THE INVESTIGATION OF GOLD AND SILVER RECOVERY FROM AKOLUK (ORDU -TURKEY) ORE

6th International Scientific Conference - SGEM2006, www.sgem.org, SGEM2006 Conference Proceedings/ ISBN: 954-918181-2, June 12-16, 2006, Vol. 1, 251- 258 pp

ABSTRACT

In this study, the amenability of Akoluk (Ordu -Turkey) ore to the extraction of gold and silver by cyanide leaching was investigated. Mineralogical analysis of the ore has revealed the presence of native gold and a variety of minerals including barite, zinkenite, stibnite, orpiment, realgar, cinnober, pyrite and sphalerite. No silver was detectable under microscope suggesting that it could be present as occluded in minerals such as fahlerz, antimonite and zinkenite. Gold particles as 1-88 μm in size were observed to be associated with quartz and sulfide minerals. Gold and silver content of representative sample was determined to be 15 g/ton and 220 g/ton, respectively.
The leach tests have shown that the extraction of gold and silver was consistently low i.e. ≤47% and ≤19.2% respectively over a leaching period of 24 h. Even fine grinding (i.e. -38 μm) did not improve the recovery of gold and silver. The consumption of cyanide was determined to be 4.4-6.4 kg NaCN per ton of the ore with its tendency to decrease as the particle size decreased. These findings highlighted the refractory characteristic of the ore, which appears to warrant pretreatment to overcome its refractoriness prior to cyanide leaching