Thermal decomposition of asbestos and recycling in traditional ceramics

Given the known carcinogenic effects, its wide occupational exposures and widespread use in the past, asbestos is considered a general health hazard and a priority treatment for pollution prevention. In this context, asbestos can be entirely transformed to a mixture of non hazardous silicate phases throughout a thermal treatment at 1000-1250 degrees C and to a silicate glass at T>1250 degrees C. These products may be recycled for the production of traditional ceramics. In this paper we describe the recycle of thermally treated asbestos containing materials as a raw material for glass ceramics and traditional ceramics. A significant improvement of the technological properties of porcelainised stoneware, obtained by high sintering of unglazed ceramic bodies, is accomplished by the addition of 5 wt% of an asbestos-based glass ceramic. (C) 2000 Elsevier Science Ltd. All rights reserved.