Anhydrous high-purity rare earth fluoride and preparation method thereof

Abstract

The invention discloses an anhydrous high-purity rare earth fluoride and a preparation method thereof. The anhydrous high-purity rare earth fluoride mainly comprises minim non-rare earth impurity iron (Fe2O3<=1ppm), calcium (CaO<=10ppm), silicon (SiO2<=10ppm), carbon (C<=200ppm), oxygen (O<=200ppm), chloride (Cl<=30ppm), sulfur (S<=10ppm) and the like and has ignition loss not more than 0.5%. The product is mainly applied in the field of electronic and luminescent materials. The preparation method is characterized by pre-removing the non-rare earth impurity by enhancement on the basis of the traditional process and then carrying out conversion in the form of compound fluorinating agents; strictly controlling the feed liquor concentration and acidity, fluorinating agent addition, fluorination temperature and time, etc and obtaining the rare-earth fluoride which is coarse in fluorinated particles, fast in sedimentation and easy to wash and filter; and finally obtaining the anhydrous high-purity rare earth fluoride product through subsequent drying and particle integration.

Description

technical field [0001] The invention belongs to the technical field of solvent precipitation conversion synthesis of rare earth salts, in particular to anhydrous high-purity rare earth fluorides and a preparation method thereof. Background technique [0002] In the early days, rare earth fluorides were mainly used as luminescent agents for arc carbon rods to fill the center of anode carbon rods; in addition, as additives for steel and non-ferrous alloys, they played the role of desulfurization and deoxidation; It is a fluoride system electrolysis used as a molten salt, which forms a molten salt electrolyte with lithium fluoride and barium fluoride to prepare rare earth metals, and is also used as a raw material for the preparation of a single rare earth metal by metallothermal reduction; with the development of science and technology, in recent years The use of rare earth fluorides in the fields of electronic materials, polishing materials and conversion luminescent material...

AI Technical Summary

Problems solved by technology

At present, most manufacturers adopt the wet method. Although the conventional wet method is easy to operate, the precipitated rare earth fluoride is in the form of colloid, which is difficult to filter and wash. It takes a long time to clarify the precipitate, especially the high content of non-rare earth impurities, so it cannot be used directly. In the field of electronics and luminescent materials, it is necessary to provide anhydrous high-purity rare earth fluorides and their preparation methods

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