Preparation method of high-purity yttrium oxide

Abstract

The invention relates to a preparation method of high-purity yttrium oxide, belonging to the field of rare earth separation technologies. The preparation method comprises the following steps: putting a rare earth chloride solution containing Ho, Er, Tm, Yb, Lu and Y enrichments and tertiary amine into a vessel with a stirring device, and stirring; putting a first extraction agent and the pre-treated rare earth chloride solution into a vessel with a stirring device, and standing until phase splitting, thus obtaining a pre-equilibration solution; adding pure water into the pre-equilibration solution, evenly stirring to obtain an yttrium-enriched material, and controlling the mol concentration of the yttrium-enriched material; taking the yttrium-enriched material as a raw material, and performing continuous extraction separation by using a second extraction agent and adding a washing solution, a reverse extraction solution and liquid alkali, thus obtaining a crude yttrium chloride solution; taking the crude yttrium chloride solution as a raw material, performing successive extraction separation by using a third extraction agent and adding a washing solution and a reverse extraction solution, thus obtaining a high-purity yttrium chloride solution; introducing the high-purity yttrium chloride solution into a precipitation tank; and introducing solid yttrium oxalate into a roller type tunnel kiln, and firing to obtain the finished product. The preparation method embodies cyclic utilization of waste water and environment protection.

Description

technical field [0001] The invention belongs to the technical field of rare earth separation, and in particular relates to a preparation method of high-purity yttrium oxide. Background technique [0002] Yttrium oxide (yttrium oxide) belongs to rare earth oxides, the chemical formula or molecular formula is: Y 2 o 3 ; Molecular weight: 225.81; Density: 5.01g / ㎝ 2 ; Melting point: 2410℃; Properties: white slightly yellow powder; Physical and chemical properties: insoluble in water and alkali but soluble in acid. [0003] As an important functional material, yttrium oxide is used in aviation, aerospace, atomic energy, high-performance ceramics, microwave magnetic materials, optical glass, high-brightness phosphors for large-screen TVs, picture tubes, LEDs, infrared lenses and even military weapons such as infrared guidance. Missile windows and fairings and other areas. [0004] The technical information on the preparation methods of yttrium oxide can be seen in the publish...

AI Technical Summary

Problems solved by technology

As known in the industry, the purity of yttrium oxide is not only related to the brightness of the luminescent material, but also related to the service life of the product. However, the purity of yttrium oxide in the prior art is relatively low, about 99.99%, so that its purity can reach The preparation method of ≥99.9995%, that is, the preparation method with a purity of five nines, has not been reported so far

[0006] At present, there are many manufacturers producing yttrium oxide in my country, and the method used is generally extraction and separation. In the extraction and separation process, in order to ensure the yield as much as possible, the amount of acid and alkali consumed is relatively large, so the raffinate in the extraction process contains The discharge of acid wastewater is relatively large

In order to avoid damage to the environment, the raffinate acid-containing waste water is usually neutralized with alkali and then discharged up to the standard, resulting in the following technical problems: first, the cost of waste water treatment is high; cause waste of resources