Durability characteristics of geopolymer concrete produced using gold ore tailings along with recycled coarse aggregates

The Gold Ore Tailings (GOTs) are one of the major waste materials in the mining sector. The disposal of these tailings could be a problem for human health and a major environmental concern for several years. In this research work, the GOTs were used as an alternative material to the River Sand (RS) in the production of Geopolymer Concrete (GPC). Thus developed GPC samples were tested for its durability characteristics, such as resistance to sulphates and chlorides. The sulphate attack test was conducted by immersing the Conventional Concrete (CC) and GPC samples in 5% Magnesium Sulphate (MgSO₄) solution for various curing periods. In this test, the GPC samples showed a reduction in compressive strength and weight, which is slightly more when compared to CC samples. The Rapid Chloride Penetration Test (RCPT) was also conducted to know the chloride ion penetration in which GPC samples exhibited less chloride penetration when compared to CC samples. Further, the Toxic Characteristic Leaching Procedure (TCLP) analysis showed that the GOTs have very high concentrations of hazardous metals. However, the concentration of Cyanide (CN^-) was minimal in GOTs. In this regard, geopolymerization would be a better method for immobilizing the hazardous metals in GOTs.