Bacterial oxidation of an auriferous arsenical concentrateBacterial oxidation of an auriferous arsenical concentrate Πλήρης Δημοσίευση σε Συνέδριο Conference Full Paper 2015-11-131994enIn this study the bacterial oxidation of an extremely refractory auriferous arsenical pyrite concentrate from Olympias, Greece, is examined. A solution exchange system comprised of two 5 L capacity air-stirred pachuca reactors was used in order to enhance oxidation kinetics and reduce retention times when operating at high pulp densities and finally achieve high percentages of oxidation for both sulphide phases. Inoculated with bacteria and bacterial ferric liquor tests were performed in order to determine the effect of the variation of the particle size of the concentrate on the percentage of oxidation for both mineral phases for a pulp density range varying between 5 and 30% w/v and to examine the importance of the bacterial ferric solution as leaching agent.http://creativecommons.org/licenses/by-nc-nd/4.0/351-359Hydrometallurgy ’94Hydrometallurgy ’94 Conference Proceedings Komnitsas Konstantinos Κομνιτσας Κωνσταντινος Pooley F. D. Springer Netherlands Auriferous arsenical pyrite concentrate Solution exchange system Arsenopyrite oxidation