Applications of Dissimilatory Iron Reducing Bacteria (DIRB) for recovery of Ni and Co from low-grade lateritic nickel ore

Abstract Dissimilatory Iron Reducing Bacteria (DIRB) in specific has found wide range of application in bio-beneficiation for removal of iron impurities from different ores and in bioremediation for detoxification of heavy metals, hazardous pollutants, etc. Numerous research works have been reported for bio-beneficiation of kaolin, bauxite by IRB. This study aims at studying effect of anaerobic dissimilatory iron (III) reducing bacterial consortium on different phases of iron present in lateritic nickel ore. Such conversion in lateritic nickel ore is helpful in better recovery of sorbed metal values like Ni and Co by subsequent bioleaching or acid leaching. Over the past decade, the global demand-supply chain of nickel is constrained due to depletion of sulphidic nickel ores. However, with anticipated boom in electric vehicles (EVs), the forthcoming decade for battery demand is very bullish for nickel. Hence, there is an urgent need to extract nickel from lateritic nickel ores to meet its high demand. Application of conventional methods for nickel extraction from lateritic ores is challenging from metallurgical and technical viewpoint and requires high capital investments. There is ongoing search for alternative nickel extraction methods from lateritic ores to meet the high nickel demand loom. In India, nickel metal is concentrated in the Chromite overburden (COB) dumps of Sukinda Valley Jajpur, Odisha. The nickel metal is ingrained within the stable goethite matrix (oxidic mineral phase) which requires stringent actions (high energy and/or chemical attack) for its dissociation. 70% Ni and 81% Co was recovered on acid-leaching of DIRB-treated ore whereas only 54% Ni and 57% Co was recovered on acid leaching of untreated COB Hence, pre-treatment of COB with DIRB can enhance the recovery of nickel. Exploitation of competent indigenous microorganisms can thus formulate an eco-friendly approach for nickel extraction. This work discusses the various aspects of microbial application for nickel recovery from lateritic nickel ores.