6- Retrieval and characterization of materials processed in prototype 2

In this action were made all characterisation analyses on the ACW object of SHS tests with Protoype 2. The analyses were carried out by XR powder diffractometry, a technique appropriate to identify minerals in a crystalline mixture, associated with the SEM-EDS technique, that provides information on the habit and on the in-situ composition of the mineral phases (D.M.6/9/94).

 

This phase was important to assess the starting material for future comparison with the same, after combustion with SHS technique. The samples to be analysed by Scanning Electron Microscope (SEM) must be adequately prepared:

  • The representative specimen should be glued to an alumina sample holder  (stub), by carbon tape.
  • The sample are made conductive on the surface by sputtering a very thin gold film.

The SEM analysis provides the imaging of the waste, and coupled with the EDS microanalysis we obtain the chemical composition of about 1 cubic micron of the sample. The two associated informations help the univocal identification if the asbestos.

 

A SEM microphotograph of fibre-cement is reported in Figure 1.

 

 

 

 

 

Figure 1

 

 

A SEM microphotograph of friable asbestos is reported in Figure 2.

 

Figure 2

 

 

We characterised 75 samples with XRD and SEM analysis.

 

 

The action ended by June 2015.