Characterization of Kaolin Deposits in Okpella and Environs, Southern Nigeria

Abstract

Kaolin is one of the most important industrial minerals whose application is dependent on its structure and chemical composition. This study makes an attempt to explore and determine the origin of kaolin deposits within and around Okpella, as well as to investigate the mineralogical and chemical compositions using the X-ray diffraction (XRD) and X-ray fluorescence (XRF) method. These were carried out with the intention of determining the most suitable applications for the clay mineral. It was observed that major phases in the clay samples from the three different deposits are kaolinite, microcline, illite/mica, plagioclase/albite and quartz. These phases were observed in varied percentages. Samples from Ajego 2 show a marked absence of kaolinite but contain high concentration of plagioclase feldspar and quartz which permit its usage in the production of glass and iron industries. Further, the samples from Ajego 1 contain by far the highest concentration of kaolinite, while the samples from Anegha consist of kaolinite, a mixed layer of illite/mica, plagioclase, alkali feldspars, and albite which is necessary for producing mullite fibers in ceramic matrix at a temperature of around 1400°C and it is suitable in pigment production. The XRF result for Ajego2 and Anegha samples has Silica composition of 51.847 wt%, 32.540 wt% and 37.295 wt% respectively and an alumina content of 14.962 wt%, 29.834 wt% and 20.227 wt% respectively. The trace amount of some of the oxides such as K 2 O, TiO 2 , Fe 2 O 3 and SnO 2 can help in the beneficiation process.