Column Bioleaching of Nickel from Sulfidic Samples with Different Nickel and Magnesium Content

Abstract Nickel is a valuable metal that is becoming more prevalent in the industry. Column bioleaching was used in this study to extract nickel from magnesium-bearing sulfide minerals. Two different sulfidic samples with different nickel and magnesium content were utilized to investigate the performance of column bioleaching. It was discovered that mesophilic cultures’ adaptation is delayed by increasing magnesium contents. Bioleaching outperformed leaching in terms of recovery by 80% compared to 50% in sample 1 and 70% compared to 40% in sample 2. Jarosite is precipitated in samples with a high magnesium content due to the high pH and oxidation level, which lowers bioleaching effectiveness. The pretreatment method using acid washing before the start of bioleaching treatment can reduce the amount of magnesium in samples, which increases the Ni recovery in both samples. SEM analysis was performed on each bioleaching residue. The result showed that high amounts of magnesium in the second sample could be a factor in the precipitation of jarosite. Finally, it can be concluded that the pretreatment method is a feasible Bio-heap operation. RESEARCH HIGHLIGHTS Column bioleaching of nickel was tested by mix mesophile culture in two different samples. Bacteria were found to be less adaptable to magnesium-rich minerals. More than 95% of nickel was extracted from both samples. Acid washing was identified as the best pretreatment method for each sample. Graphical abstract