Physicochemical studies on the thermal hydrolysis of aluminum chloride

Abstract

A thermohydrolysis process is considered for aluminum chloride hexahydrate as one of repartition stages for a hydrochloric acid technology of alumina production from Russian high-silicon raw materials. A physicochemical study is performed for the burning of AlCl₃ · 6H₂O, and the temperature ranges for the removal of water and chloride ions are determined. It is shown that chloride ion is released mainly as HCl. The effect of burning temperature on the phase composition and the basic physical properties of the alumina powder (specific surface area, porosity, and average particle size) is studied. The results of optical and electron microscopy showed that the alumina particles retain the hexagonal structure of the source of aluminum chloride hexahydrate. It is established that ultrasonic treatment affects the dispersion level of the aluminum oxide powder. The data obtained allow one to produce metallurgical alumina of “sandy” type which can be used to prepare aluminum metal by means of electrolysis.