From Waste to Wisdom: Sustainable Strategies for Nickel Spent Ore

The heap leaching of low-grade nickel laterite generates large volumes of spent ore, which can pose environmental risks through residual acidity and metal leaching. Indoterra Metallurgy Solutions has evaluated sustainable management strategies, focusing on limestone neutralization and the reuse of treated spent ore for land reclamation and revegetation.

Characterization confirmed residual acidity and base metal contaminants in untreated spent ore. Limestone treatment effectively raised the pH to neutral levels, meeting hazardous waste standards. Toxicological tests (TCLP, LD₅₀) classified the treated material as non-hazardous, while vegetation trials demonstrated plant growth comparable to natural soil, with stable seepage pH (6–7).

These results demonstrate the potential for safe reuse of spent ore in reclamation, offering a sustainable solution to mitigate environmental impacts and support circular economy practices in nickel mining.