Mercury poisoning as a mining hazard

Abstract

Although the domestic resources of shale oil are large, there has been some question regarding the magnitude of the energy subsidy that must be committed in order to extract the contained oil. This study shows that for a 50,000-bbl-per-day, modified in situ extraction facility in 20-gal-per-ton Green River Shale, the energy yield is about 8.6 times the energy subsidy and that about 21% of the in-place oil can be thus recovered. If the mined-out shale is retorted at the surface rather than being discarded, the recovery factor rises to 37% and the net energy ratio should rise significantly as well. It is difficult to compare these figures with those for aboveground retorts because oil burned in place for retorting never enters the energy accounts. However, the resource commitment per unit of recovered energy is more easily compared and is essentially indicated by the reciprocal of the recovery fraction.