Nb_2O_5和Ta_2O_5在KOH高浓介质体系中的溶解行为

Dissolution Behavior of Nb_2O_5 and Ta_2O_5 in High KOH Concentration Medium

在KOH高浓介质体系中研究Nb2 O5和Ta2 O5的溶解行为 ,探讨KOH浓度、反应温度和浸出时间对Nb2 O5,Ta2 O5及其混合物提取率的影响。结果表明 ,Nb2 O5在KOH高浓介质体系中可生成可溶性的铌酸钾及不溶性的偏铌酸钾。在试验条件下 ,温度一定 ,KOH浓度增加 ,有利于生成可溶性铌酸钾。而KOH浓度一定 ,温度升高 ,有利于生成偏铌酸钾。浸出时间过长也将促使不溶性偏铌酸钾的形成。试验条件下 ,Ta2 O5在KOH高浓介质体系中只得到不溶性的偏钽酸钾。Nb2 O5和Ta2 O5混合物的浸出规律与纯Nb2 O5类似 ,铌、钽不能被选择性地浸出。

The dissolution behavior of Nb 2O 5 and Ta 2O 5 in the high KOH concentration medium is investigated. The effects of KOH concentration, reaction temperature, retention time on the leaching rate of Nb 2O 5, Ta 2O 5 and their mixture are described. The results show that under the condition of the experiments, the high KOH concentration is benefit to the formation of soluble niobate, but the high temperature is favor of the formation of insoluble niobate, and the insoluble tantalate is the sole leaching product of Ta 2O 5. Both Nb 2O 5 and Ta 2O 5 in the mixture are dissolved in the high KOH concentration medium, the leaching behavior of the mixture is just same as the Nb 2O 5, the selectively leaching of Nb 2O 5 and Ta 2O 5 can not be achieved.