A process involving pre-concentration, drum agglomeration and column leach was evaluated for nickel laterite ores from Western Australia. The result showed that pre-concentration by selective comminution followed by size classification has a potential to upgrade nickel laterites and to improve the leaching performance of agglomerated particles. Selective comminution of siliceous goethitic, saprolitic, and goethitic nickel laterites was investigated to upgrade nickel into the fine fraction using stirred milling. The breakage rates of minerals, grinding time, and the weight ratio of soft and hard minerals in the feed play an important role in selective grinding and nickel upgrade. When the grinding time and breakage rates were optimized, the weight ratio of the soft and hard minerals in the feed determine the potential for selective grinding and the nickel grade in the soft mineral determines the limit of nickel upgrade.
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