Extraction separation method for rare earth and zinc in reverse extraction raffinate obtained in reduction extraction separation of europium

Abstract

The invention relates to an extraction separation method for rare earth and zinc in reverse extraction raffinate obtained in reduction extraction separation of europium, belonging to the field of hydro-metallurgy of rare earth. According to the invention, the reverse extraction raffinate obtained in reduction extraction separation of europium is mixed solution of rare earth chloride and zinc chloride; ammonia water is added into the reverse extraction raffinate to neutralize spent acid, then NH4Cl is added, and then the reverse extraction raffinate with NH4Cl is used as a feed liquid, wherein the concentration of NH4Cl in the feed liquid is 3 mol/L; an organic phase is composed of P507-kerosene with a concentration of 1.5 mol/L; a GdCl3 solution with NH4Cl is used as a washing liquid, and the concentration of NH4Cl in the washing liquid is 3 mol/L; after multistage extraction separation, raffinate containing zinc and an organic phase with loaded rare earth are obtained, wherein the raffinate containing zinc is used as a raw material for preparation of zinc carbonate, and the organic phase with loaded rare earth is directly used as a feed liquid for extraction separation of samarium, europium and gadolinium. NH4Cl is added into the extraction separation feed liquid for rare earth and zinc and into the washing liquid, so a separating factor for rare earth and zinc is improved, the stages of extraction separation in industrial production and the volume of a mixing chamber can be reduced, and consumption of acid and alkali is decreased at the same time.

Description

technical field [0001] The invention relates to a method for extracting and separating rare earth and zinc in the stripping raffinate of europium by reducing, extracting and separating europium, and belongs to the field of rare earth hydrometallurgy. Background technique [0002] At present, the production process of fluorescent grade europium oxide in China mainly uses the europium-enriched solution obtained from the three outlets of samarium-europium-gadolinium extraction and separation as the feed solution, and most enterprises use zinc powder to reduce the Eu in the europium-enriched solution. 3+ Preparation of europium oxide process, adding zinc powder to the rich europium solution to make Eu 3+ reduced to Eu 2+ , while zinc powder transforms into Zn 2+ Into the rare earth solution, containing Zn 2+ The rare earth solution of the reduction extraction is used as the feed liquid of the reduction extraction, and in the reduction extraction separation section Zn 2+ As a...

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Problems solved by technology

CN1715430A patent and the preparation of zinc and rare earth separation and basic zinc carbonate written by Li Huiqin, Rare Earth, 2006, 27 (6): 62-64, provide a kind of zinc and rare earth separation method, utilize N235Realize the separation of Zn2+ and RE3+; Japanese patent JP2001151743 reported adding tris(2-aminoethyl) to the mixed solution of rare earth and zinc After the reaction of amine and salicylaldehyde, only the rare earth crystallizes out, thus realizing the separation of rare earth and zinc; the separation of rare earth and zinc can also be done by adding excessive ammonia water or sodium hydroxide, the rare earth forms a hydroxide precipitate, and Zn 2+ forms ZnO22- and remains in the solution. The disadvantage of this method is that rare earth hydroxide precipitates easily form colloids, which is difficult to filter. It is very easy to entrain Zn2+, and the operation process is cumbersome and uneconomical, so it is difficult to implement in industrial production