How to Extract Gold from Rock Gold Ores by Gravity Separation

1.Crushing Stage (Raw Ore Pretreatment)

Rock gold ore with a particle size of ＜600mm is fed into primary crushing equipment (e.g., jaw crusher) and then sent to the secondary crushing stage after preliminary crushing.

After further crushing by secondary crushing equipment (e.g., cone crusher), the particle size of the material is reduced. The crushed material then passes to a vibrating screen for classification. Particles larger than 10 mm are sent to a tertiary cone crusher for fine crushing.

Particles smaller than 10mm enter the grinding stage, while the finely crushed material is returned to the vibrating screen, forming a closed-circuit cycle of “secondary crushing – screening – fine crushing” to ensure the discharge particle size is stably controlled below 10mm.

2.Grinding Stage (Mineral Liberation)

Particles smaller than 10mm are fed into a rod mill and ground into fine-grained slurry, enabling full monomer liberation of gold minerals from gangue minerals and providing optimal feeding conditions for subsequent gravity separation operations.

3.Gravity Separation Stage (Gold Mineral Enrichment)

Rock gold ore requires crushing and grinding before separation to realize monomer liberation of minerals, so that the specific gravity difference between gold and gangue impurities can be manifested. The gravity separation stage is the core link of gold beneficiation for rock gold ores, and the centrifugal concentrator is usually installed after the grinding stage. It mainly processes the fine-grained slurry discharged from the rod mill or ball mill, and performs roughing and enrichment of the liberated natural gold and intergrowths.

Under the action of strong centrifugal force, gold minerals are efficiently enriched to form rough concentrate. The rough concentrate produced by the centrifugal concentrator is directly sent to a shaking table for further separation and purification, and finally high-grade crude gold is obtained.

The tailings enter a hydrocyclone for classification; heavy particles are returned for regrinding and reprocessing to reduce gold loss, thereby significantly improving the total recovery rate of rock gold ores, especially with remarkable recovery effect on fine and micro-fine gold.