Precipitation and Hydrolysis of Uranium(VI) in Aqueous Solutions: Uranyl Nitrate-Potassium Hydroxide-Neutral Electrolyte

The precipitation and hydrolys•is of uranium (VI) in aqueous solutions of uranyl nitrate - potassium hydroxide - neutral electrolyte, was investigated. Clear and stable systems of uranyl nitrate and potassium hydroxide, were studied , in equivalent concentration of 2 x 10-3 N. The pH value, of the mentioned system was between 5 and 6. By addition of neutral electrolytes (potassium, calcium, strontium, barium, yttrium, and la ntanum nitrate) the precipitation process was initiated and up to 700/o of the uranium present was precipitated. The experimental results showed, that the precipitation of uranium (VI) , in the observed system, was accomplished by several mechanisms, i. e. hydrolysis, coagulation, and formation of mixed uranates