Use of Al-Killed Ladle Furnace Slag in Si-Killed Steel Process to Reduce Lime Consumption, Improve Slag Fluidity

Abstract

Slag is a by-product formed in most metallurgical process. During the steelmaking process a large amount of slag is produced, which becomes a source of waste, which in many instances is land filled. Such areas filled with waste materials have become a significant source of pollution. Slag recycling is then becoming important in recent years. Recycling can be an efficient option to reduce such waste. Fluorspar (Calcium Fluoride) is generally used to help fluidize the slag; however, Fluorspar has a corrosive effect on the ladle refractory and is environmentally harmful. Alternatively, Calcium Aluminate synthetic slag is very effective in making the slag more fluid, but it is costly. The slag generated in Al-killed treatment at ladle can provide a material with advantages over Calcium aluminate synthetic slags and Fluorspar, by being low-cost, noncorrosive, and less environmentally harmful. Plant trials conducted at Hadeed indicate that Al-killed ladle slags coming from its Flat Product Ladle Furnace process could be used in place of Calcium Fluoride/ Bauxite/Calcium Aluminate fluxes for the production of Si- killed steel grades, thus reducing Lime consumption, reducing waste and improving desulphurization levels.