Reclamation of mine tailings using natural peat

摘要

This work was carried out on tailings from the Greens Creek Mine,Alaska.Establishment of vegetation on the Greens Creek Mine tailings deposit is planned to take place at closure of the mine,using natural peat as soil.The Greens Creek Mine tailings are silt-sized and composed primarily of pyrite,dolomite,quartz,and barite.Hecla Greens Creek Mining Company would place an engineered four-layer soil cover over the tailings disposal facility to minimize the amount of air and water that might enter the tailings after permanent closure.The closure plan for the tailings disposal facility at Greens Creek prescribes an engineered soil cover specifically designed to reduce available oxygen below the cover in the tailings.The cover is primarily designed to prevent diffusion of oxygen in a vapor state into the tailings.The water-saturated layer incorporated into the proposed cover design is intended to limit the flux of oxygen into tailings to that which can be dissolved in water and infiltrated.Ultimately,the rate of water flux through the cover at closure would determine the rate of oxygen ingress to tailings,which in turn would dictate the rate of pyrite oxidation.Peat from bogs represents a vast renewable source of organic matter.Peat bog is near the tailings disposal facility of Greens Creek Mine.Peat cover materials are beneficial in the provision of a top cover for the introduction and maintenance of a vegetative cover.