Nickel laterite concentration through a non-conventional method with surface sulfidization

Abstract

Nickel ores are found mainly as sulfides and laterites in oxidized ores, such as iron oxides, which are usually “Ni-bearing”. This investigation determined the physical-chemical conditions necessary to increase the tenor and recovery in lateritic deposits, with the implementation of a new technology that allows the increase of the tenor (a process called “up-grading”). The froth flotation is proposed as a concentrating process to increase the Nickel content in the lateritic deposits. By means of sulfidization and direct flotation, specific hydrophobicity of the mineral is achieved, substantially improving the nickel concentrations in the process, with recoveries close to 86%, which, compared with conventional direct and inverse floats without effecting this activation with Na2S, results in recoveries of 70% and 16%, respectively. The reverse flotation also increases the Nickel content with an approximate recovery of 70%; however, the froth flotation, with activation Na2S is still better.