Research on the law and mechanism of potential pollution of groundwater quality by grouting with cement-based materials.

In mining, the large amount of slurry used in grouting may harm groundwater quality and cause pollution. Therefore, researching the pollution effects of common grouting materials on regional groundwater is vital. A dynamic percolation reaction system was set up, and three sets of percolation tests were conducted for the ungrouted control (W), cement slurry (C), and cement-sodium silicate slurry (CS) groups. Their leachates were analyzed. The study found the following: (1) the slurry's hydration reactions greatly affect ionic contamination in the leachate. (2) After grouting, most ions in the leachate had high initial concentrations but decreased as percolation continued. The ionic concentration trends varied. Cement grouting caused metal ion contamination like Ca²⁺, while CS grouting led to high SO2- 4 levels. The main pollutants' degradation mostly follows an exponential decay model. (3) The leachate was alkaline after grouting, with increased total dissolved solids and reducing properties. Its hydrochemical type changed and gradually shifted towards that of the control group as percolation continued.