An investigation into processing fine magnetite using a magnetic hydrocyclone

As a consequence of fine grinding in the mineral processing industry, fine material containing quantities of valuable metal is being lost to tailing dams, wastewater and mine drainage. The processing of ultrafine particles has always been a challenge in the mining industry, thus typically, fine components are often considered waste during mineral processing. In addition, magnetic adsorbents are also being investigated as a method of processing wastewater, leading to the need for methods of recovering fine material post adsorption. A method of fines recovery, using a magnetic hydrocyclone to increase ultrafine and fine (−38 µm) material recovery from slurry was investigated in this paper. The attached permanent (Nd-Fe-B) magnet concentrated magnetite particles to the underflow and increased recovery by 15.4%, 5.6% and 2.0% on average for ultrafine (<5 µm) magnetite and two size distributions of fine magnetite (<38 µm), respectively, when compared to a conventional hydrocyclone.