Non-rare earth impurity and rare earth element extraction and separation method

Abstract

The invention discloses a non-rare earth impurity and rare earth element extraction and separation method. The method comprises the steps that at first, N235 is adopted for extracting and separating iron in rare earth feed liquid, then a sediment iron removing method is used for eliminating the iron in the rare earth feed liquid completely further, and then unsaponifiable naphthenic acid is adopted for extracting and separating aluminum in the feed liquid; the rare earth feed liquid obtained after the iron and aluminum are separated is extracted and grouped by adopting an extraction agent P507-N235, heavy rare earth elements are separated from light and medium rare earth elements, for feed liquid containing the heavy rare earth elements, unsaponifiable naphthenic acid is adopted for separating yttrium and other heavy rare earth elements, for feed liquid containing the light rare earth elements, the extraction agent P507-N235 is adopted for extracting, grouping and separating calcium, magnesium and the light rare earth elements, and the extraction agent P507-N235 continues to be used for separating other rare earth elements one by one. According to the method, non-rare earth impurities such as iron, aluminum, calcium, magnesium and the rare earth elements are separated completely, acid is utilized comprehensively, the adopted extraction agent does not need to be saponified and can be used directly and circularly, an acid reagent and an alkaline reagent do not need to be added in the extraction process, and the separation cost is very low.

Description

technical field [0001] The invention relates to a method for extracting and separating rare earth elements, in particular to a method for extracting and separating non-rare earth impurities and rare earth elements. Background technique [0002] Rare earth elements have unique electronic structures and optical, electrical, and magnetic properties. The development and utilization of rare earth resources is of great significance for promoting the development of my country's economy. Rare earth ore is the main rare earth resource. During the smelting process of rare earth ore, the separation of rare earth elements from the leachate of rare earth ore is an important step. The commonly used separation method of rare earth elements is solvent extraction. The rare earth industry in my country mostly uses acidic phosphorus-type extractant P507 or P204 as the main extractant to separate rare earth elements. [0003] The traditional separation method using P507 or P204 as the main ex...

AI Technical Summary

Problems solved by technology

However, when the P507-N235 system is used for the extraction and separation of rare earth elements, the existence of non-rare earth impurities will interfere with the extraction process. The iron in the rare earth feed solution can be extracted by both P507 and N235, while the back extraction of iron However, it is very difficult; the aluminum in the rare earth feed solution is easy to hydrolyze, and the existence of hydrolyzed products will lead to the occurrence of emulsification during the extraction process, making it impossible to separate the organic phase and the aqueous phase

In addition, for the extraction and separation of rare earth element yttrium, traditional methods mostly use saponification naphthenic acid system. The saponification process of naphthenic acid also consumes ammonia water, so the process of extraction and separation of yttrium will also produce ammonia nitrogen waste water; while P507-N235 can avoid ammonia nitrogen The production of wastewater, but the separation ability of yttrium is far lower than that of the saponified naphthenic acid system, so the P507-N235 system has little advantage in the extraction and separation of yttrium

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