Alkali-activated fly ash matrices for lead immobilisation: a comparison of different leaching tests

The present paper reports on the lead stabilisation capacity of certain new containment systems, in which fly ash from steam power plants is activated (made to set and harden) with high-alkalinity solutions. Lead is immobilised in such systems because it is precipitated as a highly insoluble silicate. Results are reported from various leaching trials conducted to determine the amount of lead fixed by activated fly ash systems. Finally, the nature of the initial fly ash is another factor found to have a significant impact on the effectiveness of lead fixation in these systems.