Leaching of 226Ra from components of uranium mill tailings

A sequential extraction procedure was used to characterize the geochemical forms of ²²⁶Ra retained by mixtures of quartz sand and a variety of fine-grained rock and mineral species. These mixtures had previously been exposed to the sulfuric acid milling liquor of a simulated acid-leach uranium milling circuit. For most test cases, the major fraction of the ²²⁶Ra was extracted with 1 mol/1 NH₄Cl and was deemed to be exchangeable. However, ²²⁶Ra retained by the barite-containing mixture was resistant to both 1 mol/1 NH₄Cl and 1 mol/HCHCl extraction.