Preparation method of low-thorium lutetium oxide

Abstract

The invention relates to a preparation method of low-thorium lutetium oxide, comprising the following steps of: firstly carrying out 3-10 level of primary countercurrent extraction on lutetium oxide extracted from a solvent as a raw material by adopting an isooctanol or kerosene solution of 0.5-2.0mol / L of N235 extracting agent, and then carrying out 3-10 level of countercurrent washing selective backextraction on organic phases of extracted thorium by adopting 0.1-2mol / L of alkali abluent solution; then separating the low-thorium lutetium oxide by a kerosene solution of 0.1-1.0mol / L of another extracting agent, carrying out 3-10 level of countercurrent washing selective backextraction on the organic phases of the extracted thorium by adopting 0.5-2mol / L of acidic abluent solution, carrying out oxalic precipitation, washing and dehydration on aqueous-phase lutetium oxide after thorium removal, and burning at the condition of 750-1000 DEG C to obtain a product, namely, the low-thorium lutetium oxide. In the method, rare earth and thorium are thoroughly separated, and the organic extracting agent is low in price.

Description

(1) Technical field [0001] The invention relates to a method for continuously producing low-thorium lutetium oxide by solvent extraction and separation of lutetium oxide raw materials with high thorium content. It belongs to the technical field of hydrometallurgy. (2) Background technology [0002] Lutetium oxide is a very important rare earth material, widely used in optical glass, electronic components and magnetic materials and other fields. Since the rare earth ore contains relatively high thorium oxide, more than 90% of the thorium oxide is enriched in the lutetium oxide product after extraction and separation by extraction agents such as P507, and the content of thorium is about 10-500 μg / ml, while in Precipitants commonly used in the rare earth separation industry (such as oxalic acid, ammonium bicarbonate) are difficult to remove thorium oxide therein, and the removal rate is less than 5%, so that most of the thorium oxide in the rare earth ore goes into the lutetiu...

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Problems solved by technology

The patent only mentions that the rare earth nitrate liquid is suitable for this process, and does not mention other acidic rare earth materials; the extraction vessel of this process is a kettle type, tank type or tubular container, and an ultrasonic generating device is installed at the same time, so it is difficult to realize continuous production. Even if continuous production is realized, the equipment investment is very huge; this process can achieve a recovery rate of 90% of thorium, uranium mixture and rare earth, which shows that the separation of rare earth and thorium is not complete, and the content of thorium in rare earth is also relatively high , the patent does not mention what level of thorium content in rare earths after separation