Consequences of Switching From Lime to Dololime Fines Injection in Electric Arc Furnace

Abstract

This study presents a successful solution implemented at a steelmaking plant of the company United Steel in Kuwait. The primary challenge addressed in this study involves the generation of excessive dololime fines (particles less than 10 mm) and insufficient lime fines (particles between 5 and 15 mm) at the lime and dololime plant. This size disparity presents operational challenges within the steelmaking process. An innovative strategy is implemented to overcome this disparity and optimize material utilization. The solution involves replacing lime fines injection with dololime fines injection in the electric arc furnace. The original practice employs a combination of lime fines injection with the use of lime and dololime lumps. The proposed solution replaces the lime fines injection with available dololime fines. To maintain the required mass balance, the quantity of lime lumps is increased, while dololime lump usage is reduced. The implemented strategy results in several key improvements. Lime and dololime consumption demonstrably decrease, indicating improved material efficiency. The economic benefits are significant. By eliminating the need for external briquetting of dololime fines and reducing purchased lime fines quantities, the solution generates annual cost savings of approximately USD 350,000.