Particle size distribution (PSD) describes the relative proportion of particles falling within different size ranges in a given sample, typically presented as a cumulative percentage passing curve. PSD is one of the most important characteristics of any processed ore stream because it governs downstream processing behavior. In bauxite processing, PSD affects settling rates in thickeners and digestion efficiency, with a well-controlled PSD improving alumina extraction and reducing scaling issues. In gold processing, PSD directly impacts liberation of gold-bearing minerals, and grinding circuits are specifically designed to achieve a target PSD, often a P80 value, that balances recovery against energy costs. In iron ore processing, PSD determines suitability for different steelmaking feed types, as sinter plants and blast furnaces require different size fractions and excessive fines can cause operational problems. In diamond processing, PSD determines which recovery technology, from dense media separation to X-ray sorting, is applied to each size fraction, and understanding PSD helps prevent over-crushing that could damage valuable stones. PSD data is typically presented graphically and summarized using parameters such as P80, P50, or the coefficient of uniformity. Engineers use PSD information to design and optimize crushing, grinding, and classification circuits, ensuring that each stage of the plant operates within its intended performance envelope.
