Microwave thermal inertisation of asbestos containing waste and its recycling in traditional ceramics

Asbestos was widely used as a building material prior to the 1970's. It is well known that asbestos is a health hazard and its progressive elimination is a priority for pollution prevention. Asbestos can be transformed to non-hazardous silicate phases by microwave thermal treatment. The aim of this investigation is to describe the microwave inertization process of asbestos containing waste (ACW) and its recycling in porcelain stoneware tiles, porous single-fired wall tiles and ceramic bricks following industrial manufacture procedure. Inertised asbestos powder was added in the percentages of 1, 3, and 5 wt.% to commercially available compositions and then fired following industrial thermal cycles. Water absorption and linear shrinkage of the obtained industrial products do not present significant variations with additions up to 5 wt.% of microwave inertised ACW.