Raw kaolinitic-illitic clays for the production of refractory ceramics

Abstract

The study makes a unique effort to characterize all the necessary characteristics of refractory clays and products fired at temperatures between 1100 and 1300 °C on a laboratory level. For 19 composite samples from the recently opened reservoir, thorough instrumental and ceramic-technological data are presented. The potential for using Serbian raw refractory clays from the recently discovered deposit is investigated. The composites had a variety of qualities and varied in composition, but they were majorly composed of kaolinite and illite and had a significant share of fluxes. The samples had high quantities of clay minerals and organic matter, which is seen as the most intense mass loss in the 400–600 °C range. Low-duty and high-duty refractories could be distinguished by their refractoriness over 1581 °C. This parameter was mostly influenced by the content of alumina and kaolinite within the materials. Hydraulically-pressed ceramic tiles, following the firing stage, showed water absorption was between 9.02–1.42 % and a modulus of rupture of 16.5 – 53.6 MPa. Color is determined by spectrophotometer and correlated to the composition of the initial clay and fired products. For the lining of ceramic and glass furnaces, the majority of these clays can be used as natural refractory materials. Some of the samples' organic content has a detrimental effect on the fast-firing procedure, since the occurrence of the entrapped air (bloating).