Converter life enhancement through optimisation of operating practices

Abstract

Converter lining life is an important technical and economic concern of the steelmaking process. An increase in lining life decreases refractory consumption and reduces steelmaking costs. Increased availability of furnaces increases production rates and steel yield. Extended lining life was achieved by utilising the slag as a consumable refractory by splashing it over the lining. Slag splashing is a simple and effective technique followed worldwide to increase the converter life. This paper highlights the online study on various operating parameters and slag characteristics for consistent slag splashing in a 130 t converter. Parameters such as lance height, blow pattern, gas flowrate, bottom purging flowrates, tapping temperature, combination of gunniting with splashing, slag height and slag chemistry, were investigated. An optimised slag has been developed which served effectively to balance the lining erosion during blowing and maintain a uniform thickness throughout the campaign. Some innovative practices and design changes are also discussed. The developed slag regime and optimised parameters have helped in increasing the converter life to an international benchmark. JSW Steel has achieved the converter lining life of 13 771 heats, which is the highest ever recorded in India.