Occurrence patterns and prevention/control of H2S in mine water

To mitigate the risks of hydrogen sulfide (H2S) emissions in mines, this study systematically quantified the gas–liquid interactions of H2S in mine water under controlled laboratory conditions, focusing specifically on the critical parameters of time, temperature, and pH. Water samples from the Xinzhuang Coal Mine were analyzed, and field tests involving coal seam alkali injection and an absorption spray system were conducted. The results demonstrated that H2S concentrations in water samples increased with ventilation time, reaching saturation levels of 3.66–3.87 g/l within 5 min, significantly higher than in pure water due to precipitation coupling. A temperature increase from 4 to 50 °C caused a 34%–37% decrease in optical density (OD), indicating a substantial reduction in dissolved H2S concentration, with the most pronounced volatilization occurring above 30 °C. Conversely, increasing the pH from 4 to 9 led to an OD surge from 0.25 to over 2.50, confirming enhanced solubility via ionization. In field applications, spray systems with absorption solution concentrations of 1.0%–1.2% achieved H2S removal efficiencies exceeding 85%. For coal seam injection, a formulation of sodium carbonate with quaternary ammonium surfactants proved most effective, reducing H2S emissions with an optimal dosage of 2.4 m3. This study lies in the integrated laboratory and field validation, providing quantitative thresholds for designing efficient H2S control strategies in mining environments.