Particle separation is the broad metallurgical process of dividing a mixed stream of particles into two or more products based on differences in physical or chemical properties such as size, density, magnetism, surface chemistry, or optical characteristics. In bauxite processing, separation primarily relies on size and density differences to remove clay, quartz, and iron-rich impurities from usable ore. In gold mining, separation techniques include gravity separation exploiting the high density of gold, flotation exploiting surface hydrophobicity, and cyanidation exploiting chemical solubility, often used in combination depending on ore characteristics. In iron ore processing, separation is dominated by magnetic separation, which exploits the strong magnetic susceptibility of magnetite, alongside gravity and flotation methods for hematite ores. In diamond mining, separation relies on the unique physical properties of diamond, including high density for dense media separation and fluorescence under X-rays for X-ray luminescence sorting, since diamonds cannot be chemically dissolved or easily crushed for liberation. Particle separation efficiency is influenced by liberation degree, particle shape, surface coatings, and equipment design. Selecting the appropriate separation technique, or combination of techniques, is one of the most important decisions in flowsheet design, as it directly determines recovery, concentrate grade, operating costs, and the overall viability of a mining project.
