| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To separate and recover a silica ingredient and uranium from radioactive solid waste with high efficiency. <P>SOLUTION: The silica ingredient is used as a main ingredient, and a specific ratio of NH<SB>4</SB>F-HF powder is mixed to the powder of the radioactive solid waste containing uranium of hundreds ppm to a few percent. The mixed powder is charged into a hermetic container, and its inside is heated in a specific condition while making its inside an inactive gas atmosphere to react the silica ingredient with NH<SB>4</SB>F-HF and volatilize the former as (NH<SB>4</SB>)<SB>2</SB>-SiF<SB>6</SB>. The total weight of discharged (NH<SB>4</SB>)<SB>2</SB>-SiF<SB>6</SB>is recovered by passing a gas containing (NH<SB>4</SB>)<SB>2</SB>-SiF<SB>6</SB>which is discharged from the container through a cooling means to solidify most of the (NH<SB>4</SB>)<SB>2</SB>-SiF<SB>6</SB>and then putting the gas into contact with an absorbent of a scrubber to allow it to absorb the remainder of (NH<SB>4</SB>)<SB>2</SB>-SiF<SB>6</SB>. The nonvolatile powder remaining in the container after the heating is recovered, a mineral acid solution is added to the nonvolatile powder to dissolve it and a purification treatment is given to the uranium in the solution by using a process such as an ion exchange method. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
