A process for extracting metal values, especially zinc values, from aqueous solutions of metal salts, which comprises contacting the aqueous solution with an organic phase comprising a compound of the formula, ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently, represents an optionally substituted hydrocarbyl or hydrocarbyloxy group or R.sup.1 and R.sup.2 together with the attached phosphorus atom and/or R.sup.3 and R.sup.4 together with the attached phosphorus atom from a 5- to 8-membered heterocyclic ring.
一种从
金属盐的
水溶液中提取
金属价值,特别是
锌价值的方法,包括将
水溶液与一个有机相接触,所述有机相包括下式化合物:##
STR1## 其中,R.sup.1,R.sup.2,R.sup.3和R.sup.4分别独立地表示可选取代的烃基或烃
氧基,或R.sup.1和R.sup.2与所附的
磷原子以及/或R.sup.3和R.sup.4与所附的
磷原子形成5-至8-成员杂环环。