Automatic flotation control- a review of 20 years of effort

Abstract

Some twenty years ago, the first on-line devices for measuring the metal content of flotation slurries became available. As a result, the first studies in the automatic or computer control of industrial flotation circuits commenced. The development of robust and lasting automatic control systems for flotation circuits has proved difficult. Reasons for this include the inherent complexity and unpredictability of the response of most flotation circuits to upset consitions, unclear expectations of what a control system can achieve, unrealistic objectives for control systems and excessive complexity of the actual control strategies. However, the interest in developing control systems has persisted because the benefits to be gained in terms of improved metallurgical performance are substantial. A pattern of development has emerged for flotation control systems. Most of the early systems were concerned with some form of stabilizing control, although a few systems were aimed directly at optimization. It is now generally accepted that stabilizing control must precede optimization, and the focus has shifted to a range of increasingly sophisticated approaches to achieve stabilization by the use of various model based control strategies. A recent development is the application of expert systems as the crucial role and knowledge of operators are being appreciated.