METHOD FOR PROCESSING METAL WASTES CONTAMINATED WITH RADIONUCLIDES Russian patent published in 2001 - IPC

FIELD: waste treatment methods. SUBSTANCE: metal wastes undergo liquid decontamination using for the purpose etching and clarifying solutions and water followed by their smelting in induction furnace with addition of refined fluxes, dosimetry control of ingots, and solidification of etching solution. Liquid decontamination of metal wastes boils down to their sequential treatment with etching solution composed of 5 to 200 g/l of strong acid and 0.1 to 15 g/l of sulfur-containing corrosion activator or inhibitor at temperature ranging between 10 and 100 C, then with clarifying solution that has 2 to 100 g/l of strong acid and 1 to 20 g/l of oxidizer at temperature ranging between 10 and 90 C, and finally with water. In the process etching solution is checked for metal ion concentration. If this concentration exceeds desired value, some portion of etching solution is removed and solidified and strong acid is added to respective portion of clarifying solution to make it stronger. Proportion of refined flux relative to metal during smelting process is chosen between 0.9 and 4 mass percent. EFFECT: enhanced decontamination efficiency. 17 cl, 4 tbl