Biometallurgy of refractory sulphide ores gold bearing: direct and indirect mechanism discrimination

Biometallurgy is an economically viable and environmentally safer method for the recovery of gold from refractory sulphide ores. Main objective of this experimental work was to study the behaviour of the microorganisms during the attack of different minerals, with the aim to develop a new technology for gold extraction from ores using cyanide as lixiviant. It was shown that bacterial activity enhances the extraction of metals from sulphide complexes. In particular, a high gold recovery has been attained for the biooxidated samples: after cyanidation gold dissolution reached about 90% Au.