Under pressure: Recent successes in high-pressure acid leaching operations for nickel laterite deposits tempered by environmental risks – by Alexandra Lopez-Pacheco (CIM Magazine – August 07, 2023)


The nickel market is expected to undergo a significant shift in the coming years as the global energy transition speeds up. Currently, only about 11 per cent of nickel goes towards the electric vehicle (EV) battery and battery storage markets. The majority of nickel produced—some 65 to 70 per cent—is purchased by the stainless-steel sector. However, in 10 to 20 years, it is estimated that the battery applications market will need some 50 per cent of all nickel produced.

EV batteries cannot use just any nickel, however; battery manufacturers require high-purity nickel sulfate. Almost all Class 1 nickel, which exceeds 99.8 per cent nickel content, comes from magmatic nickel sulfide deposits, which represent only 30 to 40 per cent of known global nickel resources. This has many looking hard at the remaining 60 to 70 per cent: low-grade nickel laterite deposits.

Nickel sulfide deposits, such as those found in Canada, are extracted with conventional and capital-intensive underground mining methods, then processed with flotation. Lateritic nickel deposits, on the other hand, are generally found in surface soil in tropical regions. “The mining of laterites is more of an earth-moving exercise,” said Jan Smit, director of technology innovation at Toronto-based Sherritt International.

The predominant technology used to extract Class 1 nickel and produce high-purity nickel sulfate from nickel laterite deposits is a hydrometallurgical process called high-pressure acid leaching (HPAL), which was developed in the mid-1950s.

For the rest of this article: https://magazine.cim.org/en/environment/under-pressure-en/