Nickel deposits come in two forms: sulfide or laterite. About 60% of the world’s known nickel resources are laterites, which tend to be in the southern hemisphere. The remaining 40% are sulfide deposits. The main benefit of sulfide ores is that they can be concentrated using the fairly simple flotation technique.
There is no such technique for nickel laterites. The rock must be completely molten or dissolved to enable nickel extraction. As a result, laterite projects require large economies of scale at higher capital costs to be viable. They are also generally much higher cash-cost producers than sulfide operations.