CIL gold leaching process mainly include : Impurity removal , condense before leaching , leaching and adsorption , desorption and electrowinning , hydrometallurgy , regeneration of activated carbon, Tailings treatment , used water treatement, etc .
1.Impurity removal: remove the impurity like the grass root&sawdust before cyanide leaching, avoid those impuritiesadsorbing the gold from ore slurry, and avoid them blocking the carbon sieve.
2. Condensebefore leaching: usually in order to reach a suitable leaching ore density, the slurry should be condensed through the thickener before leaching, the ore slurry density could influence the leaching time and the floating of activated carbon.
3. Leaching and adsorption: pump slurry ore into the double-impellers leaching tanks, there are always 6-8 tanks working togheter; add cyanide solution into first one or two leaching tanks, add activated carbon into the rest gold leaching tanks; activated carbon adsorb gold and become the loaded gold carbon, the loaded gold carbon lift into the lifting screen by air lifter, meanwhite the lifting screen separate activated carbon and slurry ore.
4. Desorption and electrowinning: the desorption of activated carbon and electrowinning the liquid gold are donein a compactedsystem, with high temperature and high pressure; after desorption and electrowinning, gold loaded activated carbon will release gold mud and become barren carbon. We call this desorption&eletrolytic system.
5. Smelting: after acide washing and decontamination, gold mud will be smelted into gold bars.
6. Regeneration ofactivated carbon: the activated carbon after desorption, needs to do acide washing to remove the carbonate left inside the carbon porosity, this will enable carbon to recycled use for several times, and save cost.