Role of chemical analysis in the tonnage scale production of nuclear grade zirconium oxide from zircon

This paper describes various types of unique analytical challenges pertaining to the analysis of raw materials, intermediates and finished products for the large-scale production of nuclear grade zirconium oxide, the precursor to reactor grade zirconium metal production. The various process steps involved in this conversion such as opening up of zircon by caustic fusion at elevated temperature, bringing of zirconium into solution using nitric acid followed by solvent extraction with tri-n-butyl phosphate, precipitation of the pure solution with ammonia and finally calcination of the zirconium hydroxide cake to zirconium oxide are outlined. Different analytical problems that are encountered during development of these processes, the inextricable link between the analysis and the task of production on large scale and the pivotal role of analysis for process control are brought out. The evaluation of materials required to be used in huge quantities like tri-n-butyl phosphate (TBP), washed dried frit, nitric acid, caustic flakes, caustic lye etc during the stages of pre-order assessment and procurement of the supply on bulk scale is described in detail. In the context of procurement of materials on bulk scale, the additional dimension for the purpose of analysis, namely, detection of material mix-up and /or the associated difficulties are also addressed. The analytical challenges arising due to the sample specific parameters and providing a sustainable analytical support to various process plants during the production are furnished