C3. Environmental assessment (LCA)
To evaluate the environmental feasibility of the reclaimed SFS, a life cycle assessment (LCA) has been conducted in accordance with the standard ISO 14040:2006 “Environmental management - Life cycle assessment – Principles and framework” and ISO 14044: 2006 “Environmental management - Life cycle assessment - Requirements and guidelines”. The environmental impacts of the LIFE ECO-SANDFILL reclaiming process have been assessed and compared with those of the thermal reclamation and the production of virgin sand.
The goal of the LCA has been to evaluate and to compare the environmental impacts of the reclaimed SFS through two different reclamation technologies:
- Novel LIFE ECO SANDFILL mechanical process running in the prototype installed in ESTANDA foundry.
- Thermal reclamation process previously existing and working in ESTANDA.
The environmental performance outputs of both reclaimed foundry sand types are also compared with impacts associated with virgin natural sand. Considering that applications in construction sector are foreseen for the reclaimed sand, the impact categories assessed have been those defined in the product category rules of the EPD International system for highways, streets and roads (except elevated highways).
Impacts of 1 t SFS reclaimed by the mechanical LIFE ECO-SANDFILL technology are lower than the impacts originated in the thermal reclamation process of 1 t of SFS, for all the categories assessed except for the Abiotic Depletion Potential (similar values in the same range).
When comparing mechanically reclaimed SFS in the project prototype with two different types of virgin sand, sand at mine and silica sand flour (average industry data, source: ecoinvent 3 LCI database), the environmental profile of the reclaimed SFS is better than those of virgin sand. That means that the use of this reclaimed SFS will bring a positive net environmental effect, regardless of the sector in which they are used or the substitution ratio of the virgin sand by the reclaimed SFS.
