Red Mud Processing
Red mud processing represents a distinct and large-scale segment of technogenic waste utilization, generated as a by-product of alumina production. Over decades of operation, alumina plants accumulate millions to tens of millions of tonnes of red mud, occupying vast areas and causing long-term contamination of soil and groundwater. GRAVICON has developed technological solutions for integrated red mud recycling, enabling separation into silica sand (SiO₂), iron ore concentrate (IOC), non-ferrous metals (vanadium, titanium), and rare earth elements (REEs). The establishment of a full-cycle processing facility—from laboratory testing of a specific tailings pond (each deposit has a unique mineralogical composition), process adaptation, engineering design, installation, and commissioning—typically requires 10–12 months, with an expected investment payback period of up to 1 year. Project cost depends on the target product slate: REE oxides obtained at early processing stages are already marketable products, while deeper processing to chemically pure REEs significantly affects both CAPEX and overall project economics and can be determined only after customer technical requirements and site-specific test work.Chemical analysis of a representative red mud pond (data from an industrial site outside Ukraine) demonstrates the high content of valuable components: Fe₂O₃ – 39.21%, Al₂O₃ – 16.31%, SiO₂ – 15.68%, TiO₂ – 3.99%, V₂O₅ – 0.18%, along with Na₂O, CaO, MnO, and MgO. Of particular interest are rare earth elements, including Sc – 60 ppm, Y – 132 ppm, Ce – 390 ppm, La – 250 ppm, Nd – 200 ppm, Gd – 150 ppm, Th – 70 ppm, and Ga – 25 ppm, with scandium oxide being especially valuable due to its high market price and demand in high-strength aluminum alloys and LED lighting. Based on 2015 market prices, the recoverable value per tonne of red mud reaches approximately USD 274.40, comprising USD 27.40 from iron ore concentrate (0.392 t at USD 70/t), USD 180.00 from scandium oxide (60 g at USD 3/g), USD 7.00 from thorium oxide (70 g at USD 0.1/g), USD 35.00 from ferrovanadium (5 kg at USD 7/kg), and USD 25.00 from titanium compounds (25 kg at USD 1/kg). With a processing cost of USD 40–50 per tonne, net profit approaches USD 200 per tonne, which, given the scale of red mud deposits, translates into hundreds of millions of dollars in potential profit, combined with a direct and measurable environmental remediation effect.