Alpha-Recoil Nuclides in Acid Leaching Experiments on Radioactive Ores

Abstract

Ore samples (autunite, ningyoite, pitchblende) were sequentially leached in hydrochloric acid and nitric acid, and the concentrations of radioactive nuclides and stable elements in the leachates were measured to determine the leaching fractions of nuclides and the activity ratios between nuclides. Uranium and thorium were leachable in hydrochloric acid and nitric acid, respectively. The activity ratios of ²³⁴U/²³⁸U ²³⁰Th/²³⁸U, and ²²⁶Ra/²³⁸U in the leachates were higher than those in the bulk. The leaching effect of nuclides was enhanced as the number of alpha-decay was increasing. The damages due to alpha-recoil nuclides having a longer half-life were self annealed, decreasing the leaching effect of these nuclides.