Method for aluminum-enhanced dealkalization of red mud and separation and recovery of aluminum and iron

A method for aluminum-enhanced dealkalization of red mud and separation and recovery of aluminum and iron, comprising the following steps:

• S1:
• grinding red mud and dissolving the red mud in slurry liquid, wherein the slurry liquid is water and/or alkaline leachate obtained after filtering;
• uniformly stirring the mixture to obtain red mud slurry;
• introducing SO2 and O2 for aeration oxidation to obtain a red mud mixture;
• and filtering the red mud mixture to obtain dealkalized red mud and acidic leachate;
• and
• S2:
• adjusting pH of the acidic leachate obtained by filtering to a strongly alkaline level to obtain alkaline leachate;
• filtering the alkaline leachate to obtain alkaline leachate after filtering and filter residue;
• drying and sintering the filter residue, washing an obtained product with water, and conducting drying to recover Fe2O3;
• returning ⅕-½ of the alkaline leachate after filtering to step (1) as the slurry liquid;
• and adjusting pH of the remaining alkaline leachate after filtering to a weakly acidic level, and conducting filtering to separate and recover Al(OH)3.