Abstract
Sometimes gold recovery from its ores represents a challenge. This is due to fine dissemination and interlocking of the gold within the associated sulfide minerals. Many approaches were tried to solve this problem, they included roasting, oxidation in addition to bioprocessing. In the last approach, application of bacteria enhances sulfides bio-oxidation and consequently facilitates their leaching. Therefore, this paper aims at investigating gold biorecovery from Alhura area gold ore, located at Kingdom of Saudi Arabia. Investigated parameters included Feed Size, mm; Dose of bacteria, ml; Retention time, day; Steering speed, rpm; Bacteria nutrient addition rate, K2SO4, kg/t; Bacteria nutrient addition rate, (NH4)(3)PO4, kg/t. Statistical screening of these parameters showed that the most significant ones are: ore feed size, dose of bacteria and K2SO4 nutrition in addition to retention time. However at optimum conditions, (10 ml bacterial dose, 6 days retention time, and 6.5 Kg/t K2SO4 as bacteria nutrient) a gold concentrate containing up to 107 g/t gold from an ore containing 1.14 g/t gold was obtained.