The Submerged Arc
The stainless steel mill dust, scales and other chromium- and nickel-containing production residues are delivered in containers and big bags by barge, rail or truck and fed to an intermediate storage. This makes it possible to transport the dust without risking any damage to the environment. The storage capacity is designed for the feed of two to three months’ production.
In a next step, the dust is blended with additives and briquetted. These briquettes are transported to an intermediate storage area and fed afterwards to the electric arc furnace together with coke and slag formers.
The electric arc furnace is tapped several times per day followed by a gravity separation process to separate the metal phase from the slag. The recovered metal is returned to the customers as large slabs or it is sold on the free market. The slag is used in road constructions or as a soil substitute at deposit sites.
The off-gases generated by the process are cleaned in a multi-stage off-gas cleaning system.
The submerged arc furnace process consists of the following stages: