Energy-aware production scheduling of continuous slurry ball mills in tile industries with stirring time consideration

In this paper, a bi-objective mixed-integer model for energy-aware production scheduling of continuous slurry ball mills is proposed. Slurry ball mills are considered as the main consumer of electrical energy and impose high energy costs on tile factories. Hence, minimizing the energy costs associated with slurry production through implementation of peak-load minimization strategy and optimal assignment of orders to ball mills is the main goal which is considered in this study. On the other hand, the quality of slurry has a significant effect on the quality of produced tiles. An increase in time which slurry has left in rotating slip tanks, i.e. stirring time, helps improve its quality. Thus, the second goal which is pursued in this scheduling is compliance with the stirring time standards. The effectiveness of the proposed model is illustrated on a small-scale case study with a saving of above 15% in energy costs.