Abstract: In-situ injection of reactivity geopolymers can effectively seal Acid Mine Drainage (AMD), achieving the goals of
source control and quality improvement of AMD. The reactivity and solidification performance of the grouting material are key parameters for the in-situ sealing of AMD using reactive geopolymers. This study aims to elucidate the synergistic mechanisms of the reactive geopolymers in AMD sealing and conducted experiments including grouting the material curing stability tests, dynamic AMD sealing experiments, and microscopic mechanism characterization. The results indicate that the grouting material exhibits good chemical stability and durability, with heavy metal leaching levels meeting national standards; the erosive effect of AMD can promote the formation of silicate and silicoaluminate substances, then effectively enhance the compressive strength of the nodule body to 6.37 MPa; under dynamic water conditions in an AMD environment, the dynamic blocking rate exceeded 90%. After grouting and blocking reactions, the final effluent pH increased from 3.6 to a range of 6.8 to 8.3. The removal rates of total Fe, Mn, and SO₄^2- were above 98.8%, 52.1%, and 33.3%, respectively. The increase in C-(A)-S-H and N-A-S-H gel products enhanced the ability of the solidified grouting body to solidify and stabilize heavy metals, while SO₄
^2- was converted into more sulfur-containing minerals; The geopolymer was used as a grouting agent injected into aquifers or filling zones, and the cement hydration, the generation of geopolymer, and the formation of the cement polymer were enhanced. hydration, the generation of geopolymer and the formation of hydrophobic film three reaction processes at the same time, under the erosion of acidic mine water, to promote the solidified body surface and the internal C-(A)-S-H, N-A-S-H gel products and Ca₆Al₂(SO₄)₃(OH)₁₂(H₂O)₇, FeS, CaSO₄ and other minerals, and at the same time, curing the heavy metals, formation of colloidal precipitates containing CaCO₃, H₂SiO₃, Fe(OH)₃, and Mn(OH)₂ to meet the needs of green grouting. The synergistic mechanism of “grouting-reactingsolidifying-reducing” of the geopolymer grouting materials was clarified, which provides a scientific basis and practical guidance for the in-situ green management of AMD. 

Key words: in-situ treatment, reactive geopolymer, acid mine drainage (amd), grouting material, synergistic mechanism