Beneficiation of Manganiferous clay from Goa

Abstract

A Sample of low grade Manganiferous clay assaying 33.2% Fe, 8.6% Mn, 13.3% SiO2, 16.8% Al2O3 with traces of P was was received in National Metallurgical Laboratory from M/s. Chowgule & Co., Goa with a view to improving the Fe and Mn contents. Bulk of the sample was composed of clay with hydrated iron oxides, hematite and magnetite as the chief iron bearing minerals. The only manganese minerals identified in the sample was psilomelane which was intimately associated with clay. Scrubbing followed by desliming and hydro-classification tests did not assist in producing concentrates high in Fe and Mn. Tabling, wet magnetic separation and flotation tests also failed to produce concentrates high in Fe and Mn. Reduction roast followed by wet magnetic separation produced a magnetic concentrates assaying 41.3% Fe, 11.2% Mn, 8.5% SiO2 and 10.2% Al2O3 with 91.9% Fe and 91.9% Mn recoveries. The concentrate may be used as a source of Manganese in pig iron after suitable agglomeration, but it may not be economical to adopt the process for this ore.