Non-saponification extraction separation method of rare-earth element

Abstract

The invention relates to a synergistic extraction separation method of a rare-earth element, in particular to a non-saponification extraction separation method of the rare-earth element. According to the invention, a non-saponification acid extraction agent (P204 or P507) and an alkaline extraction agent (N1923, N179, N116, DDA and DLA) are mixed according to a certain proportion to form a synergistic extraction agent, after the synergistic extraction agent and a diluent are mixed to react with a mineral acid, deionized water is used for washing the reacted product to be neutral, and the neutral reacted product is used for extraction separation of the rare-earth element. Saponification treatment is not needed to be performed on the extraction agent in the extraction process of the rare-earth element, so that the problems that ammonia nitrogen waste water and the like produced by the saponification treatment pollute environment and the like can be solved; in addition, the technological process is simple to operate, and the production cost is reduced to a certain extent.

Description

technical field [0001] The invention relates to a method for cooperative extraction and separation of rare earth elements, in particular to a method for non-saponification extraction and separation of rare earth elements. Background technique [0002] The 15 elements of the lanthanide series and the 17 elements of yttrium and scandium are collectively called rare earth elements. Because the properties of rare earth elements are similar, it is difficult to separate and purify a single rare earth element. At present, there are many separation processes and methods of rare earth elements in industry, among which solvent extraction method has the advantages of high product purity and yield, less consumption of chemical reagents, good production environment, continuous production process, and easy realization of automatic control. Rare earth separation industry is widely used process method. [0003] The solvent extraction and separation methods of rare earth elements in my coun...

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Problems solved by technology

Patent CN1824814 invented a kind of acidic organic phosphoric acid or organic phosphoric acid ester extractant such as P204, P507, C272, P229, etc. one or 2-3 kinds of mixed extractant prepared in rare earth chloride or rare earth nitrate solution to extract Separation of rare earth elements. When using this method to extract and separate rare earth elements, the organic extractant does not need saponification, and no waste water is generated during the extraction process, which can eliminate the pollution of ammonia nitrogen wastewater to water resources. Although this method replaces the method of saponification with a composite extractant, but The extractants are weakly acidic organic phosphoric acid or organophosphate esters. This method improves the ability of extracting and separating rare earth elements through the synergistic effect of the compound extractant, but cannot adjust the acidity of the aqueous phase. Therefore, in the process of extracting and separating rare earth elements The influence of the compound extractant on the acidity of the solution is still greater

Patent CN101709392A invented a method of reducing the concentration of hydrogen ions in the aqueous solution by diluting the water phase. This method avoids the generation of ammonia nitrogen wastewater and reduces production costs. However, this method also reduces the concentration of hydrogen ions while making The concentration of rare earth feed liquid is reduced, so the production efficiency is also greatly reduced

Xiao Yanfei et al. (XIAO Yanfei, LONG Zhiqi, HUANG Xiaowei. Study on non-saponification extraction process for rare earth separation[J]. Journal of Rare Earths, 2013, 31: 512-516.) used magnesium oxide to adjust the water phase In order to reduce the influence of hydrogen ions on the extraction process, although this method can effectively control the concentration of hydrogen ions in the aqueous phase, the added magnesium oxide is prone to produce a third phase during the extraction and separation of rare earth elements, which seriously affects the rare earth elements. The effect of extraction and separation

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