Preparation method of anhydrous cerium chloride

Abstract

The invention provides a preparation method of anhydrous cesium chloride. The preparation method is characterized in that cerium oxide is taken as a raw material, reaction is conducted by using ammonium chloride solid, then dried hydrogen chloride gas enters, heating is conducted until the reaction is completed, and products are dried to obtain anhydrous cesium chloride. By the combined use of theammonium chloride and the hydrogen chloride gas, and by the combination and the proportioning of the using amount of reactants, the synergistic effect of the ammonium chloride and the hydrogen chloride is achieved to adjust the position relationship of each reactant, to make the reaction more complete, the yield of the reaction product is high, drying is conducted under an inert atmosphere by reducing pressure to prevent the occurrence of redox side reaction, improve the product purity, and the preparation method is safe and effective, and the products are pure.

Description

technical field [0001] The invention belongs to the field of rare earth material preparation, and mainly relates to a preparation method of anhydrous rare earth samarium chloride. Background technique [0002] Rare earth elements are the general term for group IIIB yttrium and lanthanide elements in the periodic table. They are active metals with very similar properties. They have important biological activity and pharmacological effects. They can be used in two salt systems of chloride and fluoride. Anhydrous rare earth chlorides are basic reagents for the preparation of rare earth-containing organic compounds. [0003] At present, the method for preparing anhydrous rare earth chloride can be prepared by tetrahydrofuran complex method, through metal exchange reaction in THF solution to prepare anhydrous rare earth chloride, starting from the rare earth metal and reacting with mercuric chloride to prepare THF of anhydrous rare earth chloride Complexes, but the reaction invo...

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Problems solved by technology

[0003] At present, the method for preparing anhydrous rare earth chloride can be prepared by tetrahydrofuran complex method through metal exchange reaction in THF solution to prepare anhydrous rare earth chloride, starting from the rare earth metal and reacting with mercuric chloride to prepare THF of anhydrous rare earth chloride Complexes, but the reaction involves toxic and harmful substances, which is not conducive to industrial production; the ammonium chloride sublimation method converts rare earth oxides into rare earth chlorides, but it is difficult to obtain high-purity anhydrous Rare earth chloride: Anhydrous rare earth chloride prepared by chlorination of rare earth oxides is prone to residual impurities and water-insoluble substances. The chlorination temperature requires high requirements and the process is complicated.

The water absorption of samarium chloride is very strong, and it is prone to redox reaction to form samarium oxychloride, which affects industrial application

[0004] The new preparation method of anhydrous rare earth chlorides prepares anhydrous rare earth chlorides from rare earth oxides (Ding Zongbiao, Cheng Kejun, Chemical Journal, 1997, 55:1004-1008) discloses a method using trimethylchlorosilane as a scavenger The method of preparing anhydrous rare earth chloride by aqueous solution is carried out at room temperature and in THF under a dry nitrogen atmosphere. Both methanol and trimethylchlorosilane are excessive. The reaction is stopped after 15 hours, and a fine crystalline white solid is precipitated. Flow down and heat to reflux for 3 hours, remove volatile substances under reduced pressure, wash the product with dry n-pentane, and dry it in vacuum to obtain a white solid which is the target product. Although the method has mild conditions, the procedure is complicated and involves toxic and harmful reagents, so it is not suitable for industrial production.

CN107827140A discloses a method for preparing anhydrous rare earth chlorides. The heptahydrate rare earth chlorides are divided into three stages for fluidized dehydration, and the dehydration is carried out under a hydrogen chloride gas atmosphere. The dehydration method needs to undergo three times of fluidized dehydration, and strict temperature control is required. and wind speed, not suitable for industrial production

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