Process for treating ore having recoverable gold values and including arsenic-, carbon- and sulfur-containing components by roasting in an oxygen-enriched gaseous atmosphere

摘要

Recovery of a precious metal value from refractory carbonaceous and sulfidic ores, concentrates or tailings which also include arsenic- containing components is improved by roasting the ore or ore concentrate in an oxygen-enriched gaseous atmosphere having an initial oxygen content from about 25 percent (by volume) to about 65 percent (by volume) while maintaining a reaction temperature of less than about 600 degrees Celsius during the roasting and while maintaining a minimum amount of iron to react with arsenic and for forming ferricarsenate; thereafter recovering a thus-roasted ore as calcine, whereby the calcine is amenable to recovery of precious metal values in it; gold ores are preferred candidate ores.