| abstract |
The present invention discloses a method of creating a monolithic wasteform consisting of a binder which chemically immobilizes heavy metals and radioactive materials so as to render them environmentally safe. An apatite or apatite-like material may be employed in immobilizing the hazardous material. A preferred practice of the invention employs a hydroxyapatite or a calcium depleted hydroxyapatite into which the waste materials are substituted and immobilized. The stoichiometric apatite or calcium deficient hydroxyapatite may be formed in the aqueous solution containing heavy metals or radioactive materials, or both, wherein binding of the latter is effected. Alternatively, a preformed calcium deficient phosphate may be introduced into the solution having heavy metals or radioactive materials, or both, dissolved therein in effecting the desired binding in situ. A high strength monolithic wasteform which may be stored or buried for long-term, safe storage of the hazardous materials is produced. |