Circular economy in the hot-dip galvanising sectorpilot plant demonstration and environmental sustainability assessment

Abstract

The management of spent pickling acids is one of the environmental challenges of the hot-dip galvanising industry. The combination of non-dispersive membrane extraction (NDSX) and electrodeposition (EW) technologies is proposed for the recovery of zinc, iron and sodium hypochlorite from this residue. The scale-up of the NDSX process has been investigated, reaching a TRL 7. Likewise, a life cycle assessment (LCA) methodology has been developed and implemented for the environmental evaluation of the hot-dip galvanising process, identifying its critical stages, as well as the environmental benefits associated with the recovery of resources and the reuse of secondary materials. This doctoral thesis contributes to the application of the circular economy in the galvanising sector. The results provided in this work may be key to the preservation of natural resources, transforming waste into secondary materials, which allows satisfying the growing demand for raw materials, as well as reducing environmental impacts associated with their production.