Characterization of leachates from mine waste solids and shale ash from the Stuart resource and design of a retort water treatment cell

Abstract

The results from a series of leaching studies on mixtures of Stuart shale ash and mine wastes, with and without added retort water, demonstrate that all leachates are saline, the major salts being the chlorides and sulphates of Na, Ca, Mg and K. The results also demonstrate that the shale ash and the mining wastes are good sorbents for all classes of organics contained in retort water. The studies show that the biodegradation of the sorbed organics is enhanced by the addition of mine wastes. Experiments using a mixture of shale ash and mine waste as a biological filter in a dedicated Retort Water Treatment Cell (RWTC) of only 1 m depth demonstrate that over 80% of the organics in retort water can be removed on a continuous flow basis.