1Department of Mining Engineering, Research and Science Branch, Islamic Azad University, Tehran, I.R. IRAN
2Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, I.R. IRAN
Different samples have been prepared from different products in Chadormalu iron ore concentrator plant: Low intensity magnetite separators concentrate (magnetite concentrate), reverse flotation tail (final hematite concentrate), flotation concentrate (apatite concentrate), final tail (L.I.M.S. tail + reverse flotation concentrate+ apatite flotation tail). The samples were used for rare earth elements (REEs) distribution and origin studies. The assay of REEs was determined by ICP-MS spectrometry. The amount of total (light and heavy) REEs were 9631, 291, 199, 2236 ppm and the distributions were 19.3, 3.6, 10.1, 67 % in flotation concentrate (apatite concentrate), reverse flotation tail (hematite concentrate), magnetite concentrate and total tail respectively. About 19.3 % of total REEs were distributed in apatite concentrate with an assay of 9631 ppm. Therefore, further studies have been conducted on this product. According to the Xray studies the minerals of fluorapatite, ankerite and calcite are the main mineral phases in apatite concentrate which the apatite is dominant among them. The scanning electron microscopy studies were shown that the high amount of REEs distributed on fluorapatite mineral. The results have clearly shown that the apatite concentrate that is a by product of iron dressing in Chadormalu plant, with a low economical value and left without any further treatment, can be used as a significant source of REEs. According to this characterization studies, the recovery of a mixed rare earth oxide from fluorapatite is possible either with the treatment of liquors from the total dissolution of the ore in nitric acid or with the proposed treatment of the phosphogypsum by-product from the conventional sulphuric acid route and the recovery of rare earth oxides from phosphoric acid sludges that the detailed flowsheet needs further extraction work.
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