From waste to valuable resources: exploitation of mineral waste in civil and environmental application.

Abstract

Mineral wastes coming from demolition activities, including rock and soil from excavations, and extractive industry, represent the first and the second source of waste production at EU level (35.9% and 26.6% respectively). Although some of these waste products can cause environmental and economic problems if not adequately managed and disposed, they represent an alternative resource for civil, building, infrastructure and environmental applications. This study introduces the state of the art of the research and applications of products arising from mineral waste, with a focus on new potential application of fine fractions for artificial substrate production. The agronomic characteristics of the produced mixes were tested to evaluate their use and the environmental criticalities for land rehabilitation. The results showed that, when mixed with organic materials, the overall quality and fertility of the mineral waste fine fraction was improved, and that this mixture was not phytotoxic. This indicates that when properly managed and treated the mineral waste fine fraction could be effectively employed for land rehabilitation. In general, both coarse and fine mineral waste fractions are valuable alternative construction materials for buildings infrastructures and environmental applications. Sustainable and circular management of mineral waste contributes to guarantee raw materials supply, contemporary reducing environmental (including CO2 production) impacts associated to waste management and landfilling. The potential decrement of environmental impacts and CO2 production will contribute to enhance the NET-zero greenhouse gas emissions EU strategy. Statement of Novelty The present research outlines the possible reuses of different mineral wastes coming from demolition activities and rocks and soils from excavation works as a replacement for natural aggregates, in line with the circular economy paradigm. These materials represent the first source of wastes (in mass) in Europe and innovative processes for their efficient reutilization are needed. This research addressed the main problems connected with their management, focusing on some experimental processes, such as the production of artificial substrates, as a sustainable alternative to contrast the land consumption. However, the updating of the current legislation and the inclusion of these new products for public works (Green Procurement) is regarded fundamental to the effective application of novel technologies.