Method for preparing rare earth fluoride

Abstract

The invention provides a method for preparing rare earth fluoride, which is formed by the following: a. a step of preparing acetic acid rare earth aqueous solution, which is to dissolve rare earth oxide in diluted acetic acid with the concentration of between 20 and 40 percent, the molar ratio of the rare earth oxide to acetic acid is between 1 to 6 and 8, so as to form the acetic acid rare earth aqueous solution; b. a step of preparing an ammonium fluoride aqueous solution, which is to dissolve ammonium fluoride with 6 to 6.5 times the molar weight of the rare earth oxide into deionized water, so as to form the ammonium fluoride aqueous solution; c. a step of preparing rare earth fluoride, which is to mix the acetic acid rare earth aqueous solution in the step a and the ammonium fluoride aqueous solution in the step b for reaction and to precipitate the rare earth fluoride; and d. a step of drying and sintering, which is to drying the rare earth fluoride precipitated in the step c at a temperature between 70 and 100 DEG C and then to sinter the rare earth fluoride in a sintering furnace at a temperature between 250 and 350 DEG C for 5 to 10 hours. The method does not corrode equipment or pollute environment, is simple in process, low in energy consumption, convenient for industrial production and high in the purity of the prepared products.

Description

technical field [0001] The invention relates to a method for preparing rare earth fluoride. Background technique [0002] Rare earth fluoride is an important chemical raw material. It is an important raw material for producing a single rare earth metal by metallothermic reduction. It can be used as a luminescence enhancer for carbon arc rods, a solid lubricating material, an additive for steel and non-ferrous alloys, and a glass additive. , can also be used as an electrolyte for mixed rare earth metals. In recent years, new materials such as fluoride optical fiber and phosphor powder for infrared region have been developed by using refined rare earth fluoride. At the same time, with the development and application of new rare earth functional materials such as permanent magnet materials, hydrogen storage alloys, and magneto-optical storage, the application of rare earth fluorides in the chemical industry will further increase. [0003] The existing production of rare earth...

AI Technical Summary

Problems solved by technology

The disadvantages of dry preparation of rare earth fluoride are: complex equipment, severe corrosion of equipment by hydrogen fluoride gas at high temperatures of 600-900 °C, and difficulties in the protection of hydrogen fluoride gas and tail gas treatment

Its disadvantage is that although its processing temperature is low, due to the use of hydrochloric acid and hydrofluoric acid in the production process, the residual hydrochloric acid and hydrofluoric acid are mixed with nickel or stainless steel during the low-temperature drying and dehydration process of rare earth fluorides. The trough reaction causes non-rare earth impurities such as O, S, Fe, Ni, C, Si to increase in the rare earth fluoride made; meanwhile, other rare earth-containing compounds such as rare earth oxychloride ( ReOCl) and rare earth oxyfluorine (ReOF, Re is rare earth elements such as yttrium, lanthanum, praseodymium, neodymium, etc.)

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