Common processing methods for gold

Common gold minerals include native gold, chalcopyrite, and gold sulfides. Different gold minerals have distinct physical and chemical properties, necessitating the use of different processing methods. For example, native gold has a high density and can be extracted using gravity separation or heavy medium separation methods; gold sulfides, due to their sulfide nature, are typically separated using flotation methods.

Common gold ore mineral processing methods primarily include gravity separation, flotation, and cyanidation.

Gravity separation is a method that separates metallic gold in ore based on its physical properties (such as density differences). Gravity separation primarily includes gravity separation, heavy medium separation, and laminar flow separation. Gravity separation uses gravity to separate gold particles from other impurities and is suitable for coarse-grained gold ore. Heavy medium separation achieves separation by having particles float in the medium or sink to the bottom of the medium. Laminar flow separation separates particles based on their settling velocity in a water flow.

Floating separation is a method that uses bubbles to form foam with gold particles in the ore, thereby achieving separation. Flotation processes are primarily divided into direct flotation, counter-current flotation, and mixed flotation. Direct flotation involves direct contact between gold minerals, reagents, and bubbles, causing the gold minerals to float to the surface of the foam. Counter-current flotation adjusts parameters such as pH and reagent dosage in the slurry to alter the surface charge properties of the ore for separation. Mixed flotation combines two or more flotation methods.

The cyanidation method involves using a cyanide solution to react with metallic gold to form soluble gold cyanide, which is then adsorbed onto an adsorbent. The gold cyanide is subsequently desorbed and extracted through electrolysis. The cyanidation method is an important technique for comprehensively extracting metallic gold from fine-grained gold ore.