Surface Barrier-Assisted Reduction of Red Mud for Iron Phase Separation and Potential Reinforcement in Lightweight Automotive Materials

Abstrak

Red mud is a by-product of industry that has high levels of iron, aluminum, and silicon oxides. It can be used to strengthen aluminum matrix composites. However, its uneven phase distribution and the tendency of particles to clump limit its effectiveness. This study looks at a coal gangue surface barrier to improve red mud reduction and separate iron phases more effectively. We tested three methods: untreated red mud, magnetic pre-treatment, and barrier-assisted reduction. The results show that traditional reduction requires temperatures above 800 °C because of contamination. In contrast, the barrier-assisted method achieves effective reduction at around 550 °C. This finding aligns with thermodynamic predictions. XRF and XRD analyses confirm better separation. Magnetite is the main component in the magnetic fraction, while Al–Si-rich phases, such as corundum and quartz, are more concentrated in the non-magnetic fraction. Notably, the barrier-assisted reduction approach achieved an iron recovery of 99.04%, markedly higher than the 71.37% reported in earlier studies. As a result, the coal gangue barrier enhances its potential as reinforcement in lightweight automobile composites by improving reduction efficiency and producing cleaner Al–Si-rich material.

Kata kunci

• Red Mud
• Surface barrier reduction
• Coal gangue
• Magnetic separation
• Phase transformation