Environmental Impact Assessment of Substituting Virgin Garnet with Recycled Alumina Abrasives in Abrasive Waterjet Cutting

Grinding, a common finishing process, relies on grinding wheels that, once worn out, are often discarded in landfills, contributing to environmental concerns due to their non-biodegradable composition. A sustainable alternative end-of-life solution involves repurposing the abrasive component, like alumina, from grinding wheels waste as feedstock for abrasive waterjet cutting (AWJC), traditionally using virgin garnet, whose environmental impact is considerable due to its reliance on raw material extraction. This study assesses the environmental impact of using recycled alumina abrasives derived from grinding wheel waste as a substitute for virgin garnet in AWJC, analyzing two treatment methods, mechanical and chemical separations, using existing literature data. Results show that replacing virgin garnet in the AWJC with recycled alumina achieves a reduction in the AWJC overall impact by 35-38%, as per the ReCiPe 2016 method, with the highest reduction observed in the ‘mineral resource scarcity’ category. The virgin garnet’s impact predominantly stemmed from mining and transport, accounting for around 61% and 39%, respectively, assuming a cutting process located in Belgium. In all scenarios, higher abrasives’ reusability consistently enhanced environmental performance, with the effect being particularly pronounced in garnet-utilized cutting process due to the diminished need for garnet mining. Despite recycled alumina’s higher energy demand for size reduction, the environmental gains from substitution were marginally influenced, underscoring virgin garnet’s significant role in the AWJC impact. This study emphasizes opportunities for sustainable manufacturing by fostering industrial symbiosis, thereby enhancing resource conservation and environmental sustainability.