Evaluation of geochemical behaviour of flooded cemented paste backfill of sulphide-rich tailings by dynamic-tank leaching test

This research elucidates the geochemical behaviour of cemented paste backfill (CPB) of sulphide-rich tailings (S-rT). The dynamic-tank leaching test was performed on the CPBs for up to 360 days. The CPBs with the alkaline industrial by-products (AIPs) produced relatively lower acidity, Ec and SO(4)(2-)than the Control. The AIPs replacement appeared to considerably mitigate the release of heavy metals (HMs) including As. Only Mo and As in CPBs of AIPs exceeded the limit-values for ground-water. These findings demonstrated that a suitable CPB mixture design to control the release of all HMs in CPB is of practical importance for ground-water quality.

Automated summary

This study revealed that replacing alkaline industrial by-products can significantly mitigate the release of heavy metals in cemented paste backfill (CPB) of sulphide-rich tailings, highlighting the importance of a suitable CPB mixture design in controlling the release of heavy metals for groundwater quality.