Iron Ore Types & Beneficiation Approaches
Iron ore deposits include magnetite ores (strongly magnetic, typically 20-35% Fe), high-grade hematite / goethite direct-shipping ores (DSO, typically >55% Fe), lower-grade banded iron formation (BIF) hematite ores requiring beneficiation, and iron ore fines suitable for pelletizing. The beneficiation approach depends strongly on the ore type and mineralogy.
WSHT designs custom iron ore beneficiation flowsheets for each specific deposit type.
Crushing & Screening for Iron Ore
For both magnetite and hematite deposits, crushing and screening are essential first steps. Primary jaw crushing, secondary cone crushing and (for higher-grade ores) tertiary crushing produce sized lump ore and fine ore products. Multi-deck vibrating screens classify products into size fractions — with the lump fraction typically sold directly and the fine fraction reporting to beneficiation and/or pelletizing.
WSHT designs high-capacity iron ore crushing and screening circuits with reliable, low-wear equipment suited to abrasive iron ore.
Magnetic Separation for Magnetite Ores
Magnetite iron ore beneficiation relies primarily on magnetic separation. Low-intensity magnetic separators (LIMS / drum magnetic separators) recover magnetite at coarse and intermediate grind sizes. High-intensity magnetic separators (WHIMS) may be used to recover hematite and other weakly magnetic iron minerals.
Magnetic separation circuits typically include 1-3 stages of magnetic separation with intermediate regrinding to achieve the required concentrate grade.
Gravity Concentration & Flotation for Iron Ores
Gravity concentration (spiral concentrators, jigs, tables) is used to upgrade certain hematite / goethite iron ore deposits, particularly where liberation sizes are coarse and gangue minerals have significant density differences from iron oxides.
Reverse flotation (floating silica gangue while depressing iron oxides using starch or other depressants, or cationic flotation of silica) is commonly used to upgrade iron ore concentrate grade and reduce silica content — producing high-grade pellet feed.
Concentrate Dewatering & Pelletizing
Iron ore concentrate is dewatered using thickeners, filters and drying equipment. For pellet-feed-grade concentrate, iron ore pellets are produced in balling drums or discs, then indurated in rotary kilns or straight-grate furnaces to produce high-quality blast furnace and direct reduction (DR-grade) pellets.
WSHT designs complete crushing, beneficiation, dewatering and pelletizing plant flowsheets for integrated iron ore projects.