Hydrogen gas is most commonly found around which area in a mine?

• A. In and around battery charging stations
• B. Near the coal face
• C. In the airways
• D. Inside the ore body

Answer: (A)

Hydrogen gas in underground mines mainly comes from charging industrial batteries. When lead-acid batteries are charged, water in the electrolyte is broken down into hydrogen and oxygen. This generation occurs at the charging stations, so hydrogen tends to accumulate there, especially if ventilation isn’t sufficient. The coal face is where coal is exposed and broken, and it’s more associated with methane from coal-bearing rock than with hydrogen production. The airways are the passageways; hydrogen would only be present there if released, but its source isn’t there. Inside the ore body nothing produces hydrogen gas under normal operation. So the area around battery charging stations is where hydrogen gas is most commonly found.