A mineral processing circuit is the specific configuration and sequence of unit operations — comprising equipment types, interconnections, material flow paths, and control systems — through which ore is processed to achieve the desired mineral separation and product quality outcomes. The design of a processing circuit is determined by the mineralogy, liberation characteristics, and grade of the feed ore, as well as the target product specifications and economic parameters. Circuits may be open (no recycle streams) or closed (with recycle of oversize, underflow, or middlings back to an earlier stage), and can incorporate various combinations of comminution, classification, and separation stages. In a typical iron ore magnetite processing circuit, ore passes through primary crushing, then a SAG and ball mill grinding circuit operating in closed loop with hydrocyclones, followed by multi-stage low- and high-intensity magnetic separation to produce a fine magnetite concentrate, which is then filtered, dried, and pelletized or pumped as slurry. A gold CIL (carbon-in-leach) processing circuit integrates gravity concentration, primary and secondary grinding, thickening, cyanide leaching, carbon adsorption, elution, electrowinning, and smelting. In diamond processing, circuits combine scrubbing, screening, dense media separation, X-ray recovery, and grease belt or final hand-sorting stages. Processing circuit performance is monitored through metallurgical accounting, sampling campaigns, and mass balance reconciliation, and circuits are progressively optimized through adjustments to throughput rates, reagent dosages, grind sizes, and operational parameters.
