At present, the steel plant adopts the manual method to carry out the ladle scheduling, the optimization results of the ladles selection are not good enough because of the uncertainty of ladle temperature, ladle life and ladle materials. Ladle scheduling is to select and distribute the ladles based on the heat plan, providing that the process time of heats and the process requirement of the dephosphorization for heats are given. The selection of dephosphorization ladle takes the performance index of maximum temperature, highest life, and the remaining online ladle life. Take the ladle temperature in the specified range, the ladle life within the specified range and the ladle maintenance end time as early as the furnace processing time as the constraints to determine the dephosphorization. This paper adopts consistency classification method to obtain the dephosphorization ladle rule, and use the rule-based reasoning to get dephosphorization ladle. The performance is tested by simulation experiments. The experimental results show that, compared with the manual scheduling, the algorithm enables the production work well and improve the production efficiency, and improve the economic efficiency of enterprises.

According to the conditions of the low level of automation and low labour productivity，an automatic control system for flotation
process was designed and developed innovatively based on the ControlLogix series software and hardware platform of Ｒockwell Company．
The structure and function of the control system are introduced carefully． The control strategies of the pulp level，the air flowrate
and the flotation reagent feeding are described in detail． The control software and human － machine interface are designed and developed．
The actual industrial application results show that the control system operates steadily，safely and reliably，the worker labor intensities
are decreased obviously，and the work condition is improved，the competitiveness of the enterprise is enhanced．