The hafnium free zirconium manufacturing method by combustion synthesis and molten salt

Nuclear-grade, hafnium-free zirconium metal is used in nuclear reactors for structural purposes and for containing the nuclear fuel. Zirconium is an irreplaceable component because of its very low neutron capture cross section. In this study, rapid and cost effective process for hafnium free zirconium is introduced, in which reduced raw material is directly electrorefined without conversion process. Firstly, ZrSi was prepared by combustion synthesis in which reaction pathway is based on ZrSiO4 + 4Mg initial mixtures under 2.5 MPa pressure of Ar atmospheres. Secondly, Electrorefining was carried out using ZrSi ingot as anode material under LiCl-KCl eutectic molten salt added with ZrF4 for removing ionized Hafnium. Experimental results showed that Hafnium free Zirconium was successfully deposited at cathode electrode, and impurity level including Hf was measured by ICP-AES. The chemical stability of Zr with ZrF4 also investigated to suppress disproportion reaction which is responsible for degrading Zr deposit quality. (author)