Valorization of coal fly ash by mechano-chemical activation: Part II. Enhancing pozzolanic reactivity

The pozzolanic and adsorptive characteristics of coal fly ash have been enhanced by mechano-chemical activation in order to evaluate their potential utilization in the stabilization/solidification treatment of hazardous wastes. To that aim a soil artificially contaminated by large amounts of Phenol and Pb underwent that treatment, wherein increasing amounts of powder activated carbon and Portland cement were substituted by mechano-chemically activated fly ash. Under the experimental conditions investigated, very encouraging results, in terms of contaminants leaching and mechanical properties of the stabilized/solidified matrix, were obtained when up to 100% of the powder activated carbon and up to 50% of the Portland cement were substituted by mechano-chemically activated fly ash, thus opening improved possibilities for using this latter in environmental applications.