The main methods for gold ore beneficiation are as follows:
Gravity separation method: First, the original gold ore is crushed into small particles, allowing the gold particles to dissociate from the gangue minerals. Then, the crushed ore is fed into the gravity separation equipment, such as a jigger or shaker. High density gold particles precipitate and are collected, while lighter other minerals are washed away. This method is suitable for placer gold, alluvial gold, and some oxidized ores. A jigger is a machine that separates mineral particles of different densities into layers according to their specific gravity, and then uses the action of machinery and water flow to separate and discharge the layered materials. The shaking table mainly uses a transmission mechanism to drive the bed surface for longitudinal reciprocating motion. In the reciprocating process, the ore particles bear the layering effect perpendicular to the bed surface and parallel to the bed surface, allowing materials of different particle sizes to be discharged from the bed surface at intervals and separated.
Flotation method: This is a separation process that utilizes the surface property differences between gold minerals and other minerals. In the flotation process, flotation agents such as collectors and foam agents need to be added. These agents will selectively attach to gold particles to separate them. First, the crushed gold ore is mixed with water, and then flotation agent and foaming agent are added to form foam flotation liquid. The flotation agent will be adsorbed on the surface of gold particles to make them hydrophilic, while the foaming agent will form foam on the liquid surface. Next, air is introduced into the flotation machine to form bubbles attached to gold particles, which are separated from gangue minerals and floated to the liquid surface, and then gold foam is collected for further processing to extract gold.
The above two methods are widely used in gold ore beneficiation, but the specific choice of method depends on the characteristics of the ore and the actual situation of the beneficiation plant. In addition, there are some other methods, such as cyanide gold extraction process, but these methods may be more suitable in certain specific types of ores.
