Beneficiation of Oil Shale by Froth Flotation: Critical Review

Abstract

Oil shale beneficiation by froth flotation hasn't received enough attention in the last two decades. The reason was the economics of the process as well as its environmental impact. However, the recent surge in oil price and recent developments in fine grinding technologies may improve the efficiency of oil shale beneficiation by such process. In this work, oil shale concentration by froth flotation technique was critically reviewed. It was found that most of the work was conducted by conventional mechanical flotation using non-ionic collector such as kerosene. Flotation has more pronounced effect on flotation of low grade oil shale; Almost 95% of ash forming minerals were removed to enrich oil shale concentrate by factor of 2-4 with 60-95 % kerogen recovery and approximately 50-300 % increase in oil yield (L/tonne) .Oil shale retorting economics showed that beneficiation reduced the capital cost for pyrolysis and fractionation by 250 % and spent shale disposal by 270%. However, these saving are offset by the cost of beneficiation (grinding, flotation, and dewatering). Therefore, the key for economical oil shale concentration process is the reduction of fine grinding costs.

Impact of cationic-anionic surfactants on selective oil agglomeration of oil shale

“…Oil shale is a sedimentary rock that contains insoluble kerogen as a combustible organic component. It is considered as the second largest fossil fuel deposit worldwide (Tissot and Welte, 1984;Hruljova et al, 2013;Al-Thyabat et al, 2014). Recently oil shale is assumed to serve as alternative energy due to great lack of energy (Larsen et al, 2000;Savest et al, 2009).…”

Beneficiation of oil shale by froth flotation

“…However, until now, only a few articles have concentrated on oil-shale flotation. Thyabat et al (2014) thought that flotation could improve the grade of low-grade oil shale. Altun et al (2009) used ultrasonically aided flotation to improve the floatability of oil shale and concluded that the particulates filling the pores/voids or attached to the surfaces of the larger particles were effectively removed after ultrasonic treatment.…”