France has a server where PhD students are invited to upload their thesis. I found an interesting one about the foaming of CRT (cathode ray tubes), already mentioned in a previous post. But in that post, only glass without PbO was foamed.
In the PhD-thesis of this post (written in French by Francois Mear), also PbO containing glass is considered. The following topics are described:
- Glass composition of the different CRT’s
- Description of different and less known glass foaming methods
- Saint-Gobain method based on sulfate
- Saint Gobain – Isover method with a nitrate glasses
- CERNIX with AlN foaming agent
- MISAPOR process with SiC
- Description of foaming tests with SiC and TiN
- Study of the obtained foams
- Study of the foaming kinetics and formation of Pb-metal
In my opinion, the presence of Pb-metal in the foam will never be accepted. This Pb-metal is the result of the reduction of the PbO by SiC and/or TiN. Only foaming methods, based on decomposition (CaCO3) can be a candidate to recycle this glass as cellular glass.