The decision about whether ArcelorMittal’s blast furnace A in Gijón will resume operation will come from a distance of 1,500 kilometers away from Asturias. Repairs to the furnace, which caught fire last Wednesday, require approval from the Luxembourg-based multinational’s leadership, and so does the plan to decarbonize the facility, a plan that involves investing 1,000 million euros. The outcome will determine if the plant remains a key pillar of Asturias’ economy by returning to pig iron production or if it will exit operation well before the end of its expected life, with the related reports flowing from Asturias. If a decision to repair is chosen, the best-case timeline suggests the furnace could be back in service no earlier than May.
The lifespan or remaining life of the furnace will hinge on the scope and cost of the repair work, and for the moment ArcelorMittal personnel are involved. The facility has not yet reached a critical point. The scene inside the plant, ominous as a crucible, reflects the tension. Cooling operations continue to ensure safe access to the furnace. By Sunday or Monday at the latest, the debris of pig iron and slag that settled at the bottom of the furnace will be removed in a process known as salamander. Once that is done, access to the interior will be possible to inspect the damage in detail.
Within two weeks the steel company hopes to have precise assessments of the furnace’s condition. At minimum, the repair will involve patching holes in the crucible and replacing portions of the refractory and cooling systems. The most favorable scenario would see the A furnace shut down until at least May. Yet company sources warn that if the entire refractory lining must be replaced, the downtime could extend by several more months, increasing costs and affecting the investment’s amortization. The project is also tied to an expected shift toward a direct hydrogen-fired iron ore plant and a hybrid electric arc furnace by 2025.
Because of the scale of work required, the final decision will rest with ArcelorMittal’s management in Luxembourg, weighing the scope of work against the reports from Asturias detailing damage and repair costs, as well as the status of other European plants. Technicians from Asturias are engaging with colleagues in South Africa, Mexico, and the United States, where similar blast furnace incidents have occurred, to exchange procedures and best practices for responding to the event.
The fire at blast furnace A in Gijón began last Wednesday afternoon during a routine maintenance operation. The furnace halted to replace a nozzle through which hot air enters, and an internal reaction occurred when pig iron in the crucible met water. The blast caused a breach in the crucible wall, through which pig iron escaped, and it also expelled material from the nozzle. The resulting explosion generated a large fire and a plume of smoke visible across much of Gijón and Carreño.
Officials noted that water within the crucible, which likely triggered the incident, has not yet been definitively identified. It is believed to have originated from the furnace’s own cooling circuits, with a probable leak in the crucible. In a blast furnace, temperatures can reach 1,600 to 1,800 degrees Celsius, high enough to damage the protective refractory lining that shields the steel shell. To counteract this, several cooling systems are employed. Water-carrying plates or slats lie above the refractory, and a ringed arrangement around the furnace distributes cooling water to maintain stability and prevent overheating.