CONTINUOUS PRECIPITATION OF URANIUM WITH HYDROGEN-PEROXIDE

Three different continuous processes were developed for the recovery of uranium from sulfate-containing simulated mill solutions. In all cases, a high-quality product, low in molybdenum and vanadium, which could be filtered and dried easily, was obtained. The presence of sulfate slows the precipitation rate and results in larger precipitated particles, which is an advantage in filtering and drying the precipitate. The morphologies of the large particles produced in the processes described in this report suggest that crystal growth predominated over nucleation in the precipitator. At 60 °C, the uranium peroxide precipitated as the dihydrate, but below 50 °C to 60 °C, the tetrahydrate was formed, and this knowledge led to important conclusions regarding the rate of the precipitation. A variety of particle morphologies was found, the most unusual being spherulitic aggregates consisting of needles radiating from a common point at the center of the particle. © 1990 The Minerals, Metals & Material Society.