Process for separating rare-earth element by extraction

Abstract

The invention mixes and pre-extracts the mixed solution of acidic organic extractants such as P507, P204, C272, and naphthenic acid with magnesium bicarbonate and / or calcium bicarbonate solution and rare-earth solution. The rare-earth ions are extracted into the organic phase, then the loaded organic phase containing rare-earth ions are obtained through clarification, and can be used for the extract separation of the mixed rare-earth feed liquid. After a plurality of different levels of extraction, washing, stripping, single rare-earth compounds or rare-earth elements-containing enrichments can be obtained. The magnesium bicarbonate and / or calcium bicarbonate solution are prepared by roasting, digesting, carbonizing magnesite, limestone, calcite, dolomite and similar minerals, so that the content of impurities, such as silicon, iron, aluminum is lower. Ternary phase sediment is not produced in the pre-extraction and extraction separation process, so that the purity of the rare-earth products are not affected. The organic phase does not need ammonia saponification and does not produce ammonia-nitrogen wastewater. By adopting the invention, the production cost of rare-earth products is greatly lowered and the cost for three waste disposal is also greatly saved.

Description

technical field [0001] The invention relates to a process for extracting and separating rare earth elements with an acidic organic extractant. Specifically, the acidic organic extractant is mixed with magnesium bicarbonate and / or calcium bicarbonate aqueous solution and rare earth solution for pre-extraction, and the rare earth ions are extracted into the organic phase, and after clarification, a loaded organic extractant containing rare earth ions is obtained. The invention relates to the extraction and separation of mixed rare earth feed liquid, and belongs to the field of rare earth solvent extraction and separation. Background technique [0002] At present, the separation and purification of a single rare earth element in industry generally adopts solvent extraction. Phosphoric acid), C272 (two (2,4,4-trimethylpentyl) phosphonic acid) and other extractants extract and separate rare earth elements in hydrochloric acid system ([1] Collected Papers on Rare Earth Chemistry,...

AI Technical Summary

Problems solved by technology

[0009] The above three invention patent applications use alkaline earth metal minerals containing calcium and magnesium, or alkaline earth metal compound powder or slurry containing magnesium and / or calcium, that is, containing magnesium and / or calcium oxides, hydroxides, carbon Salt powder or water slurry is used to pretreat or pre-extract the organic phase. Since alkaline earth metal minerals containing calcium and magnesium and their oxides and hydroxides contain more impurities such as silicon, iron, and aluminum, solid-liquid reaction The speed is slow and incomplete, resulting in three-phase substances in the pretreatment or extraction process, which affects the smooth progress of the extraction process, and impurities such as iron and aluminum are easily extracted into the organic phase, thereby affecting product quality

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