The case for low-grade sulfide nickel deposits – by Richard (Rick) Mills (A Head Of The Herd – October 4, 2022)


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.

Nickel laterite deposits were first discovered in 1864 by French civil engineer Jules Garnier in New Caledonia — commercial production started in 1875. New Caledonia’s laterites were the world’s largest source of nickel until Sudbury Ontario’s sulfide deposits started production in 1905 and totally dominated global production.

However, existing sulfide mines are becoming depleted, and nickel miners are having to go back to the lower quality, but more expensive to process, as well as more polluting, nickel laterites such as found in the Philippines, Indonesia and New Caledonia.

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