Recent Developments in Flotation Column Instrumentation and Control: An Update

Abstract

Abstract -For over two decades, LOOP (French acronym for Process Observation and Optimization Laboratory) researchers have been working at developing and/or improving specific sensors for flotation columns and their use for automatic control of this process. Several papers have already been published for the mineral processing industrial and scientific community in peer-reviewed journals and conference proceedings, but very few have been presented in European conferences. This paper summarizes the latest milestones completed by the group. On the instrumentation side, developments encompass a more accurate method for measuring electrical conductivity for flotation column sensors, a device for estimating the bias rate, and a better procedure for evaluating bubble size from images taken by bubble viewers. In terms of process control advances, the discussion will focus on results for bubble size control in a two-phase system, and the application of a 2x2 multivariable predictive control to a pilot flotation column running in parallel to industrial columns in a Québec concentrator. Finally, the latest work on twophase bubble size distribution modeling and control will be summarized