Life cycle assessment of refractory waste management in a Spanish steel works

• Published in: Waste management (Elmsford) Vol. 111; pp. 1 - 9
• Main Authors: Muñoz, Ivan, Soto, Aintzane, Maza, David, Bayón, Félix
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 15-06-2020
• Subjects: Ladle; LCA; MgO-C brick; Recycling; Refractories; Steel; Waste; Ladle; LCA; Recycling; MgO-C brick; Steel; Refractories; Waste
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2020.05.023

•Refractory waste management options assessed include reuse, recycling and landfilling.•Greenhouse-gas emission saving of 0.53 tonne CO2 per tonne waste produced.•Similar savings in energy, land and water use.•Refractory brick reuse shows higher CO2 savings than recycling by a factor four.
A life cycle assessment (LCA) is conducted on the current refractory waste management practices in a steel works in Spain producing around 6,000 tonnes of refractory waste in 2018. Management practices included direct reuse of spent magnesia-carbon (MgO-C) bricks, recycling of MgO-C bricks and high-alumina refractories by an external contractor and landfilling of monolithics and isostatic refractories, for which there were yet no established valorization routes. This current situation was compared to a hypothetical scenario where all refractories were disposed in landfill. The LCA included waste management activities (collection, transport, treatment) as well as production of substituted primary materials (dead-burned magnesia, calcined bauxite and new MgO-C bricks) produced in China and Germany. Results are discussed for four indicators: greenhouse-gas emissions, Non-renewable energy demand, land use and water use. Overall, per tonne of produced waste, the current management leads to a reduction or saving of 0.54 tonnes CO2-eq, 3 GJ primary energy from non-renewable sources, the occupation of 10 m2 of land during one year and the abstraction of 5 m3 freshwater. The results also show that reuse, in the particular case of spent MgO-C bricks, leads to higher benefits than recycling by At least a factor four. The robustness of these results is confirmed through the application of a Monte Carlo uncertainty analysis, as well as a sensitivity analysis focusing on a shift from coal to natural gas in the Chinese refractory industry.