Since large pumps became available in the 1950’s with enough capacity to create rotary motion required for cyclone classification, the cyclone has held a strong place in the minerals processing industry (Lynch, 2015). Cyclones are simple to use and have large turndown ratios making them the preferred choice for large closed grinding circuits, and will likely remain so for the near future. Despite their simplicity, cyclones are imperfect classifiers and have inefficiencies associated with fine and coarse material bypassing to the undesired stream. Furthermore, even though cyclones are normally arranged in a cluster or pack, and fed by a common distributor, individual performance can vary significantly. Cyclone performance can severely impact overall plant performance through grinding efficiency (unwanted fines in ball mill feed), throughput (shut down due to blockages) and mineral recovery (through unwanted coarse material in the feed for the downstream separation process).

This paper presents a novel and robust technology that has been developed with an industry partner to address the challenge of unwanted coarse material in cyclone overflow streams. The CYCLONEtrac particle size tracking (PST) system will be described in detail along with the calibration approach for which a rapid method for analyzing cyclone overflow samples was developed to minimize the errors involved. The system has sensors installed on individual cyclones, providing a particle size measurement, thus performance monitoring of individual cyclones. This compares to the traditional approach of measuring a sample stream of the consolidated overflow from a cyclone cluster. Plant data will be presented showing the value of individual measurement.