A kind of phenoxycarboxylic acid rare earth solution aluminum removal extractant

Abstract

The present invention relates to a kind of phenoxycarboxylic acid extraction agent for efficient aluminum removal in rare earth solution, which has a typical structure of benzene ring and carboxylic acid group, wherein a carbon atom on the benzene ring is connected with carboxylic acid oxygen functional group (‑O‑(CH 2 ) n ‑COOH), the other five carbon atoms are connected to R1, R2, R3, R4 and R5 functional groups respectively, and the effective component is a single compound. Phenoxycarboxylic acid, cosolvent, and diluent are used to form a phenoxycarboxylic acid-cosolvent-diluent to extract the aluminum removal system of the organic phase, which has the characteristics of preferentially extracting aluminum ions, and can achieve efficient removal of impurity aluminum ions in rare earth solutions. The extraction agent has the characteristics of single active ingredient, small pKa value, stable extraction performance, etc., and is suitable for use as an efficient aluminum removal extraction agent for rare earth solutions.

Description

【Technical field】 [0001] The invention relates to a rare earth solution high-efficiency aluminum removal extractant, in particular to a phenoxycarboxylic acid extractant with a low pKa value, belonging to the field of rare earth extraction and separation. 【Background technique】 [0002] Rare earth and aluminum elements are often associated together, such as the southern ionic rare earth ore contains a large amount of Al(H 2 O) 3+ 6 and Al(OH) n (3-n)+ The form of aluminum adsorbed on the ore, northern bastnaesite also contains a large amount of aluminum, which is similar to rare earth metals in nature, and is often leached together with rare earth metals, making the impurity aluminum content in the rare earth solution 0.1-10g / L; Another example is that NdFeB waste often contains aluminum impurities brought in during the material manufacturing process. In the solution after hydrochloric acid leaching, the aluminum content is 0.5-5g / L; another example is rare earth mines a...

AI Technical Summary

Problems solved by technology

However, the raw material of chlorinated naphthenic acid is still a mixture of naphthenic acids, the problem of complex components has not changed fundamentally, the water solubility of some components and the active reactivity of some chemical bonds have not changed, and the long-term operation of the aluminum removal process of this system does not Stablize

[0005] Patent CN1710119A discloses a long-chain fatty acid as an extractant, alcohols or N235 or petroleum sulfoxide as a cosolvent, and kerosene as a diluent to form a long-chain fatty acid-cosolvent-kerosene extraction organic phase aluminum removal system. Long-chain fatty acids belong to C18 unsaturated fatty acids, and there are two typical disadvantages. One is that long-chain fatty acids are very easy to form esters and water-insoluble precipitates with metal ions, which is difficult to use stably in industry; the other is that long-chain fatty acids themselves have monotonous or polyunsaturated bonds. These unsaturated bonds are easy to oxidize and break in complex environments such as metal ions, acids, and alkalis. The extraction agent is extremely unstable, and it is difficult to achieve the goal of aluminum removal in a long-term and stable manner.

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