Degassing in mining refers to the controlled removal of dissolved gases — most notably methane (CH₄), carbon dioxide (CO₂), hydrogen sulfide (H₂S), and radon — from rock formations, groundwater, process fluids, or enclosed mine atmospheres. This process is critical for safety, operational efficiency, and environmental compliance across a wide range of mining operations, including those for bauxite, gold, iron ore, and diamonds. In underground gold mining operations, degassing of rock strata is a routine safety practice to reduce the concentration of combustible gases — particularly methane in carbonaceous ore zones — to below explosive limits. Specialized degassing boreholes are drilled ahead of mining faces to drain gas and reduce outburst risks. In iron ore mines where deep carbonaceous formations may be present, degassing programs are similarly implemented prior to advancing development headings. In mineral processing, degassing is applied to process water or slurries to improve reagent efficiency and flotation performance. For example, dissolved air or oxygen in process water can interfere with cyanide leaching in gold processing plants or affect flotation selectivity in iron ore beneficiation. Degassing equipment such as vacuum towers, degassing columns, and membrane contactors are used to remove entrained gases from process streams. In diamond mining operations involving kimberlite pipe exploitation at depth, degassing may also be needed to manage naturally occurring CO₂ emissions that accumulate in deeper working areas of the mine.
