CeBER Publish in Minerals Journal
Volume 7, Issue 5, 22 May 2017, Article number 85
"Insights into ferric leaching of low grade metal sulfide-containing ores in an unsaturated ore bed using X-ray computed tomography" - Dobson, K.J., Harrison, S.T.L., Lin, Q., Bhreasail, A.N., Fagan-Endres, M.A., Neethling, S.J., Lee, P.D., Cilliers, J.J.
The distribution of the metal-bearing mineral grains within a particulate ore prepared for leaching, and the impact of this spatial heterogeneity on overall extraction efficiency is of key importance to a mining industry that must continuously target ever-reducing grades and more complex ore bodies. If accessibility and recovery of the target minerals is to be improved, a more detailed understanding of the behaviour of the system must be developed. We present an in situ analysis using X-ray computed tomography to quantify the rates of volume reduction of sulfide mineral grains in low grade agglomerated copper bearing ores during a miniature laboratory scale column leaching experiment. The data shows the scale of the heterogeneity in the leaching behaviour, with an overall reduction of sulphide mineral grains of 50%, but that this value masks significant mm3 to cm3 scale variability in reduction. On the scale of individual ore fragments, leaching efficiency ranged from 22% to 99%. We use novel quantitative methods to determine the volume fraction of the sulfide that is accessible to the leachate solution.