Research on some major factors affecting Ni and Sc extractions in the sulphuric acid stirred leaching of limonite ore
Abstract
Nickel and scandium were extracted from limonite ore under atmospheric pressure leaching conditions. The following variables were examined to understand their effects on nickel and scandium extraction: sulphuric acid concentration, leaching temperature, leaching time, liquid-to-solid ratio and particle size. After 4 h of leaching, ~70% Ni and ~80% Sc were obtained under the following conditions 4M H2SO4, 80°C, solid to liquid ratio = 1/10 (gr/ml) and laterite particles P80 = 63 µm at stirring speed = 500 rpm. The results indicated that although limonite ore contains low grade of Ni and Sc, under optimal leaching conditions, Ni and Sc could be obtained with high efficiency. Using sulfuric acid as a reagent is economical and it also limits the dissolution of impurity components into the solution.
