According to the generally accepted chemical equations for pyrite oxidation, oxygen and water are necessary to initiate acid formation. Exclusion of either reactant should preclude or inhibit acid production. Submergence Submergence relies on several physico-chemical phenomena for success.
Oxygen diffuses very slowly and has limited solubility in water.
For this approach to succeed, a stagnant or no flow condition and relatively thick saturated zone appears critical. This approach is most successful in large mines in flat terrain where ground-water gradients are low, the saturated zone is thick, and aquifers are of large areal extent. Submergence is generally not used in the hilly terrain of Appalachia, where gradients and flow velocities are too great to achieve stagnant, anoxic conditions. In these situations, submergence may be counterproductive and actually enhance the production and leaching of acid products. Submergence or flooding is also applied to prevent AMD from underground mines.