Treatment of Soil Contaminated by Mining Activities to Prevent Contamination by Encapsulation in Ceramic Construction Materials

Juan María Terrones-Saeta; Jorge Suárez-Macías; Antonio Bernardo-Sánchez; Laura Álvarez de Prado; Marta Menéndez Fernández; Francisco Antonio Corpas-Iglesias

doi:10.3390/ma14226740

Treatment of Soil Contaminated by Mining Activities to Prevent Contamination by Encapsulation in Ceramic Construction Materials

Materials (Basel). 2021 Nov 9;14(22):6740. doi: 10.3390/ma14226740.

Authors

Juan María Terrones-Saeta¹, Jorge Suárez-Macías¹, Antonio Bernardo-Sánchez², Laura Álvarez de Prado², Marta Menéndez Fernández², Francisco Antonio Corpas-Iglesias¹

Affiliations

¹ Research Group TEP-222 "Materials and Mining Engineering", Higher Polytechnic School of Linares, Scientific and Technological Campus of Linares, University of Jaén, 23700 Linares, Spain.
² Department of Mining, Topography and Structures, University of León, 24071 León, Spain.

Abstract

Mining is an essential activity for obtaining materials necessary for the well-being and development of society. However, this activity produces important environmental impacts that must be controlled. More specifically, there are different soils near new or abandoned mining productions that have been contaminated with potentially toxic elements, and currently represent an important environmental problem. In this research, a contaminated soil from the mining district of Linares was studied for its use as a raw material for the conforming of ceramic materials, bricks, dedicated to construction. Firstly, the contaminated soil was chemically and physically characterized in order to evaluate its suitability. Subsequently, different families of samples were conformed with different percentages of clay and contaminated soil. Finally, the conformed ceramics were physically and mechanically characterized to examine the variation produced in the ceramic material by the incorporation of the contaminated soil. In addition, in this research, leachate tests were performed according to the TCLP method determining whether encapsulation of potentially toxic elements in the soil occurs. The results showed that all families of ceramic materials have acceptable physical properties, with a soil percentage of less than 80% being acceptable to obtain adequate mechanical properties and a maximum of 70% of contaminated soil to obtain acceptable leachate according to EPA regulations. Therefore, the maximum percentage of contaminated soil that can be incorporated into the ceramic material is 70% in order to comply with all standards. Consequently, this research not only avoids the contamination that contaminated soil can produce, but also valorizes this element as a raw material for new materials, avoiding the extraction of clay and reducing the environmental impact.

Keywords: ceramics; circular economy; construction materials; mining waste; mining-contaminated soils; potentially toxic elements; retention of potentially toxic elements; sustainability.