Effect of mining residues treated with an electrodialytic technology on cement-based mortars

Abstract

Mining residues have been accumulated for centuries due to excavation and mining processes, causing environmental degradation worldwide. Their application in cementitious products is a feasible alternative to waste disposal. Electrodialytic technologies can promote a safer reuse of mining residues in the construction sector, coupling economic advantages due to the possible removal of toxic elements and the recovery of critical raw materials. The application of treated mining residues in construction products, namely their effects on physico-mechanical properties, in comparison to raw residues and cement uses needs to be addressed. This work presents a study of cement-based mortars with the incorporation of mining residues treated with an electrodialytic process in comparison to raw mining residues. The replacement percentages studied were 0, 10, 25 and 50 % of the binder in volume. Tests were conducted to evaluate fresh and hardened properties of mortars considering physical, microstructural and mechanical performances. Results show the viability of applying mining residues after the electrodialytic treatment as mortars materials in rendering, plastering, joint repointing, bedding masonry or screed requirements, with improved thermal conductivity and eco-efficiency.