Ceramics for Building Structures Made from Contaminated Soils: A Fuzzy Logic Intelligence Approach to Circular Mining

Soils contaminated by mining activities are a major environmental concern, and to avoid this type of environmental impact, carrying out high-cost processes is necessary. For this reason, a solution is proposed in this study in order to eliminate the soils contaminated by mining activities and, in turn, prevent the soil's contaminating elements from causing harm. All this is achieved by using contaminated soils as raw materials for the production of ceramics for bricks. For this purpose, the materials were initially characterized physically and chemically, and different ceramic test pieces were manufactured with different percentages of clay and contaminated soil, subsequently determining the physical properties and the leaching of toxic elements. In this way, it was possible to evaluate, via innovative data mining and fuzzy logic techniques, the influence of the contaminated soil's contribution on the properties of ceramics. Based on this, it was possible to affirm that the contaminated soil incorporation negatively affects the physical properties of ceramics as well as the leaching of polluting elements. The ceramic formed by contaminated soil and clay has a lower compressive strength, and it is associated with lower linear shrinkage and lower density, as well as higher porosity and cold-water absorption. However, the addition of different percentages of contaminated soil (up to 70%) to clay created a ceramic that complied with regulation restrictions. Therefore, it was possible to obtain a sustainable material that eliminates environmental problems at a lower cost and that fits within the new circular mining concept thanks to fuzzy logic techniques.