Gold mine tailings, the treasure place of recovery gold

As for the beneficiation process today, gold tailings contain a certain number of gold residues after the gold processing. It is wasteful to stack these tailings without reusing. According to incomplete statistics, emissions of state and local gold mine tailings are more than 20,000,000 tons each year, while the gold content is up to 1g/t, so the total content of gold is very considerable.

In 1976, several large tailings of South Africa began to tailings disposal, and has been profitable until now; In a Canadian gold tailings disposal project, a period of processing 50,000,000 tons of tailings, the average grade of tailings is 0.52 grams / tons, and finally, the average recovery rate was as high as 60%. Due to its high recovery value, treatment and recovery of gold tailings are ahead of other minerals both in technology and promotion.Gold mine tailings reprocessing needs to go through two steps: first of all, we need to extract gold from the tailings pulp; then,tailings dry stacking, it means the solid-liquid separation of tailings pulp.

According to the occurrence characteristics of gold tailings, we can adopt the following four processes to treat them: 

1. Regrinding–flotation–oxidizing

2. Gravity concentration–amalgamation

3. Flotation–regrinding–cyanidation

4. High-intensity magnetic separation–regrinding–cyanidation

Xinhai Co., Ltd. provided gold tailings recovery services for Henan Lingbao Jinyuan Company, selecting a double-loop flotation process to solve the vicious circulation problem in the plant. The suitable reagents used helped improve the recovery rate, enabling the owner to obtain 4,000g of gold from 120,000 tons of gold tailings. 

After extracting the gold, Xinhai recovered sodium cyanide from the pulp to eliminate its toxicity. The next step was tailings dry stacking to recover water from the pulp. Xinhai's dewatering system includes a hydrocyclone, deep-cone thickener, and multi-frequency dewatering screen, achieving an efficiency of up to 85%. After these two steps, the mine owners not only recovered gold but also reduced the environmental risks of the tailings dam.