Ore dressing, also called mineral processing or beneficiation, refers to the physical and chemical treatment of mined ore to separate valuable minerals from worthless gangue material, producing a concentrate suitable for further refining or direct sale. Typical stages include crushing and grinding to liberate mineral grains, followed by separation techniques such as gravity concentration, magnetic separation, froth flotation, or chemical leaching, depending on the mineralogy involved. Bauxite ore dressing usually involves crushing and washing to remove clay and silica before the ore enters the Bayer chemical refining process, which extracts alumina using caustic soda. Gold ore dressing commonly uses gravity concentration, flotation, and cyanide leaching or, for refractory ores, pressure oxidation and roasting prior to leaching. Iron ore dressing relies heavily on crushing, screening, and magnetic or gravity separation to upgrade Fe content and remove silica and alumina impurities. Diamond ore dressing is distinctive in that it preserves rather than destroys the valuable mineral, using dense media separation, X-ray transparency sorting, and laser or grease-table techniques to recover intact diamond crystals without damaging them.
