Low-grade iron ores are often associated with silica and clay gangue minerals that adversely affect downstream beneficiation processes. In the present study, a novel Pulse Bed Mineral Scrubber (PBMS) developed at CSIR–IMMT was optimized for the beneficiation of low-grade iron ore fines. Detailed physical, chemical, and mineralogical characterization revealed that the ore contains 56.6% Fe, 9.42% SiO2, and 4.72% Al2O3, with hematite, goethite, quartz, and kaolinite as the major mineral phases. A process optimization of the PBMS was carried out using Response Surface Methodology (RSM) based on a Central Composite Rotatable Design (CCRD). Water rate, feed rate, and pulsation frequency were taken as operating variables. The statistical analysis performed indicated that pulsation frequency significantly influenced product quality and separation efficiency. The optimized operating conditions were identified as a feed rate of 600 kg/h, water rate of 19.85 L/min, and pulsation frequency of 94 rpm. Validation experiments were conducted under these conditions, and a clean coarse product assaying 61.11% Fe at a yield of 53.36%, along with a heavy fine fraction containing 60.73% Fe at a yield of 12.51%, were obtained. The process achieved approximately 45% reduction in silica and alumina contents compared with the feed. Mineralogical characterization of the obtained products confirmed the effective enrichment of iron-bearing minerals in the clean coarse and heavy fine fractions. The work demonstrates that PBMS is an efficient, compact scrubbing technology that can clean and classify low-grade iron ore, thus improving the feed quality for subsequent beneficiation operations.
Behera et al. (Sun,) studied this question.