Reduction in blast furnace operational costs through optimisation of auxiliary systems

The process of steel making is very energy intensive. Across the world, steel plants are investigating ways to reduce energy cost. Although there are different approaches to energy management in the global steel sector, this study focusses on the South African steel industry, which is ranked the 25^th largest producer within the global steel industry. The South African steel industry has experienced a number of challenges over the past few years, including, but not limited to, higher cost of energy. In order to continue producing competitively, energy cost saving measures are needed. The blast furnace is complex, but an important component of steel making. However, it has the highest energy intensity of all the integrated steel making processes. Previous blast furnace studies investigated the possibility of doing a load shift on a blast furnace cold blast system. It was found that due to the risks involved it was not possible. This study will focus on the optimisation of auxiliary systems of the blast furnace. In a case study, successful energy saving strategies were implemented on the cooling system and Pulverised coal injection plant. The total energy cost savings achieved was in excess of R750 000.