Petrological, Chemical, and Mineralogical Characterization of Anka (Zamfara State) Manganese Ore

Abstract

Manganese deposit reserves exist in Nigeria, which have potentials as raw materials for industrial applications such as batteries, steel and electrical appliances. The present level of exploitation of Manganese is very low and, in most cases, appropriate processing would be necessary to attain desirable qualities. This paper provides petrological, chemical and mineralogical characterization of manganese ore in Anka area of Zamfara state, Nigeria. A chip of about 1/8 of an inch and about 1 inch by 1 inch was cut from the lumps of Anka (Zamfara state) manganese sample using rock cutter, after which their surfaces were trimmed and the chip was mounted on a grinding machine to make the surface smooth. The samples were mounted on a slide and viewed using Leica Petrological Microscope. 500 g of the ore was weighed using digital weighing balance. The sample was crushed and ground until 80% passing of 250µm is achieved. The ground ore was blended homogenously before the analysis while for the ore microscopy study, true fraction representative of the manganese ore samples were prepared, polished mounts and characterized using Scanning Electron Microscope-energy dispersed X-ray (SEM/EDX). However, X-ray Fluorescence was used to determine the chemical composition while identification of the associate mineral phase was done using X-ray Diffraction. From the petrological analysis carried out on the crude samples reveals the presence of heavy mineral and segregation distribution of the mineral. The XRF results shows 77.81% MnO, 60.26% Mn, 10.9% Fe2O3, 4% Al2O3 while Spessartine (3MnO.Al2O3, 0.830), Silicon oxide (SiO2, 1.122), Quartz (SiO4, 0.728), Pyrolusite (MnO, 1.543), and Almandine (Fe3Al2SiO12, 1.583) were identified as the major phases in the ore.