A novel MagLev-based separation approach for heavy metal recycling

Abstract

Separation is crucial for recycling heavy metals, however, most of the reported processes focus on separating metals from non-metals. Here we propose a magnetic levitation (MagLev) configuration to separate heavy metals from metallic mixtures. The novel configuration is able to levitate substances with specific densities over 5.00 g/cm3, while the extant MagLev devices can only handle materials that have specific densities no more than 3.00 g/cm3. We mathematically model the proposed MagLev configuration and apply the approach to separate rare earth metals from fluorescent powders as well as indium contents from indium-tin oxide (ITO)/glass mixtures, mechanically processed liquid crystal displays (LCDs) and ITO powder. The results show that the recovery rates of ITO from ITO/glass mixtures are over 95%, the concentrations of indium in separated LCD shreds are doubled (from 912.0 ppm to 1873.1 ppm), and the purities of separated In2O3 from ITO powder are around 90%. The method is controllable and requires no energy or chemical inputs, and it thereby has tremendous prospects in heavy metal recycling.