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 regrinding ???flotation - oxidizing, gravity concentration - amalgamation, flotation ???regrinding - cyanide, high intensity magnetic separation - regrinding ???cyanide, the 4 crafts to process gold tailings. Xinhai Co. Ltd. provided the gold tailings recovery service for Henan Lingbao Jinyuan Company. Xinhai chooses double loop flotation process to remove mines vicious circulation problem. The suitable reagents selected helped improve the recovery rate, and owner obtained 4000g gold from 120, 000 tons gold tailings. After extracting gold, Xinhai recovered sodium cyanide in pulp to eliminate the toxicity of pulp.
The next step is tailings dry stacking to recover water from pulp. Xinhai dewatering system includes hydrocyclone, deep cone thickener and muti-frequency dewatering screen. The efficiency of this system is up to 85%.
After the 2 steps, mine owners not only obtain the gold, but also reduce the danger of tailing bar.