A brief introduction to the types, mining methods and processing of placer gold deposits

Types of gold placer

‌Riverbed gold placer: shallow burial, low mining cost.

‌River valley gold placer: also shallow burial, low mining cost.

‌Alluvial fan gold placer: wide distribution, requires large gold washing plant, high investment, grade above 0.5g/t has investment value.

‌Seashore gold placer: gravity separation effect is not good, chemical leaching is required, high cost, associated high-value minerals can be considered for comprehensive recovery.

Mining methods of gold placer

‌Gold panning: manual method, using water and shallow pan rotation to separate minerals.

‌Washing: using washing box, ripples capture heavy minerals.

‌Dredging: dredgers remove riverbed sediments and process on board.

‌Dry cleaning: used in arid areas, air blows through gravel to separate minerals.

‌Vibrating table: using vibration motion to separate minerals.

‌Spiral concentrator: using centrifugal force to separate minerals.

‌Jig‌: Use jigs to move up and down to separate minerals.

‌Heavy media separation‌: Use dense media to separate minerals based on density.

Placer gold processing process

‌Mining operations‌: Select appropriate mining methods (gold mining ships, engineering machinery, hydraulic machinery).

‌Preliminary treatment‌: Remove large rocks and impurities, including screening and gravity sorting.

‌Washing operations‌: Hydraulic flushing and mechanical action to remove clay and impurities.

‌Gravity separation operations‌: Use the density difference between gold and sand and gravel to separate, commonly using spiral chutes and shaking tables.

‌Selection and purification‌: Improve the grade and recovery rate of gold, use equipment such as shaking tables, and finally cast into gold ingots.

‌Tailings treatment‌: Reduce environmental impact through disposal or reuse, using circulating water systems and tailings dam management.