Innovative use of copper mine tailing as an additive in cement mortar

This research assesses the feasibility of recycling copper mine tailings (CMT) by analyzing the durability and mechanical characteristics of cement mortar using these tailings as filler additives. CMT are mineral wastes generated during the process of mining. In this work, specimens of cement mortar were added with up to 30 wt.% of a CMT. Bulk density, dynamic modulus of elasticity, apparent density, ultrasonic pulse velocity, flexural and compressive strengths tests were used. Total amount of voids, sorptivity, water absorption and chemical resistance tests were also performed to evaluate the durability. Incorporating CMT into cement mortar improved the mortar performance. When 10 wt.% CMT was added, overall voids in the mortar were reduced by 20 % and mechanical performance was improved by 16 % after 28 days. The flexural strength of the mortar was also found to increase with the addition of CMT, with the 20% wt.% CMT mortar mix reaching a flexural strength of 5.89 MPa, which represents a 16 % increase compared to the control 0% CMT strength. The results indicated that there was not a perfect correlation between these results and the mechanical strength results for the 15 and 20 wt.% CMT mixes. In addition, the CMT acts as a protective barrier against harmful chemicals. The results of this research indicate that reusing CMT by incorporating into cement mortar is a feasible method for their recycling. Mortar made with as much as 15 wt.% CMT presented the same strength and durability as mortar with traditional sand and cement.