Size reduction of oil shale by attrition scrubbing and its effect on kerogen content

Abstract

ABSTRACT Size reduction of oil shale is an essential process that allows the liberation of organic-rich constituents from inorganic portions to prepare the oil shale for further beneficiation processes. Grinding by conventional methods was impractical and led to technical and economic problems. In this study, the size reduction of the oil shale was conducted by attrition scrubbing process which seems to be an effective process for cleaning the kerogen surface and its disengagement from associated mineral matter. The statistical design was used to study the significance of soaking time, attrition time, and pH on the product in terms of kerogen and LOI contents. The results indicated that the attrition time is the most significant parameter as the wt% of −2.36 mm reaches about 75% after 120 min of attrition. The effect of pH is insignificant unless the ore has an appreciable amount of carbonate minerals. It is worth mentioning that the kerogen content was improved from 10% to 14% by attrition in acidic media. However, the fine fractions had a low-percentage of loss-on-ignition due to the presence of clay.