Synthesis and application of hematite nanoparticles for acid mine drainage treatment

Abstract

In this paper, the synthesis of pure hematite nanoparticles, magnetic properties and its removal capacity of metal cations from acid mine drainage are well described. Initially, mixtures of iron oxide nanoparticles were synthesised using hydrated ferric chloride and ferrous sulphate salt solution by co-precipitation method and converted to hematite via calcination at 500 °C. The synthesised hematite nanoparticles have shown superparamagnetic character with saturation magnetisation of 5.6 emu g−1. Treatment of partially aerated acid mine drainage in the presence of 0.85 g L−1 of synthesised hematite resulted in complete removal of Al, Mg, Mn and Fe while for Zn and Ni over 80% and Ca and Na in between 47 and 72% removals. The sludge generated from the treated acid mine drainage was also characterised by relevant analytical instruments. Overall, the non-toxicity, stability and high metal removal capacity of hematite nanoparticles is promising for the future application in large-scale acid mine drainage treatment.