1,242,665. Evaporation of radioactive waste liquors. SIEMENS A.G. 25 June, 1969 [29 June, 1968], No. 32189/69. Heading B1B. [Also in Division G6] A liquor, which contains a solid radioactive material in solution or suspension, is concentrated by evaporation until the solids-content is raised to about 12%; a small proportion (e.g. 0.01%) of a film-forming agent such as polyacrylamide is added to the concentrated liquor and about 2% of a binding agent, advantageously bone glue, is dissolved therein, the liquor is then dried. The drying may be carried out on a rotary cylinder which is heated by induction so that it has a surface temperature of about 130‹ to 150‹C., and the dry substance is removed from the cylinder by an adjustable knife. The dry substance can be compressed into a cask.