Process for extracting rare earth element by non-saponifiable phosphorous mixing extractant

Abstract

The extraction and separation method for rare-earth element comprises: with rare-earth solution contained a plurality of rare-earth elements as material, preparing mixed extractant with the non-saponifiable P204 and one or two from P507, P229, P350, TBP, C272, C301, C302 and HEOPPA; in the mixed solution with rare-earth sulfate solution, or rare-earth sulfate and rare-earth chloride solution and rare-earth nitrate solution, extracting and separating rare-earth elements. This invention eliminates saponification to overcome pollution, reduces acidity to improve rare-earth concentration, and decreases the main material consumption more than 30% compared with the technique with NH4HCO3 and P507.

Description

technical field [0001] The invention relates to a process for extracting and separating rare earth elements. Specifically, the rare earth solution containing various rare earth elements obtained from the treatment of rare earth ores is used as raw material, and one or both of non-saponifiable P204 and non-saponifiable P507, P229, P350, TBP, C272, C301, C302, and HEOPPA are used. The invention relates to a process for extracting and separating rare earth elements in rare earth sulfuric acid solution or a mixed solution of rare earth sulfuric acid solution, rare earth chloride solution and rare earth nitrate solution with a prepared mixed extractant. Background technique [0002] Lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium, and scandium are collectively called rare earth elements. Their properties are very similar, except for promethium. Except for non-exist...

AI Technical Summary

Problems solved by technology

The first and second methods have good separation effects and are widely used, but they must be saponified with ammonia water, sodium hydroxide, ammonium bicarbonate, etc., which will produce a large amount of ammonia nitrogen wastewater and cause great pollution to the environment.

The third method is the process adopted by France Rhodia and American Molybdenum Company. It is derived from the rare earth nitrate solution obtained when processing monazite ore to separate rare earth. The concentration of nitric acid in the extraction system of this process is high, so the production cost is high. stop state

The fourth process was invented by Beijing General Research Institute of Nonferrous Metals. It is applied to the extraction and separation of rare earth elements from the sulfuric acid rare earth solution obtained when treating Baotou rare earth mines with sulfuric acid method. Less consumption, but due to the low concentration of rare earth in the sulfuric acid system (<45g / L), the investment in equipment extraction agent is large; P204 has a strong extraction ability under acidic conditions, and it is easy to emulsify when the acidity of the feed liquid is low, so a certain amount of acid needs to be added during extraction , while medium and heavy rare earth stripping is very difficult, the residual acid in the stripping liquid is high, and the acid consumption is large