The determination of gold in ore samples by inductively coupled plasma optical emission spectrometry (ICP-OES)

Abstract

Fire assay is the most common technique for the determination of precious metals in rock and ore samples, and is generally accurate for the determination of gold. However, with the development of modern laboratory techniques such as Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), alternative methods have become available which offer the advantages of rapid determination of small concentrations of gold in a number of samples for preliminary exploration studies. A multi-parametric linear regression model was used to estimate the observed interferences and using this model, the gold content in ores has been estimated. A simple analytical method for the determination of gold in ore samples using ICP-OES is reported and these results show that this method can be successfully applied when the gold concentration is high (above 0.7ppm) with an error in the range of 9-11% in ore samples. The advantage of thus method over conventionally adopted Fire Assay is small sample size and larger sample throughput.