A METHOD AND A SYSTEM FOR GOLD EXTRACTION WITH HALOGENS

摘要

The invention relates to a method for the extraction of precious metals, using halogens. It has been found that introducing halogens in the reactor in the form of hypohalites rather than free halogens simplified greatly the recycling of halogens by electrolysis. It increases the rate of addition of the halogens and significantly reduces secondary reactions with base metals such as iron. Operating under acidic conditions, the gold recovery has been found as high with hypochlorite as with elemental chlorine, with an active chlorine to ore ratio reduced by a factor of two to five. Also, a system is disclosed comprising a diaphragm-less electrolytic cell for generating hypohalite; a leaching reactor; and a brine reservoir, said brine reservoir feeding said diaphragm-less electrolytic cell and said leaching reactor.