Method and device for preparing anhydrous rare earth chloride through gas phase method

Abstract

The invention provides a method for preparing anhydrous rare earth chloride through a gas phase method. According to the method, hydrogen chloride gas is directly used to chlorinate a rare earth oxide serving as a raw material to prepare anhydrous rare earth chloride. The method comprises the following steps: putting the rare earth oxide in a chlorination furnace and heating to 350-650 DEG C; introducing hydrogen chloride gas into the chlorination furnace to chlorinate the rare earth oxide; holding the temperature for 20-35h then stopping, thus obtaining the chlorinated anhydrous rare earth chloride; in the chlorination process, absorbing the hydrogen chloride tail gas (discharged by the chlorination furnace) by a lime solution through an acid mist absorption device and emptying the hydrogen chloride tail gas. When used for preparing anhydrous rare earth chloride, the method is capable of inhibiting generation of chlorinated rare earth oxides; and the purity of the prepared anhydrous rare earth chloride product is higher than 98.00% and the yield of rear earth is higher than 99.5%.

Description

technical field [0001] The invention relates to a method and a device for preparing anhydrous rare earth chloride by directly chlorinating and oxidizing rare earth in a gas phase method, and belongs to the technical field of rare earth metallurgy. Background technique [0002] Rare earth materials are indispensable materials in high-tech fields in the world today. my country's rare earth production and application rank first in the world. With the expansion of the application field of rare earth materials, the demand for anhydrous rare earth chloride in metallurgy, petrochemical industry, glass, textile, and material preparation is increasing, and the consumption is increasing year by year. [0003] At present, the technology used for large-scale production of anhydrous rare earth chloride is mainly based on the hydrated chloride dehydration method. The process is: the rare earth oxide is decomposed with hydrochloric acid to obtain a rare earth chloride solution; the rare ea...

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Problems solved by technology

[0004] Among these preparation methods, the dehydration method of hydrated chloride is used to prepare anhydrous rare earth chloride. It is necessary to dissolve rare earth with hydrochloric acid to form hydrated chloride and then dehydrate. The process is long, energy consumption is large, vacuum equipment is required, and it is difficult to avoid the occurrence of Hydrolysis, the prepared product has high water content and also contains oxychloride impurities; dry chlorination of ammonium chloride to prepare anhydrous rare earth chloride requires excessive ammonium chloride to achieve better results, and the volatilization of ammonia is serious , causing environmental pollution

Chemical Vapor Transport and CCl 4 The chlorination method can be used to prepare a small amount of high-purity reagents, but the technical conditions of the preparation process are relatively high, and it is difficult to realize the batch preparation of anhydrous rare earth chlorides

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