An Investigation of the Characteristics and Microstructure of Gold Tailing Powder Utilized as a Cement Substitute

Abstract

This research studied the feasibility of using tailings waste from gold mining as a partial replacement for cement in standard concrete mixes. Its objective was to determine whether the addition of tailings waste could meet or exceed the specifications of standard concrete. Another goal of this study was to provide solutions for the utilization of waste that will benefit the environment and the economy. The tailings substitutions used in this study were 5%, 10%, 15%, 20%, and 25% of the mix. Their content is similar to that of cement, including Fe2O3 = 8.52%, Al2O3 = 15.50%, and SiO2 = 49.01%. The slump value of standard concrete was 80 mm and that of concrete with 25% tailings substitution was 55 mm. Ordinary concrete has a compressive strength between 20 MPa and 40 MPa. The strength of concrete mixes reduced as the proportion of tailings waste rose, according to tests conducted 28 days after the concrete had aged. The mix with 10% substitution had the best performance with a compressive strength of 53.32 MPa and a tensile strength of 3.61 MPa. Although the tailings contain similar compounds to cement, it was shown that when the amount of tailings that substituted cement in concrete mixes was increased, decreasing values were observed for workability, compressive strength, and tensile strength. Nevertheless, these decreases still meet the standard specifications proving that tailings waste can substitute cement in concrete mixes and produce an environmentally friendly concrete.