PROPER: New sustainability metrics to improve refractories recycling performances regarding resource use, environmental impacts and economic benefits
Résumé
About 30 million tonnes of spent refractories are generated every year. Only 7% are recycled in the refractory sector when a larger amount is downcycled in lower value applications. The goal of PROPER is to assess the resource efficiency of closed loops refractories recycling through different lenses: environmentally using life cycle assessment (LCA), economically through a cost-benefits assessment including monetized environmental impacts and regarding resource use by assessing resource losses along the process.
To do that, three different refractory-based products are considered, distinguishing both primary and secondary production routes. Inventory data are drawn from extensive on-site collection regarding secondary production routes directly at the manufacturer site (Extracthive Ceramics Recycling), including in particular measurements of energy consumption, on-site dust emissions, and consistent mass balances. In parallel data for the primary routes were drawn from literature review and specific databases completed with expert judgement.
The LCA is completed with an assessment of resource losses using methods that assess resources dissipation and that were recently developed in the LCA world. Both the JRC-LCI and the average dissipation rate methods are here applied.
LCA results are also included in an economic assessment through monetary valuation. The goal is to look at the economic value of the secondary raw materials based on willingness-to-pay approaches and especially the discount associated to the use of secondary resources against primary ones. Apart from the monetary valuation of the environmental impacts, it includes the negative externalities associated to resource use linked to resource losses.
The combination of information regarding resources losses, environmental impacts and economic benefits allows the development of indicators to measure and improve resource efficiency of raw materials production processes.