N-263对钨和钼的萃取机理研究与平衡pH的选择

本文对N-263在萃取钨和钼的过程中发生的萃取机理与pH值的改变进行了测量和研究。试验结果表明，季铵盐，N-263，在从钨酸钠溶液中萃取钨和钼的过程中，萃取前pH与萃取后的平衡pH之间发生了规律性改变；平衡pH对于分配比与分离系数的影响起到了至关重要的作用。严格控制萃取反应的平衡pH值，不仅影响到分配比，而且，影响到化学性质相近的钨和钼之间的分离效率。萃取剂，N-263对于钨和钼等阴离子的萃取反应和机理，是由萃取终点的平衡pH决定的。对于酸性溶液而言，萃取过程发生pH的升高现象，对于碱性溶液而言，萃取将发生pH的下降现象。萃取机理研究表明，萃取钨的最佳平衡pH为7。如果将溶液萃取前的pH值调整到接近中性，那么平衡pH变化极小。

STUDY ON THE CONTROL METHODS OF EQUILIBRIUM pH IN THE EXTRACTION AQUEOS PHASE

This paper studies on the extraction separation of molybdenum from sodiun tungstate using the N - 263 as extraction agent and hydrogen peroxide as complex agent , as well as using sodium ascobicate as recuction agent containing high concentration molybdenun. The change rule of extraction equilibrium pH, control methods, com- plex scraping and reduction scraping, are respectively investigated . The results indicated that the changes of equi- librium pH determined the distribution coefficient and separation coefficient of easy extraction elements and difficul- ty extraction elements. In order to control the equilibrium pH, the pH of initial aqueous must be low to 7 complex scraping agent and reduction scraping agent must be used.