[Nayak*, 4.(8): August, 2015] ISSN: 2277-9655 (I2OR), Publication Impact Factor: 3.785 http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [228] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY PER-CONCENTRATION OF IRON ORE SLIME IN MAGNETIC SEPARATOR Dr. Nirlipta Nayak*, Dr. B. K. Pal * Asst. Professor, Department of Petroleum Engineering, UPES, Dehradun Professor, Dept. of Mining Engg. NIT, Rourkela ABSTRACT Indian iron ore is generally friable in nature that results in generation of significant quantity of fines (around 35%) during mining and processing in the country. The ratio of lumps to fines produced in the country is 2:3. During washing and sizing of the ore, slimes with less than 0.21 mm size are generated and discarded into the tailing pond. It is estimated that around 10 million tons of slimes are being generated in every year during the processing of hematite ore and lost as tailings containing around 48-62% of Fe. The slime sample collected from Barsua assaying 54% Fe, 8.3% SiO2 & 11.08% Al2O3 was studied for pre concentration of iron values adopting gravity techniques followed by magnetic separation. The results indicated that Magnetic separation is a better pre concentration technique compared to gravity. KEYWORDS: Magnetic separation, slime, pre-concentration, tailing. INTRODUCTION Globally, the Iron ore deposits are closely associated with schist belts, gneisses and granulite terrain of Archaean age. In India, the Iron ore deposits are observed as Banded Hematite Quartzite (BHQ), Banded Hematite Jasper (BHJ) and Banded Magnetite Quartzite (BMQ) in parts of Jharkhand, Karnataka, Chhattisgarh, Maharashtra, Orissa and Tamil Nadu states [5]. The friable nature of Indian iron ore causes lots of fine generation during mining & subsequent stages. These fines/ slimes however can’t be used for iron making (blast furnace/ direct reduced iron (DRI) units. In order to produce 1 ton of lump ore, about 1.5 ton fines are [8&2] generated of which only 0.5 ton are utilized. The rest is either dumped as stocks at the mine or permanently lost due to lack of proper beneficiation facilities. These fines could be put to use in the domestic iron & steel industry after suitable beneficiation followed by agglomeration. However, the popularity of these routes is yet to gear up/ pick up the momentum in Indian iron and steel industry. The slimes are ideal for generating the material for pelletization. They can also be used for preparation of sinter feed after microballing. STUDY AREA The study area comes under Joda-Koira Basin (JKB) and forms a small, shallow but highly rich in Iron and Manganese ore basin that forms a ‘U’-shaped exposure of Banded Iron Formation (BIF), northern part which comes under Jharkhand State. While the eastern limb of the ‘Horse-shoe’ is isoclinally [1]folded with dip westward, the rest of the basin have open-folds of three generations i.e. with early E-W, NNE-SSW and later E-W axial planes. Occasional conjugate folds occur at different parts of the basin. The combine leasehold (ML-130) of Barsua-Taldih-Kalta is situated in the classic iron bearing formations of Orissa. The regional geological set up constitutes part of the Precambrian meta- sedimentary sequence known as Iron Ore Series. METHODOLOGY Sieving of iron ore slime sample was carried out using the Vibratory Laboratory Sieve Shaker. For the separation of 200 micron particles micro-precision sieves were used. It is seen from the size measurement that the slime is extremely fine in nature. Substantial amount of the slime is below 50μm Detailed characterization of Barsua iron ore slime revealed that most of the alumina and silica is concentrated in the fraction less than 20 m size. Therefore, it is imperative that a desliming operation to remove the ultrafine fraction would improve the grade. Hence, a beneficiation scheme was chosen involving classification followed by tabling and WHIMS. The results of the unit operations are carried out in these slimes discussed in the following section.