Influence of Firing Temperature on the Physical, Thermal and Microstructural Properties of Kankara Kaolin Clay: A Preliminary Investigation.

Muazu Abubakar,Ashwini Kumar,Norhayati Ahmad,Catalin I Pruncu,Dipen Kumar Rajak,Luciano Lamberti,Ayyankalai Muthuraja

doi:10.3390/ma13081872

Abstract

In this study, natural deposits of Kankara kaolin clay were collected and investigated in order to determine physical, microstructural, thermal, and firing properties and assess clay’s suitability as starting material for various ceramic applications. Chemical analysis of the clay was performed using XRF. Mineralogical analysis and thermal analysis of the clay were conducted using XRD and thermogravimetric thermal analysis (TGA)/differential thermal analysis (DTA), respectively. In order to assess its ceramic behavior, the clay was fired at 900–1200 °C. Maturation characteristics of fired ceramics were assessed by measuring bulk density, apparent porosity, and shrinkage. It was found that main oxides in the clay are alumina, silica, and potassium oxide, while other oxides are present in trace quantities. Kaolinite, quartz, and illite are the phases found from the XRD results, while mullite ceramic phase formed at firing temperature above 1100 °C. Maturation tests showed that ceramic properties such as bulk density and shrinkage increase with temperature, while apparent porosity decreases with temperature. The results presented in this study prove that the clay is an appropriate material for producing traditional ceramics.

Highlights

Natural clay and clay minerals are important raw materials for ceramic industries
The phases in the raw clay and the sintered clay at 1200 ◦ C were detected by means of X-ray diffraction diffraction (XRD)
XRD patterns were accessed with Cu K radiation (λ = 0.1504 Å) in 5◦ = 2θ = 50◦ in steps 0.05◦

Summary

Introduction

Natural clay and clay minerals are important raw materials for ceramic industries. Clay and its minerals have been widely used as a raw material for building and construction industries, such as tiles and bricks [1]. The properties of clay that are of interest to ceramic industries are chemical composition, phases present, thermal properties, refractoriness, and strength after firing [2]. These properties are vital for the optimization of a clay deposit in ceramic industries. Materials 2020, 13, 1872 attention should be paid to investigating the ceramic properties of clay deposits such as Kankara clay. Nigeria has largest deposits of clay in the African continent; they can be found almost in every state [3]

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Results

Conclusion