Process for stabilization of heavy metals in ash

摘要

This invention relates to a process for stabilizing heavy metals in ash. The steps of the process include: (a) preparing an aqueous slurry of ash and water; (b) decreasing the pH of the aqueous slurry to less than about 5.0 in the presence of an iron salt; (c) treating the aqueous slurry with (1) an organo sulfur containing compound, (2) an alkaline extract of peat moss, and (3) an alkaline earth metal containing compound. Heavy metals in ash treated by this process will not leach into the environment.