Challenges in processing nickel laterite ores by flotation

•Until now, flotation has not been successful to recover nickel from laterite ores.•Fine grinding should be used to liberate nickel-containing particles in laterite ores.•Reactor–separator cell with more probability of particle–bubble attachment can help.•Selective flocculation can help to enhance flotation performance of laterite ore.

The challenges in processing nickel laterite ores using flotation process were comprehensively reviewed. Literature shows that flotation has not been successful to recover nickel from laterite ores. Nickel in laterite ores is often finely disseminated in various minerals in very fine size. Therefore, fine grinding can be useful to liberate nickel-containing particles. However, particles resulted from fine grinding are often very fine, and recovery of such particles is low in the conventional flotation cells. It has been suggested that using reactor–separator cells with more probability of particle–bubble attachment can be useful to recover fine particles. Therefore, these types of cells (or similar) should be tested in processing laterite ores. In addition, increasing particle size often results in enhancing the particle–bubble interaction in flotation. Selective flocculation of fine particles could be therefore the key parameter to improve the flotation performance of laterite ores. Flocculation of these type of ores needs to be thoroughly investigated.