Mineral processing - WikipediaIn the field of extractive metallurgy, mineral processing, also known as ore dressing, is the process of separating .. Gravity separation is one of the oldest technique in mineral processing but has seen a decline in its use .. The first pair of electromagnets was weakly magnetised and served to draw off any iron ore present.gravity separation of iron ores,Iron Ore Beneficiation with Packed Column JigKeywords: iron ore, gravity separation, fine particles, packed column jig. . During the last few decades, low-grade finely disseminated iron ore deposits have.