预分离萃取法及其分离低钇离子稀土矿新工艺

Pre-separation Extraction Method and Its Application in Separating Rare Earth Mixture with Low Yttrium Content

预分离萃取法是首先用少量级数对待分离的原料进行预先分离,然后再流入级数较多的、进行相邻元素间分离的细分离工艺,从而减少进入级数较多的相邻元素分离工艺的料液量。因而,整体工艺的萃取槽体积减少25%～40%,有机相、水相及稀土金属的存槽量减少25%～40%,酸碱消耗也减少30%～40%,废水排放量大为减少。预分离工艺有多种形式,相邻元素间的细分离工艺也有多种类型。本文介绍了预分离萃取法的形成缘由、基本原理,使用这种方法的基本原则和它的各种工艺形式,以及用预分离萃取法分离低钇离子稀土矿的新工艺。

The new pre-separation extraction method for separating multi-component is different from ordinary extraction processes that raw material is firstly pre-separated with less stage of countercurrent extraction and/or countercurrent scrub,then,its raffinate and/or extract directly flow to fractional countercurrent extraction processes for neighboring elements separation with more stages.In this way,the amount of feed to enter the fractional extraction processes for neighboring elements can be reduced largely,the overall volume of all extractor of the whole processes can be decreased by 25%~40%,the process handling capacity with new pre-separation extraction process can be increased by more than 30%,the hold capacity of extractant and valuable rare earth element in extractors of whole processes can be reduced by 25%~40%,the consumption of chemical reagents including HCl and NH3 can be decreased by 30%~40%,the pollution can also be reduced largely.Forming reason and basic principle of the invention and manifold processes of pre-separation extraction method are introduced.