Resumo

BADA, S.O; FALCON, L.M.; FALCON, R.M.S.  e  BERGMANN, C.P.. Feasibility study on triboelectrostatic concentration of < 105 µm phosphate ore. J. S. Afr. Inst. Min. Metall. [online]. 2012, vol.112, n.5, pp.341-345. ISSN 2411-9717.

Fine phosphate feed is considered to be slime and normally disposed of as a discard in settling ponds or dumped as landfill. The purpose of this research was to establish whether commercially acceptable qualities and yields could be obtained from this material using dry separation methods. The results obtained from the electrostatic separation of <105 µm phosphate ore are presented. An existing separator was upgraded in order to improve on product and flotation concentrate recovery, to test different mineral, and to reduce particle residence time between the charging chamber and the separating zone of the separator. The operating conditions were varied according to the charges imparted to the particles in the electric field, and according to other device parameters. Parameters such as splitter position, charge reversal, rotation speed, charging voltage and separating voltage. The <105 µm phosphate feed was concentrated under both triboelectrification and inductive charging. The use of inductive charging and charge reversal resulted in a significant increase in grade for <105 µm phosphate feed, with the P₂O₅ grade increasing from about 12 per cent to 20.50 per cent, and a recovery of 26.30 per cent under a single stage of separation. It was found that better separation was achieved at rotation speed of 6000 r/min, -8 kV charging voltage, and 25 kV separating voltage.

Palavras-chave : dry beneficiation; electrostatic separation; particle charging; phosphate; triboelectrostatic.

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