Characteristics and sorting analysis of alluvial gold deposits

Alluvial gold deposits, as an important type of gold deposits, have unique geological characteristics and mineral processing requirements. These gold deposits are notable for their rich mineral assemblages and unique formation processes, while also presenting challenges and opportunities for miners and beneficiators.

1. Main characteristics of alluvial gold deposits

Alluvial gold deposits, also known as sedimentary gold deposits, are gold deposits formed under the action of hydrodynamic forces such as rivers and glaciers. This type of gold deposit is characterized by its rich mineral assemblage and complex formation processes. During the deposition process, various heavy minerals, such as platinum, cassiterite, magnetite, ilmenite, chromite, rutile, wolframite, scheelite, rare earths, etc., accumulate under specific physical and chemical conditions. Together. Natural gold exists in these heavy minerals in different particle sizes and shapes.

In addition, another important characteristic of alluvial gold deposits is their mud content. Depending on the mud content, this type of gold mine can be divided into easy-to-wash, medium-to-wash, difficult-to-wash, and extremely difficult-to-wash types. Fine mud mainly contains non-metallic minerals, such as kaolin, colloidal clay, hydromica, etc., as well as fine mud minerals such as calcite and feldspar. These fine mud minerals have an important impact on the mineral processing process.

2. The selection stage of alluvial gold deposits

In the beneficiation stage, the separation of alluvial gold deposits mainly relies on the combined process of gravity separation and mercury amalgamation. According to the different equipment used, it can be divided into chute selection, jig selection and shaker selection, etc.

Chute sorting: As a relatively simple gravity separation equipment, chute sorting has the characteristics of large processing capacity, high enrichment ratio, and wide range of sorting particle size. The sorting effect is affected by many factors, such as the length, width and inclination of the chute, the concentration and flow rate of the slurry, the shape and size of the covering material, etc.

Jig separation: Jig separation is usually used to process ores with smaller particle sizes, such as ores with a particle size less than 0.2mm. This method has a high gold recovery rate and is usually used to recover gold particles below 0.2 mm. In order to obtain better separation results, certain pre-treatment of raw ore is required, such as crushing and grinding.

Shaking table separation: Shaking table separation is mainly used for beneficiation operations to obtain concentrates with high enrichment ratios. According to the different materials to be processed, shaker separation can be divided into coarse sand shaker separation and slime shaker separation. Coarse sand shaker separation is mainly used to process coarse-grained materials and has a high recovery rate; while slime shaker separation is mainly used to process sludge, and its gold recovery rate is relatively low.