| 摘要 |
A process for chemical fixation of radionuclides and radioactive compounds present in soils and solid materials. Radionuclides and other radioactive compounds are converted to low-temperature Apatite-Group structural isomorphs (general composition: (AB)5 (XO4)3 Z), usually phosphatic, that are insoluble, non-leachable, non-zeolitic, and pH stable by contacting with a sulfate, hydroxide, chloride, fluoride and/or silicate source and with a phosphate anion in either a one or two step process. In the preferred embodiment, soils or contaminated materials containing radionuclides and radioactive wastes are contacted with technical grade phosphoric acid (TGPA) which contains sulfates as an impurity. The Apatitic-structure end product is chemically altered from the initial material and reduced in volume and mass. The end product can be void of free liquids and exhibits sufficiently high levels of thermal stability to be effective in the presence of heat generating nuclear reactions. The process occurs at ambient temperature and pressure.
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