Comparative life cycle assessment of ornamental stone processing waste recycling, sand, clay and limestone filler

Owing to the cost of destination and transportation of ornamental stone processing waste, many studies focused on the reuse and recycling of this product. However, there is a scarcity of articles addressing the environmental viability of the recycling of ornamental stone. In this context, this study comprehends a comparative life cycle assessment of ornamental stone processing waste and conventional materials: sand, clay and limestone filler. The modelling software used was SimaPro 8.3.0.0 with Ecoinvent 3.2 database, employing the ReCiPe H/H methodology for impact assessment. The results show that the recycling of ornamental stone processing waste is environmentally preferable, and the artificial drying alternatives, such as flash dryer and rotary dryer, have lower environmental impact than extracting and processing clay through atomisation methods and limestone filler production. The sensitivity analysis indicated that it is possible to transport the ornamental stone processing waste 37 km after processing, so it reaches the same environmental impact as sand extracted by dredging. On the other hand, an increase of 25% in the energy consumption incremented only 7% of the environmental impact owing to the Brazilian energy mix.