AbstractAn Italian University research laboratory has developed a system able to treat waste-glass powders in order to obtain a spheroidized powder so as to lower the final material cost because the glass particle is less expensive than the virgin PP. They are looking for license agreement and industrial development.
DetailsThe laboratory has treated waste-glass powders within a laboratory scale RF thermal plasma source, described as follows: 25kW Lepel Corporation (USA) R.F. power supply working at 3MHz equipped with built-in protection systems against high temperatures; a control console Tekna Plasma Systems (Sherbrooke, Quebec, Canada) RF-CS-30 with gas flowmeters for operation with Ar, Ar/H2 or any other auxiliary gas (Air, N2, O2); Tekna Plasma Systems ICPT Model PL-35 with ceramic confinement tube for operation up to 30kW; Tekna Plasma Systems powder feeder PF-400; Tekna Plasma Systems external cooling system; downstream plasma reactor system is designed for fly-ash vitrification purposes as well as for spheroidization of vitrified material and more generally of metallic and ceramic powders.
The raw particles have been injected from top of the plasma torch, along its axis and in the plasma region by means of a water cooled injection probe has been set in a suitable axial position with respect to induction coil in dependence on powder sample and powder flow rate, in accordance with results of plasma behaviour obtained by means of a 3-D numerical simulation code developed by the research group and with the final aim of minimizing powder loss on plasma containment tube and chamber.
The invention allows to obtain:
- powders with higher particle size (1P) more homogeneous than the finer ones (2P) and in particular for the larger powder the treatment in the second chamber (2C) produces a more regular spherical shape than the first chamber (1C). The dimensions of the main spheres are between 60 and 130 Um for this samples, confirming the starting particle size of 75<x<125 Um.
- powders with finer particle size showing a less homogeneous distribution of the spheres confirming the larger Gaussian curve characteristic of particle size distribution. The dimensions of the spheres after the treatment in chamber 1 are in the range 10-90 Um, while after the chamber number 2 are less than 10Um.