Method for utilizing tail gas of fluidized bed in dry production of aluminum fluoride and equipment

The invention discloses a method for utilizing the tail gas of a fluidized bed in the dry production of aluminum fluoride. The method comprises the following steps: a, screening, namely removing impurities from wet aluminium hydroxide with the moisture content of about 2-8% through a screening device and transmitting into a stock bin; b, reacting and drying, namely transmitting high temperature superheated steam escaped from the top of the fluidized bed to a disc reactor and transmitting the screened aluminium hydroxide to a feeding hole in the top of the disc reactor, wherein the high temperature superheated steam rises from the bottom step by step after entering the disc reactor and the aluminium hydroxide falls under the action of a harrow layer by layer after entering the disc reactor, and in the process, the aluminium hydroxide is in direct contact with the high temperature superheated steam, reacted and dried; and after the reaction and the drying, discharging the aluminium hydroxide with the moisture content of about 0.1% from the bottom of the disc reactor and transmitting to the fluidized bed, discharging the superheated steam with the hydrogen fluoride content of below 1% from the top of the disc reactor and transmitting to a cyclone separator to carry out subsequent dedusting and cooling.