Published online by Cambridge University Press: 12 February 2019
In this contribution, a new raw material, Uşak clay (Usc), was investigated in order to assess its potential for the ceramic industry by comparing it with a world reference ceramic material, a Ukrainian clay (Ukc). Mineralogical characterization (X-ray diffraction [XRD], scanning electron microscopy [SEM] and Fourier-transform infrared [FTIR] spectroscopy), quantitative chemical analysis (X-ray fluorescence [XRF]) and the thermal properties of Ukc and Usc samples were investigated. Additionally, Atterberg limits, particle-size distribution and cation exchange capacity of both samples were determined. Various technological properties of Ukc and Usc were determined in the temperature range 800–1430°C. The bending and compressive strengths, total linear shrinkage, colour, water absorption and unit-volume mass values were measured. The findings from these analyses show that kaolinite-dominated Ukc and quartz-dominated Usc samples differ from each other not only mineralogically, but also in terms of their chemical, physical and technological properties. The firing colour of Usc was determined as 84% white, and so this can be considered as a light firing clay. In addition, due to its low plasticity, Usc may be utilized to reduce both the plasticity of the ceramic materials and the viscosity in slip-casting applied ceramics. Furthermore, the melting temperature of 1300°C suggests that Usc cannot be classified as refractory. However, this property does suggest an economic value for Usc in terms of developing technological characteristics at lower firing temperatures.
This paper was originally presented during the session: ‘CZ-01 – Clays for ceramics’ of the International Clay Conference 2017.
Guest Associate Editor: Michele Dondi