Beneficiation studies on a low grade Nickeliferous ore from Assam

Abstract

A low grade Nickeliferous ore sample , assaying 0.48% Ni, 8.94% Fe, 37.0% SiO2, 2.00% Al2O3,0.04% CaO, 32.83% MgO,0.05% Co and 0.146% S, from Moreh area of Assam was received from the Geological Survey of India, Assam Circle, for beneficiation studies. The samples consisted chiefly of a green serpentinous matrix with a small amount of opaque mineral grains(chiefly magnetite) finely disseminated throughout the matrix. The liberation of opaque mineral grains was fairly good below 270, mesh. The pressure of any nickel mineral could not be conclusively established by Petrological studies. Straight wet magnetic separation at -100 mesh and -200 mesh sizes as well as tabling at 065 mesh followed by high intensity magnetic separation of the table concentrate did not yielded satisfactory results. The nickel content was almost uniformly distributed in all the products indicating that the ore was not amenable to concentration by normal ore-dressing methods. The possibilities of recovering nickel by extractive metallurgical techniques are being investigated separately in the National Metallurgical Laboratory.