Iron ore beneficiation using roll-type high-intensity electric field separators

This paper aims to demonstrate that high-intensity electric fields can be employed for the separation of artificial magnetite processed from an iron mineral containing siderite FeCO₃ and ankerite (FeCaMg)CO₃. All the tests were carried out on a roll-type laboratory separator (roll diameter: 250 mm; roll speed: 175 r/min), provided with an over-tray heater, to ensure the thermal conditioning of the samples at +120°C, and a system of high-voltage electrodes, consisting of a needle-type corona electrode and either a second corona electrode or a tubular (electrostatic) electrode. The samples were collected from the technological process presently employed for the beneficiation of the iron ore deposit at Teliuc, Romania. The grain size was typically in the 0.09-0.315-mm range. Separation in high-intensity electric field ensured the increase of the Fe content in the samples from about 35% to 55%, for an iron recovery of up to 80%. This paper discusses these results in relation to the mineralogical characteristics of the samples and concludes that electrostatic separation could be employed either as an additional operation in an existing technological process, or as an alternative to the currently employed magnetic separation. Pilot-plant tests are needed prior to industry application