Method for preparing high-purity terbium oxide

Abstract

The invention discloses a method for preparing high-purity terbium oxide, belonging to the technical field of rare-earth separation. The method comprises the following steps of feeding mixed rare-earth oxide, hydrochloric acid and pure water into a container with a stirring device and a heating device, stirring, and filtering so as to obtain a mixed rare-earth chloride solution; adding the mixed rare-earth chloride into another container with a stirring device, and continuously stirring so as to obtain a separated material; by taking the separated material as a raw material, continuously extracting and separating by using a first extraction agent, a caustic soda liquid and a returning fluid so as to obtain a rich terbium chloride solution; by taking the rich terbium chloride solution as another raw material, adding a second extraction agent and the returning fluid, further extracting and separating so as to obtain a high-purity terbium chloride solution; introducing the high-purity terbium chloride solution into a settling pond, and filtering so as to obtain solid oxalate terbium; and introducing the solid oxalate terbium into a roller table type tunnel kiln for firing, controlling the firing temperature and the firing time, discharging from the roller table type tunnel kiln so as to obtain high-purity terbium oxide, wherein the purity of the terbium oxide is 99.9%. The first-pass yield is high, and the preparation cost is low.

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 terbium oxide. Background technique [0002] Terbium oxide (Terbium Oxide) belongs to rare earth oxides, chemical formula: Tb 4 o 7 , molecular weight 747.70; density: 7.3g / cm 3 ; Melting point: 2340℃; Properties: brown powder; Physical and chemical properties: insoluble in water and alkali but soluble in acid. [0003] As a main functional material, terbium oxide is used to make metal terbium, magneto-optical glass, phosphor powder, magneto-optic storage materials, chemical additives, etc. [0004] Terbium is a medium-to-heavy rare earth element among the fifteen rare earth elements, and its content in the earth's crust is very low, only 1.1ppm. 1.1-1.2% of the total. The content of terbium in general medium-yttrium and europium-rich materials is 0.6-0.8%. As for the content of terbium in northern my country, whi...

AI Technical Summary

Problems solved by technology

The main disadvantage of this method is that there are many steps. It takes three or three steps only for extraction and separation, and each step needs to use acid and alkali to saponify and back-extract, and there are many steps. The precious terbium element is pressed in each process equipment. The quantity will increase, so the cost of the whole process is also high

It can be seen that although a single pure terbium oxide can be obtained directly through extraction and separation, the process is too complicated, and the more steps in the process, the more factors affecting the final high-purity terbium oxide

[0007] In view of this, the problem of how to find a reasonable balance between simplifying the process and shortening the process steps and obtaining high-purity terbium oxide has long puzzled the industry, and it is expected to be resolved, but in the patent and non-patent literature disclosed so far There is no technical enlightenment that can be used for reference. For this reason, the applicant has made persistent and beneficial explorations, and finally found a solution to the problem, and formed the technical solution that will be introduced below