Extraction of barium and strontium carbonate from barium and strontium molybdate samples using aqueous ammonium chloride

Previous studies have assessed the Ba-Mo-O and Sr-Mo-O systems to understand the behaviour of nuclear fuel at various stages of the nuclear fuel lifecycle. Barium and strontium molybdates have been synthesized using simple solid-state synthesis methods, allowing the study of their different chemical and physical properties. Although various results have been published regarding the aforementioned systems, it is suspected that there is carbonate contamination (BaCO₃ and SrCO₃) in the analyzed samples. Limited literature related to the solubility of strontium and barium carbonate in different solutions has motivated this study to ensure the synthesis of pure (Ba,Sr)_kMo_lO_m solid samples. The purpose of this study is to assess the solubility of (Ba,Sr)CO₃ in ammonium chloride solution in the presence of barium and strontium molybdate, (Ba,Sr)MoO₄, and propose a procedure to absorb the carbonate from the mixed molybdate samples. Preliminary results indicate effective removal of strontium and barium contamination using batch absorption with a 0.5N ammonium chloride aqueous solution. Although, further study of carbonate solubility in ammonium chloride is required in order to optimize the proposed procedure. (author)