∗ Bioleaching is the extraction of metals from their ores through the use of living organisms.
∗ It is the Conversion of insoluble metal sulfides into water-soluble metal sulfates.
∗ Nowadays bioleaching occupies an increasingly important place among the available mining technologies
Benefits of bioleaching
∗ Simple and inexpensive process. Substantially lower capex and opex than in traditional smelting and refining processes
∗ No sulfur dioxide emissions as in smelters
∗ No need for high pressure or temperature
∗ Leaching residues less active than in physico-chemical processes
∗ Ideal for low grade sulfide ores – lower cut-off rate possible
∗ Bioleaching can extract metals from ores that are too poor for other technologies. It can be used to partially replace the extensive crushing and grinding that translates to prohibitive cost and energy consumption in a conventional process
Disadvantages of bioleaching
∗ The bacterial leaching process is very slow compared to smelting.
∗ Toxic chemicals are sometimes produced in the process