Contemporary advanced control techniques for flotation plants with mechanical flotation cells – A review

• Review of researches in control of flotation plants with mechanical flotation cells.
• Hierarchy of flotation control levels is often described through 3 or 4 levels.
• MPC is the result of advanced control method in a multi-variable environment.
• Expert knowledge based methods still to find their place in existing schemes.

Successful control of flotation plants in modern conditions represents a challenging and complex task that has yet to be accomplished. There have been multiple attempts, however, to find an appropriate control technique that would completely cover the dynamic, complex and poorly-defined flotation system. This paper presents a literature review of current theoretical and applied researches in the field of control of flotation plants with mechanical flotation cells. Significant aspects of the stratification of control levels are described in the paper, with emphasis on advanced techniques that include predictive and intelligent control methods.Traditional PID controllers are found not suitable for the comprehensive control of dynamic flotation systems, except, in part, for the lower hierarchy levels. In the area of advanced control, model predictive methods can improve flotation process performances, but as a rule, in a short period of time. Intelligent methods are playing a significant role in flotation process control, increasing its flexibility, although none of the available variations completely satisfy all the process control aspects.Bearing in mind the results achieved so far, further improvements are expected in the areas of overall control strategy, individual control components and repositioning of advanced control methods.