Purification of Crude Sodium Di-Uranate from Tummalapalle Source, India to Nuclear Grade Ammonium Di-Uranate Using Sulphamic Acid Dissolution Route

Abstract

Crude Sodium Di-Uranate (SDU) of Tummalapalle mine India, contains 2-3% (w/w) of silica besides 5-7% (w/w) of organic matter including polyacrylamides and humic masses with 2-5% Zirconium (Zr) (w/w) as major impurities, hence the direct conversion of SDU, to Nuclear Grade (NG) Ammonium Di-Uranate Cake (ADUC) for fuel fabrication via HNO3-Tributyl Phosphate (TBP) extraction route is onerous due to silica gel creation, third phase inception enounces presence of excess Zr and micro-emulsion formation confirms organic matter introduces difficulties in filtration, recovery and purification stages. Various analytical techniques such as X-Ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) as well as Inductively Coupled Optical Emission Spectrometer (ICP-OES) has been utilized to characterize raw material (SDU), intermediate products (gel and residues) as well as final product (NG-ADUC). In this research; an innovative, novel route for dissolution of SDU employing sulphamic acid (25% w/v) to remove silica, organic matter, and Zr followed by the conventional route to NG-ADU; eliminates the three major process difficulties viz., (i) gelation, (ii) third phase formation and (iii) microemulsion formation. In addition, sulphamic acid extracted Uranium (U)-bearing stream ultimately articulates 99.5% overall U recovery and enunciates nuclear grade U with desirable morphological characteristics.