Process for stabilizing metals in ash

摘要

A process for stabilizing metals in ash to prevent leaching of the metals is disclosed. The pH of an aqueous slurry of ash is reduced to less than 5 in the presence of an iron salt. The pH-reduced slurry is then treated with an organo sulfur containing compound and an alkaline earth metal oxide or hydroxide in specific weight proportions relative to the iron salt and to each other.