Preparation method of low-fluorine high-purity tantalum pentoxide optical coating material

Abstract

The invention discloses a preparation method of a low-fluorine high-purity tantalum pentoxide optical coating material, and particularly relates to the technical field of tantalum metal oxide preparation, which comprises the following steps: dissolving metal tantalum in a mixed acid of hydrofluoric acid and nitric acid, extracting and purifying to obtain a high-purity tantalum liquid, introducingthe high-purity tantalum liquid into a neutralization precipitation tank, adding liquid ammonia into the high-purity tantalum liquid at the same time, introducing a solution containing tantalum hydroxide precipitate into a filter press after the tantalum hydroxide precipitate appears, adding ammonia-containing hot pure water at the same time, then obtaining tantalum hydroxide, and then repeatedlyadding tantalum hydroxide into the filtering process for multiple times. According to the method, tantalum pentoxide is heated through electron beams, the purpose of heating calcination can be achieved without high temperature, grain distribution is uniform, the crystal system structure is more ideal, meanwhile, ammonia-containing hot pure water is repeatedly used for assisting the filtering process, it is guaranteed that the effect of removing fluorine in the tantalum hydroxide solution is more ideal and sufficient, and the fluorine content in the product is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of preparation of tantalum metal oxides, more specifically, the invention relates to a preparation method of a low-fluorine and high-purity tantalum pentoxide optical coating material. Background technique [0002] At present, the traditional high-purity tantalum pentoxide is produced by liquid-liquid extraction and separation of tantalum and niobium. First, the tantalum liquid is poured into the neutralization precipitation tank, and NH3 gas is introduced under stirring to make the solution pH =8-9, a tantalum hydroxide precipitate is generated, which is then passed through a filter press or vacuum filtered. Then put the tantalum hydroxide back into the decomposition tank, add hydrofluoric acid and sulfuric acid to dissolve, and carry out secondary extraction with organic matter to obtain high-purity tantalum liquid, and the high-purity tantalum liquid is neutralized with purified ammonia water to obtain hi...

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Problems solved by technology

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for preparing a low-fluorine high-purity tantalum pentoxide optical coating material. The technical problem to be solved by the present invention is: the removal effect of fluorine in the preparation of existing tantalum pentoxide It is not ideal, and at the same time, the simple sintering process causes the tantalum pentoxide to be a mixed crystal of the triclinic system and the tetragonal system, resulting in an unsatisfactory crystallinity of the tantalum pentoxide

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