Mine filling system

1. Tailings concentration and storage system

There are two kinds of tailing thickening schemes, namely vertical sand silo scheme and deep cone thickener scheme. The vertical sand silo is generally composed of the top of the silo, the overflow trough, the bottom of the silo and the slurry pipe fittings in the silo. The bin roof structure includes the bin roof room, sand inlet pipe, hydrocyclone (tailing sand classification), material level meter and pedestrian trestle, etc. The overflow groove is located on the inner wall or outer wall of the bin, and the bottom of the groove has a slope towards the overflow pipe interface. The function of the overflow tank is to reduce the overflow speed and improve the utilization rate of tailings. Silo body is the main component of sand storage, generally made of reinforced concrete or steel directly welded. At first, the structure of hemispherical silo bottom was adopted, which had low sand concentration and was easy to plate. Modern vertical sand silos are generally changed to conical sand discharge structure. After the tailing sand is pumped to the vertical sand silo, natural sedimentation or flocculation sedimentation is adopted to achieve dense dehydration of the tailing sand. The overflow water at the top is recycled through the overflow tank, and the concentrated high-concentration tailing mortar at the bottom is filled with sand by fluidizing slurry.

The deep cone thickener is the key equipment for tailings thickening after the vertical sand silo, which is suitable for the treatment of fine and micro-fine particles. Its biggest feature is that it can obtain a higher mass concentration of underflow, and the production capacity is larger. The free settlement principle of the deep cone thickener is basically the same as that of the vertical sand silo, but the mechanical power structure is added. Its structure is center drive type, the main drive is low speed and high torque turbine reducer, the shell is reinforced concrete viaduct elastic structure or steel structure, and the deep cone reinforced concrete self-waterproof structure is adopted. The upper part of the cone is equipped with a control system, a flocculant adding system and a tailings feed port, which are rotated around the central vertical axis. The lower part of the shaft is provided with a spiral, a harrow frame, a mud scraper with a bottom flow cone, and the bottom of the groove is provided with a paste discharge device.

2. Storage and feeding system for cementitious materials

According to the filling capacity, the material of cementitious material is calculated, and then the cementitious material bin is configured in the filling station. The cementitious material in the bin is fed quantitatively through the screw conveying and metering system on the top of the bin. Cement conveying generally adopts double tube screw conveyor, and measurement adopts spiral electronic scale or punching plate flowmeter. In recent years, the micro-powder weigher with aggregate and conveying has been developed greatly. It has the function of preventing cement silo arch and punching, feed stability, and has been widely used in mine filling system.

3. Filling slurry mixing system

Filling slurry mixing system adopts different mixing technology and equipment according to the different properties of filling slurry. In general, filling slurry mixing is divided into one stage mixing and two stages mixing. The primary mixing is mainly for the two-phase slurry, and the vertical mixing tank is generally used. Two-stage stirring is generally for paste or paste filling. Two-stage mixing is commonly configured with a two-axis blade mixer and a two-axis blade mixer, and a two-axis blade mixer and a high-speed activation mixer.

4. Filling slurry conveying system

Filling slurry transport is divided into artesian transport and pumping, and the artesian transport scheme is adopted as far as possible under the condition that the mine has the artesian transport. It is generally required that the filling line of the mine is less than 6. Specifically, the filling slurry stirred evenly by the mixing system is first reached to the middle part of the underground filling through the filling hole, and then the filling of each stope in the middle part is realized through the horizontal pipeline in the middle part and the drilling between the middle part.

When there is no free flow conveying condition or paste filling is to be used, it is necessary to use pumping, and the plunger pump is used for pumping. The homogenously mixed paste filling slurry at the filling station is pumped to the stope through the plunger pump for filling.

5. Automatic filling control system

The automatic filling control system should have the characteristics of reliable and effective operation, complete functions, simple and flexible operation, easy expansion, convenient maintenance, etc., and carry out comprehensive automatic control and operation monitoring of the filling production process. The automatic control system is required to improve the production capacity of equipment as much as possible, reduce the labor intensity of workers, reduce the accident rate of equipment, reduce production costs, and improve economic benefits under the premise of stabilizing the production process and ensuring the filling index. Therefore, advanced automatic control system should be established in the future filling system to improve work efficiency and ensure filling quality.