This study is focused on the clay deposits at Akerebiata area in Ilorin (north-central Nigeria), southwestern basement complex, Nigeria. The chemical and mineralogical compositions of the clays were investigated with the aim of determining their provenance, weathering history and most suitable use. X-Ray Diffraction (XRD) method was employed for the mineralogical analysis while X-Ray Fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrophotometer (ICPMS) methods were used to for the determination of the bulk elemental composition. XRD analysis revealed kaolinite as the predominant clay mineral (54.2 to 90.9 wt. %) indicating intensive chemical weathering of aluminium-rich source rocks and exhaustive leaching under a warm, humid condition. Other non-clay minerals in the assemblages are quartz, rutile, anatase, microcline and plagioclase. Results of geochemical analysis show predominance of SiO2 (47.14 to 64. 92 wt. %) and Al2O3 (19.47 to 29.39 wt. %) which support the kaolinitic nature of the clay and classify the clay as aluminosilicates. The relatively high mean values of the Chemical Index of Alteration (CIA) and Chemical Index of Weathering (CIW) (87.15 and 90.09) also suggest an intensive chemical weathering in the source area. Other relevant geochemical indices; plot of TiO2, ratios of Th/Co, Th/Cr, Cr/Th and relative proportion of Ni and Cr reveal felsic igneous parent rock. The clays are characterized by light colour, fineness, low-moderate LOI, mineral assemblage and chemical composition that make them favorably compared with standards for refactory, ceramics, pottery and paints.

Geochemical and Mineralogical Studies of Kaolinitic Clays in Parts of Ilorin, Southwestern Basement Rock Area, Nigeria

Debre Tabor kaolin deposit is located around Debre Tabor town in Amhara region of northwestern Ethiopia. The kaolin deposit in the study area needs a detailed study to evaluate the geological, mine...

Mineralogical and geochemical characterisation of kaolin deposit from Debre Tabor area northwestern, Ethiopia

The question is raised as to what extent a study of the clay mineralogy enables the detailed ceramic behaviour of a clay to be predicted. It is indicated that the behaviour of a clay in an industrial process is often controlled by other factors, such as particle size distribution of the clay minerals and firing conditions which must, therefore, also be taken into consideration.

W. F. Cole

Papers

A Note on the Practical Value of Clay Mineralogy in Coarse Ceramics