A kind of production method of fine-grained low-chloride rare earth carbonate

Abstract

The invention relates to a production method and device of fine-grained low-chloride rare earth carbonate. The production method is mainly characterized in that rare earth chloride and a carbonate solution are added in a concurrent flow feeding way on a designed special precipitation reaction device, the spatial separation of a reaction zone and a crystallization zone is realized by controlling the feeding speed and discharging speed and controlling the aging time of rare earth carbonate, and thus the double purposes of directly obtaining a fine-grained low-chloride rare earth carbonate product from a hydrochloric acid medium by precipitation and realizing continuous production are achieved. By adopting the production method and device provided by the invention, the fine-grained rare earth carbonate product with the chloride content of less than 50ppm can be directly obtained from the hydrochloric acid medium by using cheap ammonium bicarbonate, the precipitation reaction device has a simple structure, and the continuous production can be realized.

Description

technical field [0001] The invention relates to a production method of fine-grained low-chloride rare earth carbonate, which belongs to the field of rare earth hydrometallurgy and rare earth materials. Background technique [0002] Rare earth carbonate is used as a precursor for the preparation of rare earth phosphors, rare earth polishing powders, rare earth permanent magnet materials, hydrogen storage materials and structural materials, and various quality indicators are the main factors affecting its physical and chemical properties. In addition to the basic requirements for the chemical composition of rare earth products, many rare earth application companies have also put forward new and higher requirements. For example: In recent years, the price instability of rare earth products has forced rare earth application enterprises to reduce the amount of rare earth as much as possible to achieve the purpose of saving costs. The amount of rare earth can be reduced by further...

AI Technical Summary

Problems solved by technology

[0003] The Chinese patent "Ultrasonic-assisted oxalate precipitation to produce low-chloride fine-grained high-purity rare earth compounds" (CN102978399A) invented a method of using oxalic acid and its salts to directly precipitate rare earths to produce low-chloride fine-grained rare earth compounds, but the price of oxalic acid is high Toxicity will pollute the environment, and the solubility of oxalate will affect the recovery rate of rare earths; Chinese patent "Production method of high bulk density fine particle low chloride rare earth carbonates and oxides" (CN 103708525A) is based on the phase between rare earth carbonates Transformation characteristics, using alkali solution to treat rare earth carbonate to prepare fine-grained low chloride basic rare earth carbonate method, the chloride content is above 160ppm

Images