This paper aims to explore the potential use of flue gas desulfurisation gypsum (FGDG) and phosphogypsum (PG) into cemented paste backfill (CPB). The mechanical strength of CPB and the binder paste properties (i.e., hydration heat, hydration evolution, acid erosion resistance, and leachability) were investigated experimentally. The results revealed that the addition of FGDG and PG significantly improved the mechanical performance of CPB by lowering the porosity and increasing the formation of ettringite (AFt) in the early stages. The normalized hydration heat of blended binders was decreased significantly due to replacement of cement with mineral admixtures (i.e., fly ash [FA], FGDG, PG, and quicklime). Dissolved FA decreased the Ca/Si ratio of blended binders, promoted the incorporation of aluminium into the C–S–H gel, and increased the acid erosion resistance. Moreover, the addition of quicklime led to the generation of extra portlandite, which improved the acid erosion resistance. Heavy metals were immobilised by hydration products, and the addition of quicklime further enhanced the stabilisation. The novel binders (SPC + FA + FGDG/PG + quciklime) show prospective application in CPB technology.

本文旨在探讨将烟气脱硫石膏（FGDG）和磷石膏（PG）用于水泥浆回填（CPB）的潜在用途。实验研究了CPB的机械强度和粘合剂的性能（即水合热，水合演变，耐酸蚀性和浸出性）。结果表明，加入FGDG和PG可通过降低孔隙率并增加早期钙矾石（AFt）的形成来显着改善CPB的机械性能。由于用矿物掺合料（即粉煤灰[FA]，FGDG，PG和生石灰）替代了水泥，掺合料的归一化水合热显着降低。溶解的FA降低了混合粘合剂的Ca / Si比，促进了铝在C–S–H凝胶中的结合，并提高了耐酸蚀性。此外，生石灰的添加导致产生了额外的硅酸盐，从而改善了耐酸蚀性。水合产物可固定重金属，生石灰的添加进一步增强了稳定性。新型粘合剂（SPC + FA + FGDG / PG +曲克林姆）在CPB技术中显示出潜在的应用前景。