Efficient extraction method for high-purity lanthanum oxide

Abstract

The invention relates to an efficient extraction method for high-purity lanthanum oxide. The efficient extraction method comprises the following steps of (1) extraction: mixing a lanthanum oxide feedliquid with an extraction agent at a volume ratio of 1:(2.5-3.5) for extraction separation, carrying out ultrasonic dispersion for 10-15 min, and carrying out separation after standing, wherein the extraction agent comprises the following raw materials including, by volume, 20%-24% of P507, 10%-15% of 1,2,5-thiadiazole-3,4-dithiol and the balance kerosene; (2) back extraction: carrying out back extraction on an oxalic acid solution with the organic-phase volume being 3.0-4.0 times at 50-60 DEG C, carrying out ultrasonic dispersion for 20-30 min, carrying out precipitation, and carrying out filtration to obtain a precipitate; and (3) oxidation: carrying out burning oxidation on the obtained precipitate at 800-900 DEG C for 12-15 h so as to obtain lanthanum oxide. According to the efficientextraction method provided by the invention, a specific amount of 1,2,5-thiadiazole-3,4-dithiol is added into an extraction system; through cooperation between the 1,2,5-thiadiazole-3,4-dithiol and the P507, the hydrophobicity of a lanthanum extraction complex can be higher; and accordingly, the entry into an organic phase can be easier, and the extraction efficiency and the distribution ratio canbe improved.

Description

Technical field [0001] The invention belongs to the technical field of rare earth purification, and specifically relates to an efficient extraction method of high-purity lanthanum oxide. Background technique [0002] Rare earth element (rare earth element) is the general name of the 17 elements of scandium, yttrium, and lanthanide in group IIIB of the periodic table. It mainly exists in the form of single mineral. There are more than 250 kinds of industrial minerals that are suitable for current processing conditions. There are only more than 10 species. China's rare earth resources account for 41.36% of the world's rare earth resources, and it is a veritable large country in rare earth resources, which has laid a solid foundation for the development of China's rare earth industry. Traditional rare earth separation methods include step crystallization, ion exchange, and solvent extraction. Now solvent extraction is the main method for rare earth separation. The step-by-step cry...

AI Technical Summary

Problems solved by technology

The fractional crystallization method uses oxidation or reduction reactions to precipitate step by step, which requires lengthy and complicated crystallization steps, which is not conducive to the production of large amounts of rare earths; the ion exchange method is only suitable for rare earth solutions with low solubility

The characteristics of solvent extraction technology: simple equipment, simple and fast operation, high recovery rate, good purity, good selectivity, wide range of applications; in addition to being used for separation, it can also be used as a means of concentration. The disadvantage of this method is that the toxicity of the organic solvent is high, and the multi-stage extraction operation is time-consuming, troublesome and intensive; some reagents are expensive and the cost is high

[0003] At present, the most widely used extraction agents in industry are acidic extraction agents, such as P204, P507, Cyanex272 and naphthenic acid and other organic reagents, but the extraction efficiency is not satisfactory and needs to be further improved