Geochemical and Mineralogical Characteristics of Sakpe Ironstone around Jima, Northern Bida Basin, Nigeria

Abstract

The geochemistry and mineralogy of the Sakpe Ironstone were studied around Jima, Northern Bida Basin, Nigeria. Ten representative samples of the ironstone submitted for geochemical and mineralogical studies using X-ray fluorescence spectrometry, transmitted light microscopy and X-ray diffraction techniques. The result of the chemical analysis revealed that the ironstone contain an average of 58.9wt% Fe, 28.94wt% Si and 12.91 % Al. The average concentrations of P, K, Ca, Ti, Mn, Mg, and Na are 0.03wt%, 0.002wt%, 0.071wt%, 0.177wt%, 0.184wt%, 0.027wt% and 0.008wt%respectively. The results show that the ironstones are of high grade, having iron content > 54 % set by the Natural Resources Canada. Similarly, the low Mg (MgO wt %) content of between 0.01 and 0.051and absence of sulphur in the ironstonesshows that the sediments were not deposited in a full marine environment; perhaps they were deposited in a non-marine to shallow marine environment. Mineralogical analysis showed that the ironstones contain goethite and hematite as the major phases with kaolinite and quartz as impurities. The petrologic analysis showed that the structure of the iron bearing minerals are in form of river lines and plates which are the characteristics of goethite and hematite. The result of the XRD and the petrologic analysis both confirm that the studied Sakpe ironstone is predominantly goethite and hematite iron bearing minerals from which a high concentration of iron