New aspect of chromite gravity tailings re-processing

Karagedik Chromite Concentrator of the ETI Holding Co., which is located in Fethiye (south Turkey), has been producing chromite concentrate assaying 47–48 % Cr2O3 from chromite ores containing 30–35 % Cr2O3 by gravity separation methods since 1920. The tailings, containing 13–14 % Cr2O3, which had been removed from this plant, were accumulated at stockpiles, amounting to about 1.2 million tons. Generally, at the chromite concentrators of Turkey, such as Karagedik Concentrator, ultra fine size chromite particles (minus 0.038 mm.) were removed as tailings. Likewise, the tailings of the Karagedik concentrator contain a minus 0.038 mm fraction amounting to 42 % of the total. The Cr2O3 content of this size faction is about 23 % with Cr2O3 distribution of 76 %. In order to recover the ultra fine chromite particles from the Karagedik Concentrator tailings, a new process, including Wet High Intensity Magnetic Separation and column flotation, was developed and the Karagedik Research Pilot Plant based on this process was commissioned in 1999. At this plant, final concentrates, assaying 46–48% Cr2O3 are produced and overall plant recoveries are about 60–65%.