Assessment of the Mineralogical and Elemental Compositions of the Clays of Otukpo, Benue State, Nigeria as Potential Raw Materials for Manufacturing of Bricks, Refractories and Geopolymers

Abstract

More than ever, the present age has witnessed a global rise in the cost of building and construction materials 
especially cement and unprecedented high-rising emission of greenhouse gases like CO2. In the present 
century of fast-growing global building and construction industries, it has become highly essential to find 
alternatives to cement mortar and concrete, through green chemistry research initiatives. Therefore, the 
mineralogical characterization and elemental assessment of Otukpo clays was performed by a combination 
of different instrumental analysis. This study utilized X-ray fluorescence (XRF), flame atomic absorption 
spectroscopy for the compositions of the oxides of the elements of the clay, XRD for mineralogical analysis 
and SEM for crystal structural analysis. The results showed that the clay contains the elements: Boron 
aluminide-Bal (95.719%) > Fe (2.468%) > K (0.973%) > Ti (0.588%) > Ca (0.169) and other trace elements 
including: Zr = 0.021%; V = 0.015%; Cr = 0.013%; Sr = 0.011%; Bi = 0.010; Rb = 0.008% and Nb = 
0.004%. XRD showed that the clay contains the minerals: Al2O3 = (197368 ppm); SiO2 = (97200 ppm); 
Fe2O3 = (63921ppm); CaO = (28040 ppm); MgO = (20150 ppm); TiO2 = (11211 ppm); K2O = 
(2008.30ppm); Na2O (674ppm). These results reveal a high content of Al2O3 and SiO2, which are suitable 
requirements for production of cement and other geopolymers. And therefore, the clays could be explored 
and utilized to meet the housing deficit of the nation, and also as a rich source of minerals and metals that 
can be extracted, for foreign exchange earnings.