Research Advances of Prevention and Control of Hydrogen Sulfide in Coal Mines

Sudden emission and casualty accidents caused by abnormal enrichment of hydrogen sulfide (H2S) in coal mines are becoming frequent increasingly, causing major casualties and environmental pollution. Scholars in various countries have developed various measuring devices for hydrogen sulfide content in coal and rock formations and their calculation methods. The existing prevention and control technologies of H2S in coal mines were summarized in various countries. According to the distribution characteristics, occurrence modes, and emission forms of H2S in coal mines, the prevention and control technologies of H2S in coal-bearing strata, airflow in tunnel, and underground water body are mainly introduced. Analyzed the effects of different ventilation systems on prevention and control of H2S, which include conventional ventilation system, partial homotropal ventilation system, and full homotropal ventilation system. The methods used mainly include neutralization by injecting alkalizer through drilling in coal seams with high pressure, spraying alkalizer in tunnel, attenuation by increasing wind amount, changing the ventilation method, pumping, dredging, and blocking the water that contains H2S as well as comprehensive prevention and control method. The basic agents adopted mainly include sodium carbonate (the mass percentage concentration is about 0.5% ~ 3.0%) and sodium bicarbonate solution, and some basic solution is added by an additive, such as surfactant, Fenton reagent, sodium dodecyl benzene sulfonate, sodium hypochlorite, or chloramine-T. The treatment effect and the main problems of each prevention and control technology are analyzed, and a comprehensive method of prevention and control techniques of H2S in coal mines is proposed. According to current technological level as well as the cost, the effective prevention and control techniques of H2S should take the occurrence, distribution, and emission forms of H2S in coal mines as well as the content into consideration