Mining pollution control using biogrouting

Resumo

The wind-induced dispersion of waste materials from mining operations results in the dust accumulation around mines, which in turn lead to negative environmental and economical impacts. In addition, the oxidation of sulphidic minerals extracted from mines promotes the creation of sulphuric acid which subsequently promotes the release of a whole range of metals. As a result, Acid Mine Drainage (AMD) contains high concentrations of acid and dissolved metals. When this toxic mixture flows into groundwater, streams and rivers, it gives rise to several environmental problems. Here, in this paper, we investigate the stability and permeability of the sulfide soil in the Angouran mine, the largest lead and zinc mine in the Middle East, by employing a biological process, biogrouting. Angouran mine is subject to a considerable amount of AMD production due to the water penetration in the soil, which is largely deposited by the dust produced from the mine and storage factories. Biogrouting method exploits bacterial hydrolysis to form calcium carbonate. Consequently, calcium carbonate sediments in the form of cement and consolidates the soil. Our findings show that the soil is stabilized through the inhibition of dust dispersion by biogrouting. The biogrout prevents the protrusion of water inside depots and decelerates the formation and protrusion of acidic drainage and latex consisting of heavy metals into the ground.