화학공학소재연구정보센터
Canadian Journal of Chemical Engineering, Vol.77, No.3, 508-514, 1999
Leaching of uranium and Ra-226 from low-level radioactive waste from Port Hope, Ontario
Uranium and radium were leached from a low-lever radioactive soil sample neutralized with limestone from Port Hope, ON, in single stage and multistage leaching tests. The leachants used were alkaline EDTA, sodium citrate, sodium potassium tartrate, acidic ferric chloride, hydrochloric acid, nitric acid and hydrochloric or nitric acid plus boric acid mixtures. All leaching tests except the two-stage acid teachings proved ineffective in yielding leach residues with low residual Ra-226 concentrations of < 100 pCi/g. Leaching with 4 mol/L HNO3 in the first stage followed by treatment with 4 mol/L HNO3 plus 0.05 mol/L boric acid in the second stage proved effective and gave a leach residue with 85 pCi/g Ra-226 and 16 ppm uranium.