A kind of environment-friendly yttrium oxide saponification-free extraction method

Abstract

The invention belongs to the technical field of rare earth separation and extraction, and particularly relates to an environment-friendly yttrium oxide saponification-free extraction method. The method sequentially includes the steps of attapulgite modification, ion exchange, extraction, re-extraction, sedimentation, oxidization and the like. By means of the method, an existing alkali liquor saponification process is abandoned, the saponification effect is directly achieved through modified attapulgite, the water-phase balanced acidity is maintained, ammonia-nitrogen wastewater is avoided, extraction is rapid and thorough, extraction agent consumption is lowered, the rare earth product production cost is reduced, and meanwhile the product quality can be well improved.

Description

technical field [0001] The invention belongs to the technical field of rare earth separation and purification, and in particular relates to an environment-friendly saponification-free extraction method of yttrium oxide. Background technique [0002] Rare earth element (rare earth element) is the general term for 17 elements of scandium, yttrium, and lanthanide in group IIIB of the periodic table of elements, mainly in the form of single minerals. There are more than 250 kinds of industrial minerals that are suitable for current dressing and smelting conditions. There are only more than 10 species. China's rare earth resources account for 41.36% of the world's total, and it is a veritable country with rare earth resources, which has laid a solid foundation for the development of China's rare earth industry. Traditional rare earth separation methods include fractional crystallization, ion exchange, and solvent extraction, but now solvent extraction is the main method for rare...

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 extractant in industry is acidic extractant, such as P204, P507, Cyanex272 and naphthenic acid and other organic reagents, and requires extraction and separation under low acidity conditions, and its extraction capacity is inversely proportional to the equilibrium acidity of the water phase. Generally, to extract a rare earth ion, three hydrogen ions need to be replaced into the water phase, which increases the acidity of the water phase and affects the continuous extraction. Therefore, the extraction agent must be saponified with ammonia water or sodium hydroxide lye to remove the hydrogen ions, and then Then exchange and extract with rare earth material liquid

However, the saponification process not only consumes a large amount of alkaline substances, resulting in an increase in production costs, but also produces a large amount of ammonia nitrogen wastewater, causing serious pollution to water resources. This is a major problem in the rare earth separation industry at present.