Bilimsel Madencilik Dergisi, vol.61, no.1, pp.31-40, 2022 (Scopus)
To enhance the strength and stability of cemented paste backfill (CPB), many alkaline materials are utilised as replacement or additive to binder or tailings in CPB. However, the effect of these materials on groundwater pollution of CPB needs to be comprehensively investigated. In this study, effects of the utilization of calcitic and dolomitic limestone (CL and DL) as replacement (10 wt.%) to sulphide mine tailings (S-MT) in CPB mixture on the long-term environmental behaviour of CPB were investigated. For this purpose, CPB samples (CPBs) were subjected to dynamic tank leaching tests over 360-days and the analyses of pH, sulphate (SO4 2-) and heavy metals (HMs) on the leachates were carried out. The effects of mineralogy and microstructure on the environmental behavior of CPBs were also examined by X-ray diffractometry and porosity tests. The findings showed that with the utilization of CL and DL, the pH of leachates remained at alkaline levels and the release of SO4 2- was significantly reduced. Furthermore, the denser microstructure in CPBs of CL and DL contributed to be prevented or be remarkably reduced the HMs-releases (except Cu, Mo and Pb). The results reveal that the mechanical properties of CPB as well as its impact on the groundwater pollution should be carefully evaluated.