Alluvial gold ore beneficiation technology

Impact gold deposits can be subdivided into bank placer gold mines, river valley placer gold mines, river beach placer gold mines and river bed placer gold mines. Their gold content fluctuates greatly, ranging from tens of milligrams per cubic meter to tens of kilograms per cubic meter. between.

In sedimentary gold deposits, due to being washed during the formation process, useful minerals with a large specific gravity are relatively concentrated. In addition to natural gold, they usually include platinum, cassiterite, magnetite, ilmenite, and chromium. Iron ore, rutile, wolframite, scheelite, rare earth and other minerals. Gangue minerals usually include quartz, garnet, tourmaline, barite, mica, etc.

In the beneficiation stage, alluvial gold mines usually use gravity separation to recover gold, and sometimes a combined process of gravity separation and mercury amalgamation is used. According to the different equipment used, it can be divided into chute selection, jig selection, shaker selection, etc.

1. Chute sorting alluvial gold deposits

As a relatively simple gravity separation equipment, chute separation has the characteristics of large processing capacity, high enrichment ratio, and wide range of separation particle size. The main influencing factors include the width of a 1-meter-long chute or the processing capacity of a collection area of 1 square meter, the inclination of the chute, the slurry concentration, the slurry flow rate, the covering material and shape, the particle size composition of the raw ore, the heavy sand content, the number of flushing times, etc.

2. Jig selection of alluvial gold deposits

Jig sorting has certain requirements on gold particles and content. It is usually used for raw ores with a particle size less than 0.2mm accounting for 10~15% and a gold content of 25~300 mg per cubic meter. It can recover gold particles below 0.2mm. Compared with chute sorting, jig sorting has a higher gold recovery rate.

3. Shaking table selection of alluvial gold deposits

The processing capacity of shaking table sorting is relatively small, but the concentrate obtained has a high enrichment ratio. Sorting can be divided into two types: coarse sand shaking table sorting and slime shaking table sorting. The recovery rate of coarse sand sorting is higher, up to 98%~99%, and the recovery rate of gold ore in slime sorting is only Between 35% and 55%, it is mainly used for selection and selection operations.