Modelling some aspects of the maintenance management of the working refractory lining of small electric arc furnaces in the steel industry

In this paper, an optimal replacement cycle model, involving the costs of the replacement, hot repairs and cold repair was developed to suit the particular application of optimizing two aspects of the maintenance management of the working refractory lining of small electric arc furnaces (EAF) in steel making. Those aspects were the ranking of the various refractory material options for purchasing purposes and that of the operational control of the timing of the complete lining replacement in the absence or presence of a cold repair. Dealing with cold repair required special attention. The treatment took into consideration the particular aspects of refractory lining construction and maintenance and replacement theory and models as they relate to small EAF steel making. As such, the general approach of modelling the optimal replacement cycle of deteriorating single assets and the repair limit criterion were forged together to develop the targeted ‘Working Lining Optimal Replacement Cycle Model (WLORCM)’. The model proved to be capable of achieving the set objectives and, in the case establishment LISCO, of demonstrating the possibility of achieving considerable savings. Likewise savings can be achieved in similar establishments.