Preparation technology and properties of sludge-high calcium coal waste geopolymer

In terms of the geopolymer is a new type of cementitious materials, which has a low carbon emission and a less energy and resource consumption, the preparation technology has attracted much attention.The geopolymer was prepared by the thermal activated sludge and high calcium coal waste, the reaction mechanism and property of this kind of geopolymer were comparative analysed to that of geopolymer which was prepared by high calcium fly ash and gangue, then the optimal technological parameters were determined. Raw material composition and properties of the prepared geopolymer were deeply analysed by XRD, SEM, TG-DTA and FTIR.The results show that the compressive strength of the geopolymer is higher when 40% coal waste is replaced by thermal activated sludge (<50 μm) at 900℃ for 45 min. In complex geopolymeric matrix, amorphous geopolymeric gel covers around the spherical fly ahs granule, similar zeolite mineral forms, and asymmetric stretching Al—O/Si—O bonds and Si—O—Si/Si—O—Al bending band appear obviously.