Feasibility of Gamma Activation Analysis for Bulk Gold Ore Sorting

Peter Coghill, Channel Tissot, Rhys Palmer

49th Annual Conference of Metallurgists, Vancouver, Canada, August 27-30, 2017.


Due to the low concentrations of gold, direct measurement of gold concentration in ore on-belt has not been seriously considered until now. Pre-concentration ore sorting strategies have largely consisted of particle sorting based on secondary characteristics such as colour, which can be successful in select cases. CSIRO has produced sample measurement results using gamma activation analysis of ~300 g samples with accuracies at approximately 30 ppb. With this encouraging result, a feasibility study was undertaken into gold ore measurement on-belt for the purpose of sorting pods of gold ore. This study included prototype design options with existing industrial Linacs, extensive Monte Carlo modelling of measurement sensitivity and shielding, further sample measurement, a study of the interaction of target measurement accuracy, and sorting efficiency, and a rough estimation of potential economic benefit. The projected accuracies of approximately 0.1-0.15 ppm (1 standard deviation) in 10 seconds for 1 ppm average feed indicate good bulk sorting performance and intriguing economic potential.


CEEC acknowledges and thanks the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), the Metallury and Materials Society (MetSoc) and organising committee for organising the COM 2017 Conference of Metallurgists hosting World Gold and Nickel-Cobalt.

Abstracts can be found at the CIM website (http://web.cim.org/com2017/conference/SessionPapers.cfm#).

Full papers published in the Conference Proceedings will be available on onemine.org, and CEEC directs readers to http://www.onemine.org/ to access and purchase published papers.