Developing an Evaluation Model for Cost Saving Initiatives on Sinter Plants

The South African steel manufacturing industry is under immense financial pressure. This is due to continuously rising energy and operating costs. Meanwhile, local steel producers are faced with demands to remain competitive in a market flooded by cheaper imported steel. The investigation and practical implementation of improved efficiencies, load shifting and peak clip projects are thus required to alleviate operating costs for local manufacturers. This paper thus details a developed evaluation process to identify and investigate energy cost saving opportunities on a sinter plant at a local integrated steelworks. Required for raw materials preparation, the sintering process is an intense consumer of electricity. A comprehensive literature review identified several existing energy saving opportunities applicable to sintering processes. A cost saving initiatives evaluation model was thus developed to identify and rate the feasibility of the opportunities for the local steel industry. The evaluation model, enhanced by a developed simulation, revealed that the alignment of production scheduling with Eskom’s time-of-use (TOU) periods was the most feasible opportunity. Pilot studies showed that an electrical consumption load shift of 9-14 MW was achievable. A 9 MW load shift equates to an annual saving of R10 million. The pilot studies thus confirmed that the optimisation of production schedules will reduce electricity costs on sinter plants.