Jig machine

1. What is the sorting process and principle of jigging beneficiation processing?

Jigging beneficiation is carried out in a jig machine. The basic structure of all types of jig machines is similar, and its separation process is carried out in a jigging chamber. The jig chamber has a screen plate in the middle layer, from under the screen plate a vertical alternating water flow is fed periodically, and the ore is fed above the screen plate to form a dense layer of material called the layer, where the water flows through the screen plate and the layer. During the rise of the water flow, the layer is lifted and loosened, and the light minerals rise faster with the water flow, while the heavy minerals rise slower; while when the water flow falls, the light minerals fall slower, while the heavy minerals fall faster. In this way, the heavy minerals tend to the bottom, and the light minerals are located in the upper layer. As the water flow continues to fall, the layer looseness decreases and the movement of coarse particles is hindered. Later the layer becomes more and more compact, only the fine particles can pass through the gap downward movement, called “drilling gap movement”. The downward flow of water stops, the stratification effect also stops, this is a cycle. Then the water flow begins to rise again, starting the second cycle. This cycle continues, and finally the denser particles are concentrated in the bottom layer, and the less dense particles are located in the upper layer, completing the process of stratification by density, as shown in the following Figure. After being discharged separately with a special discharge device, products of different densities can be obtained. The above is the sorting process and principle of jigging beneficiation.

(Black particles in the figure indicate heavy minerals)
a-particle mixing and accumulation before stratification;
b-rising water flow lifts the mineral layer
c-particles settling in water stratification
d-flowing water drops, mineral layer dense, heavy minerals come to the bottom layer

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Jigger machine working principle

Jigging beneficiation is a process in which material is sorted according to density differences, mainly in a vertically elevated, variable speed media flow. The difference in size and shape of the material has an effect on the beneficiation results. The medium used in jigging can be either water or air. When water is used as the sorting medium, it is called hydraulic jigging; when air is used as the sorting medium, it is called wind jigging. At present, the production of hydraulic jigging is the most used, so the content only relates to hydraulic jigging.

The equipment that realizes the jigging process is called a jigger machine. The selected material is fed to the jigger screen, forming a dense layer of material, which is called the bed. While feeding the material, an up and down alternating water flow is fed periodically through the screen plate from the lower part of the jigger, and the material is sorted under the action of the water flow. First, the bed is gradually loosened and suspended under the action of the rising water flow, when the particles in the bed are stratified according to their own characteristics (density, size and shape of the particles) in relative motion to each other. After the end of the upward flow, during the resting period (stop feeding compressed air) and during the downward flow, the bed is gradually compacted and continues to stratify. After all the ore particles have settled on the screen surface, the bed is tight again, and most of the ore particles have lost the possibility of relative movement with each other, and the stratification has almost completely stopped. Only those very fine grains can continue to move down through the gap of the bed (the movement of such fine grains is called drill gap movement), and continue to stratification. After the end of the downward flow, the stratification is temporarily terminated, and the stratification process of one jigging cycle is completed. The stratification process of the material in a jigging cycle is shown in Figure 1. In each cycle, the material can only be subjected to a certain sorting effect, and after several repetitions, the stratification is gradually perfected. Finally, the low density particles are concentrated in the uppermost layer and the high density particles are concentrated in the bottom layer.

The main internal factor for the stratification of the material in the jigging process is the nature of the ore particles themselves, but the objective condition that allows the stratification to occur is the alternating water flow that rises and falls vertically.
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