Implementing Real-time Optimization on a secondary Cone Crusher for Iron Ore Production, part 1

Other conference contribution, 2013

Cone crushers are often used as an intermediate comminution step in the mining industry. Real-time feedback data on the product streams can be obtained by applying mass-flow sensors to the process. Systems used for controlling the Closed Side Setting (CSS) on cone crushers are widely used to compensate for wear of the manganese crushing liners and to protect the machines from overloads. With a frequency converter also the eccentric speed in a cone crusher can be adjusted in real-time in addition to the CSS. The eccentric speed affects the dynamic interaction between the rock material and the crusher liners. The adjustment of these two online parameters in real time can result in an increased potential for production yield; however, a nontrivial optimization problem with a large solution space also arises. As the feed material also varies, and the wear is highly evident, the optimal setting for the parameters varies in time. In this paper we report on the preparation of a secondary cone crusher for real-time optimization. The cone crusher, a Sandvik CH680, has got a frequency converter installed and the temperature in the crusher is measured in order to ensure that the crusher as a mechanical machine is working under good operating conditions. The conveyor belts around the crusher have all been equipped with mass-flow meters. Thus the different product yields from the crushing plant can be monitored continuously. The results of the electrical and instrumental installations are that both the CSS and now also the eccentric speed can be operated and monitored in real time without interrupting the process at one of LKAB Malmbergets secondary cone crushers. The first guiding tests indicate a more beneficial operating point, where a higher power consumption can be achieved in the crusher without increasing the pressure as much. The results of the capacities, both the crusher and the crushing stage, indicate the same direction. There are operating points which are more beneficial than others, and it is not the nominal one that is the best. The range of the change in capacity of the circuit is -6.1% to +2.3% from the nominal point.