DEVELOPMENT OF HEAT-TREATED LIGHTWEIGHT TERRA-COTTA BODIES CONTAININGLOW-GRADE TALC

Additives not only improves the required properties in final product l ike dimensional accuracy, water absorption, mechanical strength, etc. but also contributes to energy conservation (being used as fluxes), in sulating properties, act as filler and extender. Keeping this in view, a study on the influence of a additive (low grade talc) on red clay w as carried out to develop heat treated light weight bodies by measurin g dry and fired properties, when added progressively. The influence of low grade talc additions to plastic red clay is progressively more si gnificant with increase in firing temperatures from 950-degrees to 110 0-degrees-C. The impurities present in talc mainly free lime behaves a s an inert material at low temperatures (< 950-degrees-C) and then as an opening agent at higher temperatures up to 1050-degrees-C and thus reducing the fired shrinkage to appreciable extent.