Leaching of gold and silver from a Kupol composite sample: assessment of the CANMET enhanced leaching process (CELP)

摘要

In an earlier study (Deschenes et al., 2009), gold and silver were shown to be efficiently extracted from samples taken from the Kupol Mine in Russia using lead nitrate in a cyanide leach system. In the current study, a comparison of the technical and economic merits of a new technology called CANMET enhanced leaching process (CELP) was made with the cyanidation/acidification-volatilization-recycling (AVR) process using eight metallurgical variability samples, as well as a large composite sample, which was to represent the initial two years of Kupol mill feed. The composite sample leach feed assayed 33.4 g/t Au and 289 g/t Ag. The metallurgical results from the large composite sample demonstrated that CELP produced very similar gold and slightly higher silver leach extractions compared to the conventional cyanidation/AVR leach conditions at 1/2 the cyanide concentration (1,000 ppm NaCN in CELP vs. 2,000 ppm for cyanidation/AVR leach conditions). It was estimated that the total cost per ton was approximately the same for the two technologies (total cost of CELP with the use of Merrill-Crowe at