Regularities of cathode deposit formation during simultaneous reduction and exchange reactions. Influence of the electrolysis conditions on the concentration of components in the UO_2-ZrO_2 cathode deposit

摘要

This paper represents the experimental data on a quantitative composition of cathode UO_2-ZrO_2 deposits, which are formed through simultaneous electrolytic reduction of UO_2~(2+) ions to UO_2 and the exchange between the UO_2 and Zr~(4+) ions present in the molten (NaCl-KCI)_(equim).-UO_2Cl_2-ZrCl_4 electrolyte. A scheme for the formation of UO_2-ZrO_2 deposits containing up to 98 mol. % of ZrO_2 is provided. The fraction of zirconium dioxide decreased as the ZrCl_4 concentration decreased and as current density and electrolysis times increased. The electrolyte temperature influence on the average composition of the UO_2-ZrO_2 deposit was found to be insignificant. The structure of the cathode deposit was analyzed. The established regularities are explained by the change in the reduction and exchange reaction rates at the cathode.