Semi-Smelting Reduction and Magnetic Separation for the Recovery of Iron and Alumina Slag from Iron Rich Bauxite

Abstract

This work presents a semi-smelting reduction and magnetic separation process for the recovery of iron and alumina slag from iron rich bauxite ore. The effect of the process parameters on the recovery rate of iron, maximum particle size of the iron nugget, and the Al2O3 content of the alumina slag was investigated and optimized. The results show that the iron nuggets and alumina slag can be obtained in a short time through a semi-smelting reduction and magnetic separation process. The maximum particle size of iron nugget is about 15 mm, and the recovery rate of the iron and Al2O3 grade of the alumina slag are 96.84 wt % and 43.98 wt %, respectively. The alumina slag consisted mainly of alumina (α-Al2O3), calcium hexaluminate (CaAl12O19), gehlenite (Ca2Al2SiO7), and small amounts of hercynite (FeAl4O7), and metallic iron (M.Fe).

Recent Trends in the Technologies of the Direct Reduction and Smelting Process of Iron Ore/Iron Oxide in the Extraction of Iron and Steelmaking

“…Furthermore, due to the vast utilization capacity of the different iron processing methods in modern-day iron and steel-making technology, it becomes imperative and advantageous to enumerate the basic challenges and limitations peculiar to convectional iron and steel production routes by proferring meaningful solutions and mapping-out holistic future perspectives to issue surrounding extraction process of pure metallic iron. Thus, this study suggests the need to employ a more pragmatic metallurgical extraction approach in the production routes for iron processing with lower production costs and minimal energy requirements [86,87]. This can also be attributed to the ability to utilize other alternative energy sources instead of the use of metallurgical coke as a reductant.…”

Red Mud as a Secondary Resource of Low-Grade Iron: A Global Perspective

“…Zhang et al [144] reported a semi-smelting reduction on an iron rich bauxite ore and magnetic separation process for the recovery of iron and alumina slag under a lower basicity condition. The composition of iron rich bauxite from western Guangxi, China is given in Table 6.…”

Low-temperature thermal conversion of Al-substituted goethite in gibbsitic bauxite for maximum alumina extraction

“…28,29 The addition of reducing agents during the thermal conversion process to induce the conversion of goethite and Al-goethite to magnetite has also been widely reported, with the conversion temperature varying depending on the type of reducing agents. [30][31][32] Processing goethite-rich iron ores using reduction roasting followed by lowintensity magnetic separation can obtain an iron concentrate with a total iron grade of $66.6% and iron recovery of $90.4% at 800 C for 30 min using 10% coal. 33 According to the literature, 34 a good temperature for converting goethite to magnetite through reduction roasting was found to be between 650 C and 700 C in 50%/50% CO/CO 2 mixtures.…”