Online particle-size monitoring for hydrocyclone overflow: Where is the beacon?

Abstract

Monitoring the particle size-passing fraction (PSPF) at hydrocyclone overflow is critical for energy-efficient comminution and flotation. Knowledge of particle size distribution (PSD) beyond the single PSPF number can be yet more beneficial to plant operators. However, the large number of hydrocyclones typically employed in a processing plant and the necessity of monitoring each individual hydrocyclone unit have posed significant challenges to online PSPF and PSD monitoring. The questions are: What are the technologies available for online particle size assessment (PSA)? To what extent have these technologies been assisting the mining industry? Where is the beacon leading to a better solution? This paper reviews existing methods for PSPF and PSD online monitoring at hydrocyclones and classifies them into five categories — numerical, mechanical, attenuation, optical, and vibration. Evaluations are made in terms of online capability, system compactness, particle size range, performance robustness, measurement accuracy, maintenance requirements, and implementation costs, with comparison made and sensitivity analysis conducted. It reveals there is no single solution that excels in all evaluation criteria, and instead, different methods could mutually complement. Guidance is provided to assist the industry in selecting appropriate online PSA systems for hydrocyclone overflow based on different priorities. Data fusion and machine learning are recommended for further advancement in enhancing measurement accuracy and enabling self-calibration.