Title Ore Beneficiation Plant 2 - Class Notes ✅

1. Raw Material Handling & Blending  Iron ore is received at the plant via conveyors and local trippers.  Different ore types (possibly from multiple sources or countries) are blended in the Raw Material Handling System (RMHS) to achieve a target grade, such as Fe 55%.  The blending process ensures consistent feed quality to the beneficiation plant, which is crucial when different ores have varying properties. 2. Storage and Feeding  After blending, ore is stored in silos. Silos are used to maintain a frequent and regulated material flow and to buffer the process from upstream supply variations.  The ore is withdrawn from the silo using belt feeders, which ensure continuous, controlled discharge for downstream processing.  Typical silo capacity may be around 500 tons. 3. Wet Screening  The material from the silo passes over conveyor CV01 and is fed to a wet screening station.  Wet screening uses water sprays to wash and separate particles by size, removing fines and clay, and preparing the ore for subsequent classification.[1] 4. Primary Classification & Crushing  The screened ore is separated: o Fines (minus 3 mm) move to the classifier. o Oversize (+3 mm) material is sent to the crusher for size reduction.  The primary classifier further sorts fine particles, usually based on hydrocyclone or settling tank designs. 5. Secondary Processing – Grinding and Additional Classification  Very fine fractions (less than 150 microns) are sent to linear screens or other classifiers.  The coarser fractions may go through scrubbers that use agitation and water to further remove impurities and liberate iron ore from alumina, silica, and magnesium compounds. 6. Spiral Gravity Separation  The classified material is subjected to spiral gravity separation, where heavier iron-rich particles separate from lighter waste (gangue) minerals through centrifugal action and fluid density differences. This yields three products: concentrate (iron-rich), middlings, and tailings.[1]  Multiple spirals or stages may be used to optimize the recovery of iron and quality of concentrate.
7. Magnetic Separation  A High-Gradient Magnetic Separator (HGMS) or similar magnetic equipment removes any remaining iron from the tailings stream and upgrades the concentrate by attracting magnetic iron (magnetite, hematite) and leaving non-magnetic waste behind.  These separators are mechanical systems with high-strength magnets and coils, not electrical systems.[1] 8. Dewatering and Product Handling  The final iron concentrate is dewatered using vibrating (dewatering) screens to remove excess water.  Dewatered product is sized—plus 150 microns and minus 3 mm fractions become the sinter feed or go to pelletization. 9. Downstream Use  The plant produces high-grade iron ore concentrate suitable for use in sinter plants, pellet plants, or direct shipping, upgrading low-grade ore to higher grade. 10. System Automation and Control  The plant is typically divided into models or modules (Model 1, Model 2, etc.), each operating with a series of cyclones (for example, 64 cyclones per module) for classification. Each cyclone separates lighter and heavier particles based on density using pressure (often around 1.1 bar).  Cyclones and classifiers can be monitored via distributed control systems, with feedback loops to adjust pressure, feed rate, and wash water for optimal separation.[1] Key Terms Defined:  Silo: Buffer storage, maintains steady flow.  Belt Feeder: Mechanical device to regulate material flow from storage.  Wet Screen: Uses water spray to help size separation and wash ore.  Classifier/Linear Screen: Separates finely sized particles (primary and secondary stages).  Scrubber: Removes clays/impurities through agitation.  Spiral Separator: Gravity-based separation for mineral density differences.  Cyclone: Uses centrifugal force/pressure for fine particle classification.  HGMS (High-Gradient Magnetic Separator): Extracts magnetic iron minerals from the ore.  Dewatering Screens: Vibratory screens to remove water from final product. Relevant Process Flow Overview (condensed and clarified as per actual industry practice): 1. Ore blending and storage (RMHS)
2. Silo buffering & belt-feeder controlled discharge 3. Wet screening (removal of fines, washing) 4. Crushing of oversize; fines go to classifiers 5. Multiple classification stages (hydrocyclones, linear screens) 6. Scrubbing for impurity removal 7. Spiral gravity concentration 8. Magnetic separation 9. Dewatering of concentrate 10. Final product dispatch to sinter/pellet plant or further beneficiation Notes:  All processing steps should be monitored for process upsets; automation and regular maintenance are crucial for consistent plant performance. Cyclone and separator performance are routinely monitored (with up to 64 cyclones or more per module).  Lighter gangue minerals like Al2O3 (alumina), SiO2 (silica), and MgO are rejected during classification and spiral separation.  Plant configurations may vary depending on ore characteristics and final product shifts, but the above steps are standard for Indian and global beneficiation flowsheets.[2][3][1] If you need schematic diagrams or plant process flow charts, please specify. For each subprocess, operational safety, environmental controls, and product quality checks are mandatory. Let me know if you have specific sections to focus on or if you want this rewritten for a particular use case (training, documentation, presentation, etc.). ⁂