RF thermal plasma treatment of waste glass and its reutilization in composite materials

Fluorescent lamps glass powders are sieved in two particle size ranges and are subjected to thermal plasma in-flight treatment by injection into the discharge of a Tekna PL-35 plasma torch and reaction chamber as part of a source operated at 3MHz with a maximum power of 25kW, with Ar as plasma and carrier gas and N2 as sheath gas. The sieved powders and the plasma treated ones have been characterized by powder XRD and particle size analysis in order to verify if the plasma treatment can induce modification in the mineralogical and physical characteristics. The spherical shape of the particles have been analyzed by scanning electron microscopy. Moreover, this technique has allowed to verify if the plasma treatment can induce modification of the (qualitative) chemical composition of the powder. Results for various operating conditions and injection probe positions are presented. The spherical powders have been then introduced in thermoplastic polymer (polypropylene) in place of glass spheres usually used, and the results are compared to each others. The samples are characterized by mechanical tests (flexural strength) and microstructural analysis (SEM) in order to verify the differences in materials properties obtainable by mean of conventional and plasma assisted processes.