مجله علوم و فنون هستهای (Feb 2014)
AUC Preparation from ADU Precipitated from Uranyl Fluoride Solution
Abstract
In this study, a simple method for the AUC powder preparation from uranyl fluoride solution, which is more effective for uranium recovery from AUC effluent is presented. At first, the uranium was precipitated in the form of ADU with more than 99.99 percent efficiency by ammonia solution. Then, through overflowing the solution, most of the fluoride ions were removed from the precipitated uranium. By adding ammonium carbonate solution to the ADU slurry, the AUC with stochiometry formula with high efficiency was prepared. The remained uranium in the AUC liquid waste was recovered by ADU precipitation in 99.99 percent. In this step, the uranium concentration in the final waste solution was decreased to less than 1ppm, where it is an important factor for enriched uranium. The ADU slurry was recycled to the next cycle of the AUC production. In this study, the NH4+ concentration, CO32-/UO22+ molar ratio and temperature effects were studied on the properties of the AUC powder and the precipitation efficiency. The results show that the NH4+ concentration is only effective on the fluoride separation and precipitation efficiency. The AUC precipitation efficiency depends on the uranium concentration in the ADU slurry. Also, the uranium recovery depends on the uranium concentration in the AUC waste. Decreasing the CO32-/UO22+ ratio to a minimum value caused the maximum particle size of the AUC crystals to be on an average value of 121 microns. The results of the XRD and SEM for the AUC powder are also presented.
