LCA as a decision support tool for evaluation of best available techniques (BATs) for cleaner production of iron casting

Abstract

Over the last decades, stringent regulations forced the manufacturing industry to take concrete steps towards greener production. Despite reduction in total emissions through implementation of best available techniques (BATs), industrial waste generators still need guidance to minimize environmental impacts of manufacturing processes. The metal industry remains one of the most important waste generating sector and therefore, this study focused on one specific process, iron casting and used a life-cycle approach (LCA) to evaluate the performance and cross-media effects of the BATs applicable for this industry. A streamlined LCA (raw material transformation to production of ductile iron casting piece) was performed to evaluate the impact of eleven BATs. The life cycle inventory was created using industrial average data for European iron casting industry from the literature. The avoided burdens originating from reduced raw material consumption and reuse of process residues were considered. Since economic factors largely influence methods to be implemented, the most preferable strategies towards cleaner production in iron foundries was determined using a combination of achieved benefits, environmental impacts and cost of implementation. Among the techniques evaluated, on-site recovery and external reuse of waste sand were capable of decreasing overall environmental impact of casting by 60–90%. Additionally, these techniques created revenues and savings for the manufacturers, which lead to the possibility of a step-wise implementation scheme to reduce financial burden of cleaner production programs in foundries. Overall environmental and economic evaluation suggested that planning towards cleaner production should adopt a holistic approach rather than being restricted to waste hierarchy principle.