Study of feasibility of using copper mining tailings in mortar production

Abstract This study assesses the technical feasibility of replacing portions of the cement in mortar mixes with copper mine tailings, with a particular focus on mechanical strength. Compression, flexural, workability (flow test), and splitting tensile strength tests were conducted with different replacement percentages of cement by copper tailings (10, 20, and 30%). The experimental setup included three study cases: (i) fine aggregates, (ii) coarse aggregates, and (iii) fine aggregates with double the cement/tailings dosage ratio. The results revealed a decrease in mechanical strength as the percentage of mining tailings increased for compressive and tensile strength. However, the compressive and flexural strength increased when the cement-to-water ratio was increased in which case good mechanical results were obtained. In particular, in case (iii), the flexural strength increased by almost 40% when a mixture with 30% of copper tailings was used. Thus, the results obtained here suggest that it is feasible to use copper tailings in the manufacture of mortars, achieving acceptable mechanical strength and promoting a circular economy in copper extraction.