Abstract: A method of encapsulating hazardous waste materials including heavy metals such as arsenic, mercury, nickel and chromium residues, as well as radioactive materials. The method involves adding the hazardous waste material to a settable composition, forming a slurry, and allowing the slurry to set to encapsulate the waste material. The settable composition is a powdered flowable cement composition containing calcium carbonate and a caustic magnesium oxide. Tests conducted on the encapsulated material indicate that virtually none of the hazardous waste material is leached out of the set composition which has a concrete-like appearance.

Abstract: A dry powdered flowable cement composition contains calcium carbonate and a partially decarbonated magnesium carbonate. A slurry of the composition will set hard with various organic fillers including waste products and toxic waste. The composition can be slurried with contaminated water such as sea water, mineral laden ground water and muddy water. A high percentage of filler can be added while still having an acceptable set.