KINETIC STUDY OF CEMENT-ASBESTOS THERMAL DECOMPOSITION PROCESS UNDER ISOTHERMAL CONDITIONS

Asbestos is a general name applied to a group of silicate minerals which naturally occur in fibrous form. It is a natural mineral widely used in the past, especially in the construction industry. Despite its good performance properties, it is currently known that asbestos has carcinogenic properties. The problem of storing asbestos wastes is significant worldwide. This especially applies to countries where the production and use of asbestos products is prohibited by law. One of the possible methods of proceeding and solving the above problem is a thermal treatment, which results in thermal decomposition of dangerous asbestos fibers. The kinetic study of the thermal decomposition process carried out for cement-asbestos has been investigated by ex-situ thermal treatment. Obtained results allow for kinetic interpretation of this thermal transformation. The kinetic analysis of the isothermal data using an Avrami model yields values for the overall reaction order. The apparent activation energy of the thermal decomposition process for tested cement-asbestos sample is about 160 kJ/mol.