Grinding And Classification Process Control System Design And Application

The grinding-classification is an important procedure in concentrator. It is a complex, nonlinear, time-varying system. In this paper, the grinding-classification process control system was designed and applied in 4 million t per year concentrator of KISC in Yunnan Province.The relations between mill load and mill power, grinding density and grinding efficiency, and overflowing size and overflowing density were analyzed. Then control scheme of grinding-classification control system is proposed. Then, the process control scheme was proposed. A cascade control is used to make system well adapt to different ore. When the grindability of ore varies, the best feeding quantity will change. Base on this property, a parameter optimization was made to the best feeding quantity to avoid waste tamping or overloading, and make the mill play efficiency fully. Cascade control was applied to the input density, overflowing size and overflowing density of cyclones. The complex control scheme worked well as the system shown in real running condition.In addition, in this paper we provided configuration of hardware and software to the control system, from the 4 million t per year concentrator of KISC. It was reliable and advanced. It would be expanded easy, and it performed satisfactorily. The hardware of whole system consists of PLC control station, distributed I/O station, operation station / engineer station, and redundant network bus. Data communication is going on between control station and distributed I/O station through the data bus of PLC controlnet, between control station & operation station by industry Internet. We can monitor the control system on the operation station by Intouch 9.5 of Wonderware, effectively and vividly.