Breakthrough at Imperial College London

Geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues

As part of a major Technology Strategy Board (UK) funded project Imperial College London, in collaboration with Tetronics Ltd, has completed research on the production of geopolymers from DC plasma treated air pollution control (APC) residues. APC residues are a hazardous waste produced from the cleaning of gaseous emissions at Energy from Waste (EfW) facilities processing Municipal Solid Waste (MSW). APC residues have been blended with glass-forming additives to facilitate the formation of a vitreous product and treated using DC plasma technology. This produces a calcium aluminosilicate glass (APC glass) which was used as the raw material for the production of geopolymers. Work has shown that high strength geopolymers can be formed. The broad particle size distribution of the milled APC glass used in the experiments resulted in a microstructure that contains un-reacted APC glass particles included within a geopolymer binder phase. Due to the high calcium content of the APC glass the binder phase formed a three dimensional geopolymeric network that contains hydration products including C-S-H gel which contribute to the excellent final mechanical properties of the material. The research demonstrates, for the first time, that glass derived from DC plasma treatment of APC residues can be used to form high strength geopolymer-glass composites, and these have potential to be used in a range of applications. DC plasma process is an integrated sustainable solution for APC residues management, fulfilling the aim of the EU waste policy as it is a recycling/recovery option higher in waste hierarchy than the existing management options. The use of APC residue plasma derived glass in the production of geopolymers provides a reuse option that promotes resource efficiency and carbon footprint minimisation. More information can be found in the recent publication in the Journal of Hazardous Materials:
Kourti, I., Rani, D.A., Deegan, D., Boccaccini, A.R. and Cheeseman, C.R. (2010) “Production of geopolymers using glass produced from DC plasma treatment of air pollution (APC) residues.” Journal of Hazardous Materials 176(1-3): 704-709.