Electrostatic separation of muscovite mica from feldspathic pegmatites

• Published in: IEEE transactions on industry applications Vol. 40; no. 2; pp. 422 - 429
• Main Authors: Iuga, A., Cuglesan, I., Samuila, A., Blajan, M., Vadan, D., Dascalescu, L.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2004; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Corona; Dielectrics and electrical insulation; Electric fields; Electrodes; Electrostatics; Grain size; Industry applications; Iron; Ores; Studies; Welding
• ISSN: 0093-9994; 1939-9367
• DOI: 10.1109/TIA.2004.824506

This paper aims at evaluating several electrostatic separation techniques that could be effective for the recovery of mica flakes from pegmatite ores characterized by grain sizes <0.5 mm: 1) triboadhesive separation; 2) dc electric field separation; 3) ac electric field separation; 4) corona field separation using a grounded metallic roll electrode and thermal conditioning; and 5) corona field separation using a grounded metallic roll electrode covered with an insulating layer. The experiments have been carried out on samples containing about 50% mica, 25% feldspar, 15% quartz, 10% iron oxides and hydroxides, as well as iron silicates, with grain sizes ranging between 0.16-0.4 mm. The experimental data confirmed the theoretical predictions: all four separation techniques using high-intensity electric fields improved the grade of muscovite mica concentrate to levels that fulfill the requirements of several industry applications such as welding wire manufacturing. The best results [46.11% SiO/sub 2/, 33.64% Al/sub 2/O/sub 3/, and 11.1% (K/sub 2/O+Na/sub 2/O)] were obtained when performing a three-stage separation using method 5).