Comparison of different extraction methods to determine gold in geological samples

Abstract

Different petro-chemically varied lithological samples were collected from the Chitradurga schist belt, Karnataka, to identify auriferous zones. The efficiencies of gold estimation at very low levels by different extraction methods were compared. The extraction methods were fire-assay (FA), cyanide leach, and methyl isobutyl ketone (MIBK) solvent extraction. The rock samples include banded iron formations (silicate, oxides, carbonate and sulphide facies), ferruginous cherts, massive milky white quartz veins and highly sheared fractured translucent dark grey to bluish grey quartz veins. After separation and pre-concentration of gold, MIBK solvent extraction procedures have been studied using flame atomic absorption spectrophotometer (F-AAS).