Process for thermal decomposition of aluminum chloride hexahydrate

A process for the thermal decomposition of aluminum chloride hexahydrate into anhydrous Al.sub.2 O.sub.3 comprising:

• (1) continuously introducing the aluminum chloride hexahydrate into a turbulent reaction zone;
• (2) continuously introducing an amount of gas below a gas distributor in the turbulent reaction zone to maintain the solid material above the distributor in a fluidized state with a decrease in the concentration of solid material from the bottom to the top of said turbulent reaction zone;
• (2') continuously introducing a secondary gas into the turbulent reaction zone at a level above the gas distributor;
• (3) continuously extracting the solid material with the gas from the upper portion of the turbulent reaction zone;
• (4) continuously separating the solid material from the gas extracted from the upper portion of the turbulent reaction zone;
• (5) continuously feeding the separated solid material to a residence reaction zone which is operatively connected and maintained separate and apart from the turbulent reaction zone;
• (6) continuously introducing gases into the residence reaction zone in an amount sufficient to maintain the solid material in a fluidized state;
• (7) continuously recycling a portion of the solid material from the residence reaction zone downwardly to an intermediate portion of the turbulent reaction zone;
• (8) extracting a portion of the solid material from the residence zone as product;
• and
• (9) maintaining the suspension density in the turbulent reaction zone in the area between the gas distributor and the secondary gas inlet at an average of 20-300 kg/m.sup.3 inlet to a value between 1 and 20 kg/m.sup.2 and maintaining the suspension density in the reaction zone at an average greater than 600 kg/m.sup.3.