METHOD OF PURIFYING GOLD

摘要

The present invention is a method of increasing the gold content of metallic gold comprising the step of exposing the metallic gold composition to a leach liquor. The leach liquor is selected to dissolve the impurities from the metallic gold composition without dissolving a significant amount of the gold metal. Preferably, the leach liquor is a solution having a highly acidic dissociation constant, a high oxidative potential and a high tendency to complex cations. The present method preferably includes the steps of roasting the gold in an oxidizing atmosphere or atomization before leaching. The metallic gold composition may be repeatedly roasted and leached until the desired gold purity is obtained.