subject: Oxidizing Roasting Method Of Gold Ore [print this page] Gold roasting method is first applied to the beneficiation of refractory gold ores, usually air or oxygen-enriched roasting at a temperature of 600-900 , sulfide sulfur and arsenic, respectively, decompose and burn into O2 and As2O3, so that the carbonaceous oxidation loss of activity, resulting in a porous calcine gold exposure, cyanide permeable into the calcine and leach contained gold. Produce flue gas O2 and As2O3 by recycling utilization. Oxidizing roasting method has been widely used in dealing with intractable complex sulfide ores and concentrates. The roasting method is especially suitable for both sulfide wrapped in gold, and carbonaceous material robbed of gold refractory ores. (Conventional oxidizing roasting of refractory gold ores France)
1987-1992 North American 4 roaster put into operation. Big Spring Mine roaster handling ore 1100t average ore grade is: 1.6% total sulfur, organic carbon 0.3%, 0.24% arsenic, gold 5.3g / t, the final gold recovery rate of more than 91%. Oxidizing roasting of sulphide ore, more than 8% sulfur in the calcined material, spontaneous combustion, so the processing of refractory gold concentrates for roasting oxidation general concentrates the sulfur content of sulfur oxidation process is put in more than 15%thermal reaction, and therefore do not need heating. However, the calcined ore sulfur is only 1% -3%, unable to self-heating must also add a lot of fuel and such ore roasting unit cost is relatively high. (Refractory gold ore the curing roasting method)
The roasting method is very sensitive to operating parameters and feed ingredients likely to cause burning or owed to burn, which will make the calcine gold cyanide leaching rate is not high. Burnt the reasons for the gold loss is the formation of gold particles wrapped in a roasting phase impermeable objects, As2O3 and Fe2O3 reaction of the lack of impermeable ferric arsenate (FeAsO4), it will cover the surface of the gold, hinder gold dissolved in cyanide solution, generated at the same time the hematite physical parcels and pore sintering closed, resulting in the "second Refractory. Owed to burn is not sufficient sulfide decomposition. Has been developed to address these issues, the circulating fluidized bed calcinations and two oxygen roasting process and equipment. For the purposes of the original ore roasting, the roasting process, circulating oxygen-rich air roasting process and stages of boiling, roasting process. These two new technologies to the formation of a new trend of Refractory Gold Ore roasting, roasting all ores by roasting concentrates to. For the purposes of the original ore roasting, the roasting process, circulating oxygen-rich air roasting process and stages of boiling, roasting process.(Flash Roasting of Refractory Gold Ore)
