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

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%.