a b s t r a c tThis study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption. Operational parameters such as the nature of the oxidant (Fe 3+ , O 2 ), the initial ferric iron concentration (0-10 g/L) and the temperature (21-50°C) were identified to have an important influence on the degree of copper solubilisation. At optimal process conditions, copper extraction above 90% was achieved in both leaching systems, with a leaching duration of 1 day. The bacterial leaching system slightly outperformed the chemical one but the positive effect of regeneration of Fe 3+ was limited. It appears that the Fe 2+ bio-oxidation is not sufficiently optimised. Best results in terms of copper solubilisation kinetics were obtained for the abiotic test at 50°C and for the biotic test at 35°C. Moreover, the study showed that in same operating conditions, a lower acid consumption was recorded for the biotic test than for the abiotic test.
a b s t r a c tThe influence of grinding chemistry on the flotation behaviour of sulphides minerals has been widely studied. However, its influence on partially oxidised sulphide ores is not well documented. Various oxidation events can affect a sulphide ore, either during in situ weathering of an ore body or during the different extraction and processing stages (mining operations, stockpiling, crushing, milling and flotation). In this study, a hypogene copper sulphide ore was artificially oxidised to various lengths of time by percolating a small quantity of acidic ferric sulphate solution inoculated with a mixed bacterial culture through packed columns. For each time interval a series of grinding-flotation tests using different grinding media alloys was completed. The grinding and flotation chemistry were compared and linked to the flotation behaviour of the ore samples.The results reveal that as oxidation progressed the copper metallurgy deteriorated. However, the deleterious effects of oxidation could be partially overcome through the application of the right grinding chemistry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.