The Potential of Using Waste Rock and Tailings from Gold Mining in Concrete Production

Abstract

In an effort to lessen the negative effects of mining on the environment and advance sustainability, this study explores the use of gold mining waste rock and tailings (GMWRT) as alternatives to conventional aggregates in concrete production. The study examined the chemical, physical, mechanical properties and water absorption of six concrete mixtures with varied levels of GMWRT (from 0% to 25%). X-ray fluorescence spectrometry and sieve analysis were used to determine the chemical composition and particle size distribution. After 28 days of curing, tests were conducted for compressive strength, flexural strength, and water absorption. The chemical analysis revealed that GMWRT had 80.37% SiO₂, Al₂O₃, and Fe₂O₃, exceeding the 70% pozzolanic material threshold established by ASTM C618. The findings showed that when GMWRT replaced conventional aggregates by 0 to 25%, the compressive strength (CS) went from 31.40 to 17.50 N/mm2, which decreased as the proportion of the GMWRT increased. Although there was a decrease in compressive strength, the values fell within the acceptable range of 17 to 28 N/mm² for various applications. The flexural strength (FS) followed the same pattern as the CS, but it was higher than the required 3.13 N/mm2, which means it can be utilised practicably. GMWRT concrete demonstrated enhanced resistance to chloride attack and reduced water absorption, making it viable for coastal construction. ANOVA and other statistical approaches revealed that the results were important. The analysis reveals that GMWRT can partially replace traditional aggregates. This is excellent for the economy and the environment. This method encourages environmentally friendly construction practices and offers developing nations like Ghana an eco-friendly way to handle mining waste.