Sidenor 2021 Sustainability Report. Non-financial information statement

63 Rolling sequencer Sidenor is aware that any inefficiency in its production process involves consumption deficiencies which drive us away from the purpose of optimisation. For this reason, throughout this year, we developed a rolling sequencer. After investing over 130 million euros in the technological update of this facility, we decided to implement a production optimiser which considers all activity restrictions, while minimising reheating furnace energy consumption (the main gas consumer in the MN mill). What is the rolling sequencer? It is an assistant for the rolling mill, which incorporates an algorithm that minimises temperature changes in the MN mill reheating furnace, while considering all activity restrictions. What does MN mill programming imply? Each order made by a customer becomes one or several manufacturing orders which gather the information necessary to the process. Based on each order’s rolling parameters, programming technicians perform a sequencing which guarantees the quality of steel and use of the facility. The sequencer issues sequencing suggestions through a heuristic developed ad hoc for the new mill. The suggestions minimise temperature changes in the furnace and consider all restrictions inherent to the activity. In addition, the sequencer integrates a sophisticated alert system which avoids any potential product quality problem. With this system, we improve the MN mill energy efficiency through a programming oriented towards environmental improvement and resource optimisation. Replacement of the Didier furnace door The replacement of the Didier furnace door in Azkoitia’s large mill will allow us to obtain a tightness that is much better than the current one, reducing gas consumption up to 5%, in addition to the corresponding reduction in greenhouse gas emissions. As part of the door replacement, the lintel has also been changed. Both doors and the current lintel work with a water cooling system which will be eliminated with the new modification, thus putting an end to a lot of problems related with cooling water. An example of a significant incident is the break of a blooming cylinder (22/02/2019) due to a water leakage in the door cooling, which completely cooled the central bloom part and, at rolling time, provoked the rupture of the upper cylinder in the blooming mill. EXAMPLES OF ENERGY EFFICIENCY