The beneficiation methods for rock gold ore

Rock gold ore, as one of the primary forms of gold resources, is characterized by its large reserves and wide distribution. Compared to placer gold deposits, the mining and beneficiation of rock gold ore are more complex. This article primarily introduces the beneficiation methods for rock gold ore and the required equipment.

I. Crushing

The extracted raw ore must undergo two-stage crushing. The primary crushing stage generally employs a jaw crusher, which, with its powerful crushing force, can efficiently break hard rock gold ore. The secondary crushing of rock gold ore is typically accomplished using a cone crusher. The cone crusher utilizes the principle of laminated crushing, resulting in a more uniform particle size.

II. Grinding

Grinding is employed to fully liberate the rock gold ore, making it a critical step influencing the beneficiation outcome. An overflow-type ball mill is used for wet grinding, leveraging the impact and grinding action of steel balls to reduce the material to a fineness of around 200 mesh. To precisely control the grinding fineness, the ball mill is often operated in a closed circuit with a spiral classifier, ensuring complete liberation of the rock gold ore.

III. Gravity Separation

Gravity separation is the core method for rock gold ore beneficiation. Commonly used gravity separation equipment includes jiggers, vibrating chutes, and centrifugal concentrators.

The jigger generates pulsating water flow, causing the bed layer to first loosen and then compact. Heavier gold particles penetrate the gaps in the bed layer and settle at the bottom, thereby achieving rough concentration and enrichment of the rock gold ore.

The vibrating chute is primarily used to recover tailings from the jigger. By combining mechanical vibration with gravity sedimentation, it significantly enhances the recovery rate of fine-grained gold from the tailings.

The centrifugal concentrator utilizes a high-intensity centrifugal force field to intensify the separation process, offering unique advantages for recovering ultra-fine gold particles from the tailings of the vibrating chute.

IV. Flotation (Oxidized Rock Gold Ore)

For certain types of oxidized rock gold ore, flotation serves as an important supplementary method. A mechanical agitation flotation machine is used to adjust the floatability of minerals, enabling gold particles to rise with air bubbles and achieve efficient separation from gangue.

The beneficiation methods for rock gold ore can be summarized as involving crushing, grinding, gravity separation, flotation, and other processes.