Investigation of Zarshuran Refractory gold recovery in cyanide process at the presence of Ion Ferric

Zarshuran mine located at 35 km north of Takab city in an area of about 37 square kilometers at a distance of 7 km from Zarshuran village and consists of sulfide minerals such as pyrite, ralgar, overpement, arsenopyrite, stebenite, sphalerite, galen and cinnabar. About 55 to 60% of the gold in this ore is in solid solution inside the crystal lattices of pyrite and arsenopyrite and this has caused the resistance of gold ore in the cyanation process to increase and the percentage of gold recovery in the cyanation process to decrease. Therefore, ferric ion oxidation method was investigated to release gold from sulfide minerals and under optimal conditions, ion ferric concentration of 11 g / l, time 8 hours, temperature 45 ° C, pH equal to 1 and pulp density 25% recovery Gold increased to 72%, while under direct cyanation process without oxidation with ferric ion, the maximum recovery of gold was 41%, which shows that the oxidation process with ion ferric can increase the recovery of gold in the cyanation process by 31%.