Thermal transformation of aluminosilicate gel and ZrO2-SiO2 gel containing ruthenium hydroxide

Processing of ruthenium with aluminosilicate and ZrO2-SiO2 gels has been studied in order to convert the high level liquid waste and the scrubber liquid waste into the solidified products. Thermal transformations of gels containing ruthenium oxide were examined by means of differential thermal analysis, thermogravimetric analysis and X-ray powder diffraction. Ruthenium hydroxide was converted into ruthenium oxide by calcination above 3000C. Aluminosilicate gels containing ruthenium hydroxide were converted into RuO2-mullite at 1,0000C for 3hr. Zirconia-silica gels containing ruthenium hydroxide were converted into RuO2-ZrO2(tetragonal)-SiO2(amorphous) at 1,0000C for 3hr. Solidified RuO2-mullite and RuO2-ZrO2(tetragonal)-SiO2(amorphous) show no thermal transformation under 8000C, therefore, these calcined materials gain resistance to large heat evolution from the high level solid wastes. (J.P.N.)