Mineralogy, Chemical Composition and Ceramic Properties of Clay Deposits in Southern Thailand

Abstract

The mineralogical, chemical composition and ceramic properties of clay deposits from southern Thailand were studied to assess their potential for use in the ceramics industry. Samples were collected from 11 localities where clay mining and processing plants are active in southern Thailand. X-ray powder diffraction patterns with sample treatments by glycolation and heat treatment were used to analyze the clay and non-clay minerals and the X-ray fluorescence method was used for elemental analysis. The data collected from these techniques showed that the clay minerals were kaolinite, halloysite and illite and the non-clay minerals consisted of quartz, microcline, gibbsite and anatase. The results from the chemical analysis of the clay samples showed that the most important components were SiO2 (46.75–63.17%) and Al2O3 (20.01–37.03%), since they have a conclusive influence on the refractoriness and strength of the final product. Firing characteristics from 800 to 1,300 °C were used to determine firing shrinkage, color, bulk density, modulus of rupture, water absorption and phase transformation. Ranong clays had the necessary properties for the manufacturing of ceramic products. However, for clays from Nakhon Si Thammarat, Surat Thani and Songkhla, it will be necessary to add other components to enhance their workability.