Development of Beneficiation Process for High Alumina Iron Ores of Bellary-Hospet Region

Abstract

JSW Steel is operating a 4.2 Mtpa capacity Pellet Plant to produce iron oxide pellets from the iron ore fines avail-able in the surrounding Bellary-Hospet region of southern India. Iron ore fines which get generated during mining are soft and rich in alumina with high amount of ultra fines. These characteristics of iron ore fines make it difficult to produce good grade pellets for use in COREX iron making units. Apart from this, high alumina in the pellets increases the slag volume in Corex, which demands additional heat energy, resulting in increased fuel rate. Hence, it was decided to set up a beneficiation plant to reduce the alumina content of the ore fines. Iron ore fines from several sources available in the Bellary- Hospet region were evaluated for their suitability for beneficiation as each source differs in chemistry, particle size distribution and washability characteris-tics. A technique called "Sizewise Washability Technique" was developed to study the washability characteristics of the ore fines to determine the extent of alumina reduction on washing and corresponding yield of concentrate. Iron ore fines from 13 sources were tested and were classified as Preferable, Tolerable and Not- Washable depending on their suitability for beneficiation. Mineralogical studies were also undertaken to understand the liberation characterist-ics of gangue minerals to achieve proper alumina reduction during beneficiation.