Minerals processing plants typically use grinding mills in closed circuit with hydrocyclones to produce a product with a specific particle size distribution for optimum downstream process recovery. Exist-ing instrumentation that provides particle size measurement is considered standard in most modern concentrator plants. However, instrumentation availability is often very low, mainly owing to high maintenance requirements of the analyzer and associated sampling system.

A novel and robust technology has been developed that provides a highly reliable and low maintenance system for online measurement of the particle size in the overfl ow of individual cyclones. The system is based around a wetted sensor design with no moving parts and provides a real-time trend of the desired target grind size parameter, such as a percentage retained on screen (e.g., % +100 mesh). The system does not require sampling and associated sample transfer piping that is prone to plugging, thus avoiding high maintenance requirements.