Abstract: In order to study the effects of bacteria in malachite leaching of low acidity (pH=2), the contrasts of the malachite leaching with acid, sterile and bacteria were made to investigate the influences of the bacteria, the initial concentration of Fe²⁺ on leaching, and the necessity of acid adjusting. Then the scanning electron microscope was applied to observe the changes of the mineral surface forms and the adsorption characteristics of bacteria before and after leaching, analyzing the difference of the surface composition of the leaching residue through quantitative analysis with spectral scanning. It was obtained that with the initial concentrations of bacteria and Fe²⁺ of 1×108/mL and 4.5 g/L separately, the bacteria own an optimum promotion on the leaching of malachite.

Key words: Malachite, Bacteria, Acid adjusting, CO₂, Fe²⁺