It is an old cyanidation process. Firstly, add cyanide into ore to leach out minerals, then separate the solid and liquid. Add zinc powder or zinc wire into the liquid and the gold and silver will settle as gold mud via chemical reaction. The gold mud containing high gold and silver will be re-smelted to high-pure gold ingot. At present, this process as the cyanidation gold extracting method is widespread used to process flotation concentrated gold ore.
Gold cyanidation-zinc powder replacement gold extracting process flow
Gold Cyanidation- zinc powder replacement gold extracting process mainly include medicating & aeration, agitation leaching, backwashing, zinc powder replacement, gold mud smelting, tailing filter pressing, swage treatment, etc.
1. Agitation leaching- Gold leaching mainly come true in the leaching tank. Under the action of impeller and compression air, the ore pulp containing cyanide was stirred violently. It's good for leaching effect. Generally, leaching tank are used multi series.
2. Backwashing-it is the widely used proces in cyanidation plant. Generally, it use multi single-layer or multi-layer thickener. The backwashing use the next thickener's supernate to dilute last thickener's ore pulp, then the gold grade in liquid will down gradually until reach the standard. Backwashing is the ore pulp diluting & concentration process. Some cyanidation plants use filter press before the washing, then add washing water into filter cake for size mixing and washing. Generally, the first thickener's supernate as pregnant solution will be sent to zinc powder replacement system.
3. Zinc powder replacement-Add the metal reducing agent into cyanidation pregnant solution, the gold and silver will settle as gold mud via chemical reaction. Generally, it include pregnant solution deoxygenation, add zinc powder and lead acetate, filter press getting gold mud, etc.
Main equipment
Cyanidation- zinc powder replacement gold extracting process mainly include thickener, leaching tank, zinc powder feeder, filter press, dosing machine, gold mud smelting equipment, etc.