Geopolymerisation of multiple minerals

Geopolymerisation can transfer large scale alumino-silicate wastes into value-added geopolymeric products with sound mechanical strength and high acid, fire and bacterial resistance. However, due to the complexity of source materials as well as the interaction between source materials during the geopolymerisation, previous studies have mostly dealt with single or bi-component systems, which could potentially narrow the application of this technology. The present work selects three industrial materials, i.e. fly ash, kaolinite and albite to investigate various combinations. The results show that when appropriate reaction parameters are used, the three component system gives geopolymers possessing the highest compressive strength and the lowest probability of cracking. It is believed that the higher reactivity of the fly ash and albite, the interaction between the source materials and the gel phase, and the reinforcing effect caused by the large unreacted albite particles are responsible for this satisfactory mechanical behaviour. (C) 2002 Elsevier Science Ltd. All rights reserved.