Cyanide Processing Equipment and Plant Configuration Options. The Jig, placed between the ball mill and classifier, is one of the most valuable and affordable improvements in cyanidation in recent years and was developed by the metallurgical engineering and Mining Equipment Companies. This Mineral Jig has the marked advantage of removing a large portion of the metallic values without excessive dilution, and water or solution is added to the discharge of the jig.
For batch grinding, the artisanal ball mills are ideal for cyanide leaching. The mill leaching process was successfully implemented in Portovelo, Ecuador. About 95% of the gold was leached from a pre concentrate obtained by grinding the ore in Chilean mill and concentrates gold in sluice boxes.
and cyanide solution was added during the stamping process. Any free gold in the pulp was caught by copper amalgam plates. A Dorr screvJ classifier on an incline table at the foot of the stamps received the pulp and removed primary slimes before transferring the muck to a five foot ball mill for fine grinding.
The ball mill, in closed circuit with a classifier, is fed with ore, cyanide, lime, and carbon as charcoal. The classifier overflow is thickened and then agitated. The gold is dissolved by the cyanide solution and then its soluble gold cyanide compound is absorbed by the finely divided charcoal.
A sodium cyanide solution is commonly used to leach gold from ore. There are two types of leaching: Heap leaching: In the open, cyanide solution is sprayed over huge heaps of crushed ore spread atop giant collection pads. The cyanide dissolves the gold from the ore into the solution as it trickles through the heap.
CLS will leach pieces of gold 40 mesh and smaller within 8 to 12 hours. This is a definite advantage over cyanide which can take up to a week to leach 40 mesh gold. This presents a number of trade offs between CLS and cyanide. In most cases, the CLS leaching system can be built much smaller than the cyanide system.