Electrochemical corrosion behavior and assessment method of anchor bolts in high-salinity mine water

Corrosion of anchor bolts in deep high-salinity mine water threatens the durability of underground support systems. This study investigated the hydrochemistry of mine water from the −1590 m level of Xiling Mine and the corrosion behavior of HRB400 anchor-bolt steel. The water contained 4245.75 mg·L −1 Cl − , with an E h of −458.01 mV and conductivity of 19.05 mS·cm −1 . Larson Ratio values of 106.87–223.67 indicated high hydrochemical corrosion susceptibility. Triplicate polarization tests showed active corrosion without distinct passivation, yielding a mean corrosion current density of (1.83 ± 0.18) × 10 −5 A·cm −2 . EIS spectra were fitted using an R s –( R ct ||CPE) circuit, with a mean charge-transfer resistance of 3645.73 ± 202.78 Ω·cm 2 . Faraday-law conversion and Arrhenius correction gave a static estimate of 0.506 mm·a −1 at 42 °C, while mass-transfer scaling gave 0.634 mm·a −1 under representative seepage conditions. Static immersion tests yielded 0.478 ± 0.016 and 0.477 ± 0.008 mm·a −1 after 14 and 28 days, respectively, differing from the static estimate by 5.54% and 5.81%. SEM–EDS indicated increasingly heterogeneous oxygen-containing deposits and chloride-associated surface products. These results support corrosion assessment of anchor bolts in deep high-salinity mines.