Sidenor Corporate Report 2019

42 Corporate report 2019 | Environment Heat recovery All our billet heating furnaces feature heat recovery systems that use the gases generated to preheat combustion air and, therefore, reduce natural gas consumption. Waste We want to get the most out of the use of our resources. One of the most outstanding examples is our will to reuse and valorise the auxiliary materials used in the iron and steel industry. This is the case of the iron and steel aggregate obtained from the valorisation of black slag waste. For this product, we have various EC-marking certificates which include its use as granular layers, bituminous mixtures and concretes. As an example of application for bituminous mixtures, two of the internal roads were made in our Basauri centre. Likewise, Sidenor is a partner in the BIRBALAS project, whose final objective will be to develop new railway ballast and sub- ballast products from electric arc furnace slags and, thus, to open a new path for the management of this waste as well as to ensure, at the same time, compliance with specifications that guarantee its functionality as well as environmental safety and adequacy. Along the same lines, we have been able to valorise a large part of our waste by means of innovative practices. White slag is used in cement production processes; steel mill dust is used in the zinc recovery industry; and mill scale is used in sintering plants for blast furnace iron and steel processes. DECANTER Dirty water (scale and oil) Oils are removed by means of flotation Valorisation of oils externally The sludge is managed externally as waste The sludge “dries” in a filter press Solids, of a higher weight, decant Purified water ready for reuse