Cyanide carbon pulp gold extraction process

Raw material preparation,Cyanide stirring leaching,Activated carbon countercurrent adsorption,Gold loaded charcoal desorption,Noble electrowinning,Smelting ingots and activated carbon and other operations.

Concise equipment flow for recovery of gold by the carbon pulp process

Raw material preparation before leaching: The gold-bearing mineral raw material is crushed, ground and graded to obtain a slurry with the required concentration and fineness.When the whole mud is oxidized, this graded overflow can be sent to be leached after concentration. When the flotation method is used to enrich the gold-bearing minerals before leaching, the graded overflow is sent to the flotation operation to produce gold concentrate. After the gold concentrate is ground again to the required fineness, the graded overflow is screened to remove ore sand and wood chips larger than 0.589 mm, and then concentrated and dehydrated to obtain a slurry with a concentration of about 45% and sent to agitated leaching.

Stirred leaching: Stirring cyanide leaching is carried out in 12 aerated mechanical stirring tanks connected in series. The underflow of the thickener first enters the slurry mixing tank, and the slurry is mixed with air and lime milk for several hours in advance to adjust the pH and oxygen content of the slurry, and then enters the cyanide leaching circuit. While stirring and leaching the pulp, lime milk and cyanide still need to be added, and air is blown to maintain the pH and cyanide content of the pulp at the prescribed values. The specific operation is the same as stirred cyanide leaching, the purpose is to obtain the highest possible gold leaching rate.

Activated carbon countercurrent adsorption: The pulp after leaching and leaching into the activated carbon pulp countercurrent adsorption circuit. The adsorption system is generally composed of 4 to 6 activated carbon adsorption tanks, and the countercurrent flow of the slurry and activated carbon is realized through the air lifter and the screen between the tanks. At this time, air can still be blown in to add lime milk and cyanide, but the last 1 to 2 adsorption tanks do not add cyanide to reduce the cyanide content in the depleted pulp. In the initial carbon slurry process, the inter-slot screen mainly used a vibrating screen, and its carbon abrasion amount was relatively large. At present, the inter-slot screen of the carbon slurry process mainly uses a fixed peripheral screen, a bridge screen or an immersion screen. The sieved pulp is returned to the wooden trough, and the activated carbon is sent to the previous trough. The regenerated carbon or new carbon is added to the last tank of the adsorption tank, and the gold-loaded carbon is periodically transferred from the first adsorption tank to the gold-loaded carbon desorption system for gold desorption and activated carbon regeneration. The remaining tailing slurry is then screened (screen opening is 0.701 mm) to recover the lost gold-loaded fine carbon and sent to the tailings treatment process.