Gold Refining​

Carbon-in-leach combines leaching with the carbon-in-pulp process, creating a single unit process operation. Usually this method is chosen when native carbon (a high organics load) is present in the gold ore, adsorbing the leached gold and preventing its recovery.

With carbon-in-pulp, the ore is finely ground and the gold is solubilised using a cyanide leach in a series of tanks. Carbon is then added which adsorbs the gold. This method has a high gold recovery percentage. The two gold extraction processes CIL (Carbon in Leach) and CIP (Carbon in Pulp) are quite similar, both using granulated activated carbon to extract the gold from the solution.

Carbon-in-column is mostly used to recover gold and silver from heap leach solutions which are often high in solids content. This method involves the gold cyanide solution flowing through a series of fluidised bed columns in an up-flow configuration. Activated carbon columns are effective for waste gas purification, water treatment, h2s removal from the biogas and gold recovery.