Shaker beneficiation is a combination of mechanical asymmetrical reciprocating motion and thin layer bevel water flow on a sloping bed surface, so that the ore particles are loose, layered and zoned on the bed surface, so that the minerals are made according to different densities. The process of sorting.

The shaker has a sloping bed surface with a plurality of parallel strips or grooves in the longitudinal direction of the bed. One end of the shaker is equipped with a transmission mechanism, which drives the bed surface to make asymmetrical reciprocating rocking in the longitudinal direction. The bed surface is inclined at 1.5 degrees to 5 degrees to the tailing side, and the slurry and the flushing water are given from the side of the bed surface. people. In this way, the ore particles are subjected to the longitudinally oscillating bed surface and the lateral water flow on the bed surface, so that the ore particles are layered according to density and particle size and move along different directions of the bed surface, presenting a regular "fan-shaped" zoning, and respectively It is discharged from the concentrate end of the bed surface and different areas on the tailings side, and is separately divided into concentrate, medium mine and tailings.

(1) The stratification of the different density of the ore particles between the bed strips plays an important role in the sorting of the shaker.

Figure 3-7 shows the stratification of the ore particles between the beds. It can be seen from Fig. 3-7 that the ore particles form a multi-layer distribution in the groove between the bed strips: the uppermost layer is coarse and light ore, followed by fine and light, again heavy and thick, and the lowermost layer is large density. And small granular particles. On the one hand, this stratification is due to the dynamic action of the inclined water flow and the separation of the bed surface reciprocating shaking action. The separation stratification is an important feature of the shaker separation. On the other hand, eddy currents are formed as the water flows through the grooves of the bed, as shown in Figure 3-8. Causes the pulsation of the water flow, loosening the ore particles and stratifying according to the sedimentation speed. In addition, eddy currents are also advantageous for washing out small density ore particles in a dense mineral deposit. Therefore, the hydraulic grading of the feeding of the shaker in advance according to the equal ratio is advantageous for sorting. In summary, the stratification of the ore particles between the bed bars is mainly due to the combined result of sedimentation stratification and separation stratification.

The stratification of the ore particles between the beds

(2) The movement of different density ore particles on the bed surface and the separation of the ore particles between the bed strips also move in different directions along the bed. At the beginning, the ore particles are relatively static on the bed surface. To make the ore particles move relative to each other in the bed, it is only possible when the inertial force of the ore particles is greater than the friction between the ore particles and the bed surface.

Ma≥G0 f (3-5)

In the middle

M—the quality of the ore particles;

A—the inertial acceleration of the ore particles;

Go—the weight of the ore in the water;

f—The coefficient of friction between the ore and the bed surface.

The minimum inertia acceleration necessary for the ore particles to be relatively stationary to just move can be called critical acceleration, ie

Since G0 =mgo (go is the gravitational acceleration of the ore in the medium), the critical acceleration of the ore in the medium is:

Akp=g0f (3-7)

Therefore, the critical acceleration depends not only on the coefficient of friction but also on the density of the ore particles.

It can be seen that the relative movement of the different density of the ore particles to the bed surface is different from the beginning, and the speed is also different.

Figure 3-9 is a motion diagram of the ore particles on the bed surface. As shown in Figure 3-9, there is two ore particles of the same volume and different density, which will move in two different directions; set 711 > V2, under the action of water flow, the transverse direction of large density ore The moving speed is S1, the small density is S2, and S1

It can be seen from the above that under the combined action of inertial force, friction force, separation and lateral water flow, the different sizes of the ore particles have different speeds in the longitudinal direction on the one hand, and flushing by the water flow in the lateral direction on the other hand. Not the same, the final result forms a fan-shaped distribution as shown in Figure 3-10, so that the mineral particles are sorted by density.

Movement diagram of ore particles on the bed surface

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