Recovery and purification of uranium from slags produced in UF6 production reactor

Abstract

In this paper, for recovery and purification of uranium from the slag, three simple operations, including heat treatment at low temperature, leaching operations at the ambient temperature, and uranium sedimentation in conventional methods, as well as the combined sedimentation method at the ambient temperature were proposed. The overall role for each of these operations has been studied on the purity of the manufactured products. During the heat treatment, the combination of the insoluble U4+ in the slag structure was oxidized to soluble uranium compounds. Then, with the leaching process and using a dilute nitric acid solution, ammonium bicarbonate solution and methanol, the separation of uranium from the saturated solid phase was performed. The leached uranium in the presence of the fluorine ions in the form of AUC(ammonium uranyl carbonate), ADU(ammonium diuranate) was precipitated with high purity and high efficiency, and a very pure U3O8 containing fluorine concentrations of less than the permitted limit in the nuclear fuel pellet was used. The results of the analysis of the U3O8 shows that the elements that affect the uranium enrichment process and the fuel performance is decreased under the permitted limit.

Keywords

• recovery
• purification
• uranium
• uf6 production reactor