17 March 2021
The particular chemical used at the site will be specific to the mineralogy of the ore deposit. [...] In the case of shafts, sealing often includes the placement of crushed rock in the shaft bottom to prevent migration of the fill material into the mine. [...] This allowed for the water that infiltrated or accumulated in the mine to the drain downdip to the entry and hence little water was impounded. [...] This is due to the fact that ferrous oxidation to the ferric state slows as the pH of the solution is lowered. [...] The nature of these loads is a function of the geochemistry of the mining site as well as the physical arrangement of the mining with respect to water and air infiltration to these geochemically active materials.