CYANIDE RECOVERY AT CERRO VANGUARDIA

摘要

After a desperate first six months, when the gold plant solid/liquid separation circuits were almost inoperable, the metallurgical team at Cerro Vanguardia, with considerable assistance from Unifield Engineering, has developed a workable and sustainable solution for the continued operation of Cyanisorb~(TM). The problems experienced at the Cerro Vanguardia cyanide recovery installation were unique and were not encountered at other Cyanisorb~(TM) operations. Since conversion to treating tailings solution, the Cyanisorb~(TM) plant is recovering over half the cyanide requirement for the gold plant. It is making a positive contribution to working costs of approximately dollar0.75 per tonne, even allowing for the necessity of limited cyanide destruction. This is relative to the hypothetical scenario where the total gold plant tailings would have to be subjected to cyanide destruction by a combination of hydrogen peroxide and natural attenuation (estimated to be the cheapest option of those considered). However, unresolved issues are the relatively poor cyanide recovery in Cyanisorb?despite operating the acidification section at below pH4 and the continued high presence of sodium carbonate in the acidification section feed solution.