Gravity Separation Equipment – Introduction to the Gravity Separation Method

Gravity separation is the core method for placer gold mining, and gravity separation equipment is also the core equipment. Various types of gravity separation equipment, such as jigs and shaking tables, may be used in the washing and beneficiation process. For large-scale placer gold mining, the trapezoidal jig still dominates. Here, we introduce a large-scale gravity separation device – the trapezoidal jig for placer gold mining.

In placer gold mining, gravity separation equipment such as sluices, jigs, and shaking tables are all used. However, considering the recovery rate, beneficiation efficiency, and beneficiation indicators of various equipment, the following issues should be considered first when selecting placer gold mining equipment:

1. The processing capacity of the placer gold mining equipment.

2. The recovery rate of the equipment when beneficiating placer gold.

3. The ease of operation, maintenance, and repair of the equipment.

Firstly, the gold content in placer gold is very low; to achieve profitability, the placer gold mining equipment must have a large processing capacity. Regarding throughput, sluices have the largest throughput, shaking tables the smallest, and jigs are in the middle. Sluices, as roughing equipment for placer gold, have a large sand output and are simple to operate, easy to maintain, and require no power. Shaking tables have extremely small throughput and can only be used for mineral cleaning. Jigs have a moderate throughput and can be used for both roughing and cleaning of placer gold.

Secondly, recovery rate directly affects the normal profitability of a gold concentrator. If a high recovery rate cannot be achieved, even if the gold content of the raw ore is high, ideal economic benefits cannot be obtained. Therefore, concentrators often consider recovery rate as a very important beneficiation indicator. Among the three types of equipment—sluices, shaking tables, and jigs—sluices have the lowest recovery rate, jigs have the highest, and shaking tables are in the middle. Therefore, sluices are often used as roughing equipment for placer gold with very low gold content, jigs can be used for roughing or cleaning, and shaking tables can only be used in conjunction with jigs for the cleaning of heavy sands.

Finally, in terms of equipment operation, maintenance, and repair, the sluice box requires no power, has a simple structure, and requires no maintenance, making it the simplest of the three types of equipment. The operation and maintenance of shaking tables and jigs directly affect the mineral processing indicators; therefore, suitable operators and maintenance personnel are essential when selecting shaking tables and jigs as placer gold washing equipment.

The trapezoidal jig is a side-acting diaphragm jig. Its working face is trapezoidal, divided into four independent processing tanks. The stroke and frequency of each tank can be independently adjusted according to actual conditions, making it very suitable for placer gold washing, especially for the beneficiation of screened placer gold. The beneficiation efficiency and indicators are both satisfactory. The trapezoidal jig is also a gravity separation device in large gold concentrators and gold dredgers.