Method for removing water in dewatered tail gas during preparation of anhydrous magnesium chloride

　The invention provides a method for removing moisture from dehydrated tail gas in the process of preparing anhydrous magnesium chloride. In this method, magnesium chloride dihydrate or anhydrous calcium chloride is used as an adsorbent. In a hygroscopic reaction bed, a dehydration tail gas is subjected to a contact adsorption reaction to remove moisture in the tail gas and become a dry gas. The moisture content of the treated tail gas of the present invention is 1 to 2%, which can meet the requirements for dehydration of anhydrous magnesium chloride. The treated tail gas can be used as a gas in the dehydration process of anhydrous magnesium chloride; the adsorbent after water absorption can be reused by heating to reduce the cost. The invention is simple and easy to implement, safe in operation, and strong in practicability.