Asbestos treatment technologies

The use of asbestos was banned because of the carcinogenic properties of its fibres, but asbestos-containing wastes are still present in great amounts. They are currently landfilled or encapsulated with resins, but these approaches led to the release of fibres in the environment. Hence, the destruction of asbestos fibres is now regarded as a preferable option. This study aims at reviewing the currently available technologies for the destruction of asbestos fibres, considering thermal, chemical and mechanochemical processes. The considered thermal treatments include both standard vitrification and thermal treatments with controlled recrystallization. Advantages and applications of the addition of other inorganic materials are described, and the use of microwaves and oxyhydrogen as heat carrier are discussed in full details. The best practices for chemical treatments based on strong acidic or basic solutions are reported, as well as the use of fluorine. This study also investigates the reaction of asbestos with reducing agents in the self-propagating high-temperature syntheses and the use of supercritical water in a hydrothermal treatment. Mechanochemical processes such as high-energy milling are also reviewed. A comparison is given in terms of energy costs, consumption of chemicals, emissions and final use of obtained byproducts.