Abstract:
Anthropogenic pollution is an unavoidable consequence of both producing energy from coal and desalination
of water. Coal ash and brines are partially utilised due to vast volumes and stringent legal environmental
requirements. Therefore innovative management for these wastes is essential. This
manuscript presents the initial results of research showing that brine chemistry dominates the behaviour
of fly ash pastes. The outcome could expand the utilisation of brines in mortars and mass concrete to conserve
potable water. The tests involved varying paste consistency and brine characteristics. The results
demonstrated that chemical composition of brine plays a more important role than salinity in determining
both paste rheology and strength development. An optimum brine salinity range for pastes was
obtained with a specific fly ash. The results suggest that an opportunity exists for utilising industrial
brines rich in Cl and SO¼
4 as mixing waters in the co-disposal or mine backfilling with fly ash pastes. This
would reduce operational costs and liability of energy generation from coal.
