The Use of Submerged Arc Furnace (SAF) as a Robust Technology for Upcycling Waste into Standard Mineral Products for Construction Industry

The greatest challenge in the 21st century is to transform a linear economy into a circular and environmentally friendly economy. Landfilling mineral wastes, mainly those caused by mining and metallurgical industry, are one of the most considerable problems to confront. The submerged arc furnace, a technology extensively used for metal extraction, is a technology capable of treating and cleaning countless mineral wastes, thereby permitting elaborate valuable mineral precursors for the construction industry. Whether conditioned slags can through high-temperature treatments fulfil local and national regulations in terms of content and leachability of pollutants, several near zero-waste upcycling strategies can be carried out for the building sector. This article is a review of the present and past work made by IME Process Metallurgy and Metal Recycling, RWTH Aachen University in collaboration with industry and others universities showing how Submerged Arc Furnaces can successfully treat a wide range of residues from tailing ores such as bauxites residues, ashes from Waste to Energy plants to hazardous metallurgical slags, i.e. copper and lead slags. Upcycling solutions include their use as aggregates for road paving and concrete, additives for cement, and finally bricks, tiles, and acoustic and thermal isolation materials via inorganic polymers or glass-ceramics.