Red mud recycling by Fe and Al recovery through the hydrometallurgy method: a collaborative strategy for aluminum and...

In this work, a collaborative strategy for the aluminum and iron industry based on red mud recycling through the hydrometallurgy method was proposed. In this method, Fe³⁺ and Al³⁺ were firstly separated from the red mud by using H₂SO₄ as a leaching agent, which was by-produced from the sintering process of an iron and steel industry. Multiple influence factors on the leaching process were investigated, with the H₂SO₄ addition amount showing the strongest influence on the leaching rates of Al and Fe. The main components of the filter residue were CaSO₄, TiO₂, and SiO₂, which could be reused as additives in the building materials. Subsequently, the final Fe recovery product was obtained through the co-precipitation, Fe/Al separation, and Fe(OH)₃ calcination. In the final product, the content of Fe₂O₃ reached 82.87%, and the iron grade was 58.01%, meeting the requirement being raw materials for sinter production.