Asbestos waste recycling using the microwave technique – Benefits and risks

Abstract

Hazardous waste containing asbestos can be neutralised by temperature destruction using the Microwave Thermal Treatment (MTT). With this method, the temperature and time required for asbestos destruction can be significantly reduced. The literature indicates that a temperature of 1000 °C is adequate for this purpose and can be lowered using fluxes.The article presents a method for identifying trace asbestos contamination in testing a thermal recycling product of asbestos-cement waste using MTT.A low asbestos-fibre content, e.g. at a concentration of less than 0.1%, in any medium, requires the separation and concentration of these fibres before qualitative analysis.The tests used electrostatic separation and instrumental methods to identify asbestos in a sample (OM, SEM–EDS). The presence of chrysotile traces (or poorly processed asbestos fibres) in neutralised asbestos waste was established. The efficiency of asbestos destruction was proved to be insufficient. As such, the MTT technique should be used as a process of inerting or reducing the harmfulness of asbestos waste, rather than recycling it. Lowering the temperature in this process is economically desirable but may run the risk of incompletely destroying the asbestos and leaving behind hard-to-detect traces.