Abstract: Field tests are conducted to evaluate the effectiveness of binders (SS-H and SS-E) for solidifying/stabilizing iron (Fe) and manganese (Mn) contaminated soils at a gold mining acid waste collection reservoir. The field-stabilized soils are subjected to the toxicity characteristic leaching procedure (TCLP), pH, dry density, dynamic cone penetrometer tests, and heavy metal speciation analysis. The results indicate that field stabilization using SS-H and SS-E can significantly reduce the leached concentrations of Fe and Mn, with the leached concentrations of Fe and Mn being below the national groundwater quality standard (GB/T 14848—2017, Class Ⅲ). SS-H is more effective in immobilizing Mn, with its leached concentration decreasing from 23 mg/L to 0.02 mg/L. SS-E is more effective in immobilizing Fe, reducing its leached concentration from 34.3 mg/L to 0.04 mg/L. Both SS-H and SS-E significantly improve the strength of the solidified soils. The dynamic cone penetration index of SS-H and SS-E solidified soils decreases by 93.1% and 93.2%, respectively, as compared to the untreated soils. The results demonstrate that both SS-H and SS-E binders are promising in solidifying/stabilizing multi-heavy metals contaminated soils with low pH. After stabilization, the water-soluble Mn fractions in the SS-H- and SS-E solidified soils are reduced from 16.5% to 0.19% and to 0.34% respectively, while alterations in Fe speciation are insignificant.