in the circumferential direction. These six air blowing portions 23a to 23f are connected to a compressed air supply pipe (not shown), and the above-mentioned intermittent compressed air can be supplied by opening and closing the solenoid valve provided in the supply pipe. The number of air blowing portions is not limited to the above six, and is preferably determined as appropriate in consideration of the size of the powder or granular material tank 20 and the ease of adhesion of copper concentrate.

The timing of the intermittent blowout of compressed air is not particularly limited, but it is generally preferable to blow out the compressed air every 1 to 5 minutes for about 1 to 10 seconds. In this case, compressed air may be blown out from the six air blowing portions 23a to 23f at the same time, but compressed air may be blown out separately for each of 1 to 3 pieces with a time difference. For example, three air blowing portions 23a, 23c, 23e located at intervals of 120 ° in the circumferential direction of the powder or granular material tank 20 and three other air blowing portions 23b, 23d, 23f alternately. It is conceivable to control the opening and closing of the solenoid valve so as to blow out compressed air or blow out compressed air one or two in a predetermined order.

The pressure of the compressed air supplied to the above six air blowing portions 23a to 23f is preferably several kg / cm ² higher than the operating pressure in the powder / granule tank 20 during air transportation, for example, in the factory. Compressed air having a supply pressure of about 5 to 7 kg / cm and ² G, which is used as general air or instrumentation air, can be preferably used. Each air blowing portion is bent so that the tip opening faces directly downward inside the powder or granular material tank 20, whereby compressed air is directed toward the lower corner portion in the powder or granular material tank 20 described above. It can be sprayed vigorously and evenly in the circumferential direction, and the copper concentrate accumulated in the lower corner can be effectively blown off.

The direction of the tip opening of the air blowing portions 23a to 23f is not limited to the case where the compressed air is opened directly below the above as long as the compressed air can be blown toward the region where the copper concentrate stays. , It may be opened horizontally horizontally or diagonally downward. When a plurality of air blowing portions are provided as described above, it is preferable to arrange them so that a unidirectional swirling flow is formed in the powder or granular material tank 20 by the compressed air blown out from them.

The above-mentioned swirling flow is made possible by opening the tip opening so as to blow out compressed air in a clockwise or counterclockwise direction when the powder or granular material tank 20 is viewed from its central axis direction, for example. In this way, by forming a swirling flow that swirls along the wall surface in the powder or granular material tank 20 by the compressed air blown out from the air blowing portion, the entire circumference of the lower corner portion in the powder or granular material tank 20 is formed. Since the swirling flow of the compressed air can be distributed, the adhesion of copper concentrate can be removed more reliably.

As the powder or granular material tank 20 of the air transport equipment for the self-melting furnace 2 of the copper concentrate dried by the rotary dryer 1 as shown in FIG. 1, the one having the structure shown in FIG. 2 was used and provided on the side wall 21. Air was conveyed while intermittently blowing compressed air in the vertical direction downward from the six air blowing portions 23a to 23f. Specifically, by opening and closing the solenoid valves provided in the air supply pipes from these air outlets 23a to 23f, 5 kg / cm ² G of compressed air is blown every 20 seconds for 1 second at the same timing. I made it. As a result, in the open inspection about one month after the start of operation, no copper concentrate was attached to the lower corner of the powder or granular material tank 20.

For comparison, instead of blowing compressed air into the powder or granular material tank 20 from the above air blowing portions 23a to 23f, an air knocker is provided in the powder or granular material tank 20 and the powder or granular material tank 20 is vibrated every 20 seconds. Air transport was performed. As a result, copper concentrate adhered to the lower corner of the tank in the open inspection one month after the start of operation.

1 Rotary dryer 2 Flash smelting furnace 2a Reaction shaft 3 Dry mine 10 Transport pipe 11 Opening 20 Powder or granular material tank 21 Side wall 22 Input port 23a to 23f Air outlet 30 Air supply device 40 Cyclone separator 50 Bag filter

Claims (4)

A transport pipe in which powder or granular material is transported by an air flow, a cylindrical powder or granular material tank located at the upstream end of the transport pipe, and air for introducing air for forming the air flow into the powder or granular material tank. An air transport facility composed of a supply device, in which at least one air blowing portion that blows compressed air toward a portion of the powder or granular material tank where the powder or granular material tends to stay is a side wall of the powder or granular material tank. An air transport facility characterized by being installed in. The air transport facility according to claim 1, wherein the upstream end of the transport pipe opens downward in the center near the bottom of the powder or granular material tank. The air transport facility according to claim 1 or 2, wherein the portion where the powder or granular material easily stays is a corner portion where the side wall and the bottom portion of the powder or granular material tank are in contact with each other. Any one of claims 1 to 3, wherein a plurality of the air blowing portions are provided, and the plurality of air blowing portions are arranged at equal intervals in the circumferential direction of the side wall. Air transport equipment described in.

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