Physicochemical Analyses of Selected Clays in Southwestern Nigeria and Their Suitability for Ceramic Production

Abstract

Clay is the most common ceramic material in the world, which is available in every community. Importance of clay made its enquiries prevalent in agricultural, natural and medical sciences, engineering and ceramics. However, inadequate scholarly attentions on physical and chemical examination of clays that are commonly used for pottery in Southwestern Nigeria necessitate this study. This study is on physicochemical analyses of selected clays in Southwestern Nigeria with the aim to observe their potentialities for ceramics production. Direct field survey, laboratory experimentation and studio art practice methodologies were adopted. Ten clay samples were randomly selected and collected at depth of one metre from two actively used clay depots by potters in Ekiti, Ogun, Ondo, Osun and Oyo States. Samples were sundried, pulverised before their chemical components were analysed with Particle Induced X-Ray Emission (PIXE) technique. Water of plasticity, workability, shrinkage and water absorption capacity of the samples were also examined. Findings revealed that oxide concentrations in ten clay samples vary with high concentration of silicon, alumina and iron oxides range from 27.80%-65.24%, 18.75-43.88% and 1.18%-20.38% respectively alongside other minor and trace elements. Moreover, clays with high concentrations of alumina required more water of plasticity. Secondary clays with high alumina have good plasticity but shrink more than samples with low alumina. Water absorption tests also showed that the samples absorbed less than 20% of their volume which make suitable for ceramic production. However, this study observed that selected clays can be further improved to formulate various clay bodies.