# Groundwater Mixing Process Identification in Deep Mines Based on Hydrogeochemical Property Analysis
## 4 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{2}{c}{**Piper Diagram**} & \multicolumn{2}{c}{**PHREEQC Model**} \\ \cline{2-5}  & \(\mathbf{R_{\text{a}}(\text{O})}\) & \(\mathbf{R_{\text{b}}(\text{C})}\) & \(\mathbf{R^{\prime}_{\text{a}}(\text{O})}\) & \(\mathbf{R^{\prime}_{\text{b}}(\text{C})}\) \\ \hline C1 & 0.000 & 1.000 & 0.000 & 1.000 \\ C2 & 0.750 & 0.250 & 0.361 & 0.639 \\ C3 & 0.582 & 0.418 & 0.313 & 0.687 \\ C4 & 0.065 & 0.935 & 0.156 & 0.844 \\ C5 & 0.331 & 0.669 & 0.069 & 0.931 \\ C6 & 0.266 & 0.734 & 0.262 & 0.738 \\ C7 & 0.433 & 0.567 & 0.276 & 0.724 \\ C8 & 0.741 & 0.259 & 0.217 & 0.783 \\ C9 & 0.586 & 0.414 & 0.198 & 0.802 \\ C10 & 0.702 & 0.298 & 0.269 & 0.731 \\ C11 & 0.731 & 0.269 & 0.308 & 0.692 \\ C12 & 0.900 & 0.100 & 0.905 & 0.095 \\ O1 & 1.000 & 0.000 & 1.000 & 0.000 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Mixing ratios calculated by piper diagram and modified by PHREEQC model. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{2}{c}{**Cation (mEq/kg)**} & \multicolumn{2}{c}{**Anion (mEq/kg)**} & \multirow{2}{*}{**Hydrochemical Types**} \\ \cline{2-5}  & \(\mathbf{K^{+}\) + Na\({}^{+}\)} & \(\mathbf{Ca^{2+}\)} & \(\mathbf{Mg^{+}}\) & \(\mathbf{HCO_{3}}\) & \(\mathbf{SO_{4}}^{2-}\) & \(\mathbf{Cl^{-}}\) & \\ \hline C1 & 44.80 & 4.00 & 3.95 & 5.68 & 39.60 & 7.56 & \(\text{SO_{4}}\)-K + Na \\ C2 & 12.40 & 5.44 & 6.23 & 6.30 & 12.20 & 5.57 & \(\text{SO_{4}}\)-HCO\({}_{3}\)-K + Na-Mg \\ C3 & 21.50 & 4.62 & 4.45 & 4.62 & 19.70 & 5.81 & \(\text{SO_{4}}\)-K + Na \\ C4 & 37.90 & 4.01 & 3.40 & 4.95 & 33.00 & 6.62 & \(\text{SO_{4}}\)-K + Na \\ C5 & 43.70 & 3.18 & 2.03 & 5.14 & 36.60 & 7.08 & \(\text{SO_{4}}\)-K + Na \\ C6 & 35.00 & 3.53 & 2.74 & 5.86 & 28.50 & 6.08 & \(\text{HCO_{3}}\)-SO\({}_{4}\)-K + Na \\ C7 & 34.10 & 3.24 & 2.10 & 6.24 & 27.10 & 6.01 & \(\text{SO_{4}}\)-K + Na \\ C8 & 12.70 & 5.48 & 5.97 & 6.03 & 11.80 & 6.31 & \(\text{SO_{4}}\)-Cl:HCO\({}_{3}\)-K + Na-Mg \\ C9 & 24.00 & 5.28 & 4.33 & 5.93 & 21.30 & 6.41 & \(\text{SO_{4}}\)-K + Na \\ C10 & 18.70 & 6.84 & 6.50 & 4.84 & 21.20 & 6.04 & \(\text{SO_{4}}\)-K + Na \\ C11 & 14.40 & 7.21 & 6.87 & 4.40 & 18.30 & 5.84 & \(\text{SO_{4}}\)-K + Na-Ca \\ C12 & 8.82 & 2.94 & 4.70 & 9.39 & 4.29 & 2.76 & \(\text{HCO_{3}}\)-SO\({}_{4}\)-K + Na-Mg \\ O1 & 8.41 & 0.53 & 2.22 & 5.16 & 1.73 & 2.32 & \(\text{HCO_{3}}\)-K + Na \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Groundwater chemical ions milligram equivalent (mEq/kg) values and the hydrochemical types of all groundwater samples based on water quality analysis data. piper diagram, as shown in Figure 6, and the changes of ions, pH, and TDS before and after evolution were compared in Figure 7.  
Figure 6: Piper diagram of hydrochemical types evolution in Carboniferous Taiyuan limestone karst-fissure aquifer systems. Figure 7: Durov diagram of the hydrochemical type evolution in Carboniferous Taiyuan limestone karst-fissure aquifer systems. The red point shows the background value. The green points show the initial values of all samples. The blue points show the simulated values of all samples. Before evolution, some groundwater samples of Carboniferous Taiyuan limestone karst-fissure groundwater (e.g., C2, C8, C11, C12) contain considerable Ca\({}^{2+}\) or Mg\({}^{2+}\). The hydrochemical types varied from point to point, resulting from the hydraulic connection between the two aquifer systems. After evolution, most chemical types of groundwater samples (except C12) in the Carboniferous Taiyuan limestone karst-fissure aquifer system transformed to SO\({}_{4}\)-K + Na type, the initial chemical type of groundwater in this aquifer. Simultaneously, the value of TDS increased and the pH decreased. However, the chemical type of the groundwater C12 has evolved to HCO\({}_{3}\cdot\)SO\({}_{4}\)-K + Na type from HCO\({}_{3}\cdot\)SO\({}_{4}\)-K + Na \(\cdot\)Mg type, the same as the chemical type of groundwater in the Ordovician limestone karst-fissure aquifer system.