Sustainable Mining and Metallurgy

The content of iron minerals (alumino goethite and hematite) in the red mud dissolved by the Bayer method reaches more than 60%, which can replace high iron ore as an auxiliary material to prepare sintering clinker and improve the net dissolution rate of alumina. In this paper, based on the theory, the laboratory experiment was carried out to analyze the change of sinter grade, clinker chemical composition, clinker dissolution index and clinker dissolution and sedimentation performance after red mud ore blending, and compared with the index of high iron ore blending mode. The experimental results show that the alumina content and aluminum-silicon ratio (A/S) of the clinker are reduced by using the low-temperature Bayer process red mud to prepare the sintering clinker, but the standard dissolution rates of alumina and sodium oxide are basically the same. The absorbance of the coarse liquid after the clinker dissolution is reduced, and the sedimentation and compression properties of the red mud produced by the clinker dissolution are comparable. Therefore, it is feasible to use low-temperature Bayer red mud to prepare sintering clinker. After adopting red mud ore blending, by adjusting the clinker alkali ratio and calcium ratio, correcting the [F/A] control range, adjusting the fixed carbon content of raw slurry and other measures in the actual production site, the optimization and improvement of the operation index of alumina production by sintering method is achieved, which not only reduces the ore cost of sintering system, but also realizes the reuse of red mud. It is of certain significance to improve the net dissolution rate of alumina in the production of alumina by sintering method of low grade bauxite in China.