The Process Designing of Gold Extraction from Placers of Passu to Shimshal (Hunza Valley) Gilgit-Baltistan by Mercury Amalgamation and Cyanidation Leached Method

Abstract

Gold wash through panning or washing in the fluvial sediments or sands is done on the river banks in Skardu, Hunza and other places. The method of gold washing is very crude, primitive and most of the gold is washed away back into the river. The current study mainly focused on extraction of placer gold deposits. Pneumatic machines from Passu to Shimshal (Hunza valley) Gilgit-Baltistan. The mercury amalgamation and cyanide leached methods have been used for placer gold deposits extraction from the concentrate obtained from shaking table. The amount of gold recovered from amalgamation method with mercury was 30.9%. The alloyed gold with other metals, gold dust, and fine gold was recovered by chemical process. The reagent consumption, i.e.   1.4 kg/ton of NACN and 6 Kg / ton of CaO were used for extraction of placer gold deposits. The extracted gold is 10.24 g /t and silver 22 g /t and the remaining gold like the amalgamation residue, tailings and middlings are extracted by cyanidation leached method. The extraction of gold by cyanidation process was compared graphically, and study results revealed that extraction of gold using cyanidation leached method was 91.40% and silver 100%, respectively.