Method for recovery of the constituent components of laterites

A process for separating aluminum, iron, titanium, and magnesium from a laterite comprising:

• digesting the laterite in sulfuric acid to produce a first solution comprising aluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate;
• passing the first solution over metallic iron to reduce the ferric sulfate to ferrous sulfate and produce a second solution;
• adding ammonia to the second solution to precipitate hydrated titania from the titanyl sulfate;
• filtering the second solution to remove the hydrated titania and produce a third solution;
• adding ammonium sulfate to the third solution to form a fourth solution comprising ferrous ammonium sulfate and ammonium aluminum sulfate;
• crystallizing ammonium aluminum sulfate from the fourth solution;
• dissolving the crystallized ammonium aluminum sulfate to form a fifth solution;
• adding ammonium bicarbonate to the fifth solution to precipitate basic ammonium aluminum carbonate;
• recovering the basic ammonium aluminum carbonate;
• calcining the recovered basic ammonium aluminum carbonate for a time and at a temperature sufficient to produce alumina, ammonia, and carbon dioxide;
• adding ammonia or ammonium sulfate to the fourth solution to adjust to equimolar conditions to form a sixth solution;
• adding oxalic acid to the sixth solution to form insoluble ferrous oxalate;
• filtering the fifth solution to remove the ferrous oxalate and produce a seventh solution;
• adding oxalic acid to the seventh solution to precipitate magnesium oxalate;
• recovering magnesium oxalate from the seventh solution;
• heating the magnesium oxalate to form magnesium oxide;
• heating the ferrous oxalate to produce ferrous oxide and carbon monoxide;
• and,
• reducing the ferrous oxide to metallic iron.