动态膜电解制备四价铀中电流效率的讨论

摘要

The preparation of uranous ion from uranyl nitrate at different current densi-ties (40-160 mA/cm2 ) was investigated in this paper .The results show that membrane electrolysis can ensure high uranyl conversion ratio and maintain high current efficiency during most time of the electrolysis process .However ,in the latter part of the process (most of the uranyl ions are converted to uranous ion ) ,w hen current density is high , current efficiency declines rapidly ;low current density is beneficial to maintain high current efficiency .T herefore ,a preprogrammed automatic control for a step decreasing current density was studied to improve the current efficiency further .Compared with the constant current density ,the step decreasing current density can effectively improve the current efficiency of the electrolysis process and reduce side reactions .%进行了不同电流密度（40～160 mA/cm2）下电解制备四价铀的研究。研究结果表明，采用动态膜电解制备四价铀，能在保证六价铀转化率的前提下维持较高的电流效率，最终保证了四价铀制备过程的高效率。但在电解过程后期（大部分六价铀已转化为四价铀），若采用高电流密度，电流效率迅速下降，而采用低电流密度时仍能维持较高的电流效率。为进一步提高四价铀制备过程的电流效率，研究了程序控制电流密度阶梯减小的电解方式对电解过程后期的电流效率的影响。研究结果表明，与恒定电流密度电解方式相比，采用阶梯形减小电流密度的电解方式，可有效地提高电解过程的电流效率，有助于减少副反应的发生。