Patent Number: 048511560
Section: description

The following example further illustrates this invention. EXAMPLE About 0.2 kg. borosilicate glass formers consisting of about 30% Si0.sub.2, 33% Na.sub.2 B.sub.4 0.sub.7, and 3% A1.sub.2 0.sub.3 were added per kilogram of nuclear waste material using 100 gram samples of the shredded waste material. The waste material consisted of 35% cellulose, 25% rubber, 40% plastic, and about 5% ruthenium as RuC1.sub.3. Sufficient concentrated sulfuric acid was added (about 1000 ml. for each 100 gms. of waste treated) to fluidize the waste. The mixture was heated at 300.degree. C. for one hour which formed a carbon dispersion. A sample of the residue was then assayed to determine the ruthenium loss, which was determined to be 1%. The residue was then heated at 400.degree. C. for 4 hours to evaporate the sulfuric acid. To remove the sulfates, one sample of the residue was heated at 700 to 800.degree. C. for 2 hours. An assay at that time determined that the ruthenium loss was an additional 10%. This sample was then heated at 1100.degree. C. for 2 hours to form glass. No additional loss of ruthenium occurred during the formation of the glass. Another sample which had not been desulfated was pressed into a wafer at 1000 psi at room temperature. The wafer was then sintered at 800.degree. C. for 2 hours to form a ceramic. This resulted in an additional loss of 4% of the ruthenium. Thus, the ceramic treatment had a total retention of ruthenium of 95 to 96% while the glass treatment had a retention of 89 to 90%.