Nickel Bioleaching at Elevated pH: Research and Application

摘要

Biohydrometallurgy has broad prospective application in the treatment of low-grade nickel sulfide ore. However, quite a number of nickel sulfide deposits are associated with basic gangue minerals such as those containing olivine or serpentine. The high basic gangue minerals will lead to a higher acid consumption and make it difficult to bioleach at pH below 2.5. It is crucial to improve processes and adapt bacteria to this kind of ore. This paper reviews the experimental studies and industrial applications for bioleaching of high acid consumption nickel sulfide ores. It is suggested that bioleaching at elevated pH will have similar leaching rates compared with pH below 2.5, meanwhile the cost will be decreased remarkably due to a lower acid consumption and fewer dissolved impurity ions.