Determination of radioactive cobalt in reactor coolant water by solvent extraction

Decontamination of liquid radioactive waste concentrates from 60Co using diethyldithiocarbamates

“…Apparently, Mn(DDTC) 3 is less soluble than Mn(DDTC) 2 , and with the progress of Mn 2+ oxidation to Mn 3+ in the solution, a small amount of the solid phase continues to precipitate. However, this process did not affect the efficiency of the 60 Со removal from the solution by coprecipitation; therefore, 2-h contact was 3 from initial BR at pH 7-8 and 75°C (0.9-1.6) × 10 4 3.5-6.2 UV-peroxide oxidation at 98°C (0.6-1.8) × 10 4 3.1-9.3 UV-peroxide oxidation at 98°C and subsequent coprecipitation with Mn(DDTC) 2 from the filtrate at 75°C and pH [7][8] (1.1-1.4) × 10 3 40-50.9…”

“…The transition metals are isomorphic with Co and form under definite conditions difficultly soluble and weakly dis- sociating diethyldithiocarbamates, which, in accordance with the Fajans-Paneth and Hahn rules, allows the maximal equilibrium coefficients (K eq ) to be attained. It is known that the Me(DDTC) n precipitation depends on the pH interval, solution salinity, kind of metal cation, and temperature [6][7][8]. Because in our case the solution is weakly supersaturated and is vigorously stirred, under these conditions the capture of the microcomponent forming with the macrocomponent a substitution solid solution is described by the DoernerHoskins formula ln (1 -x) = λln (1 -y/y 0 ), where λ is the cocrystallization coefficient approaching K eq L/ρ (L is the macrocomponent solubility at a given temperature).…”