An improved process for the treatment of gold-bearing ores, residues and other products

摘要

Gold ores, residues, &c. which may also contain silver are treated by the process of Specification 635,904, and the residue from the cyanide extraction is again subjected to the same roasting and extraction treatment. The temperature of the first roasting should however, be lower, say 700 DEG C., and the second roasting temperature may be higher than 800 DEG C. The first extraction is moreover effected with a strong brine containing alkali and cyanide so that the residue for the second roasting already contains salt, an addition of solid salt being made if necessary. After roasting the material should be cooled quickly to 500 DEG C. to avoid volatization losses.