The Otisca Process:A Pilot Plant Study of Dense Liquid Separation

摘要

The Otisca Process for cleaning coal is based on gravity separation of the feed in a dense medium separator. The parting liquid is a fluorocarbon of low boiling point, low latent heat of vaporization and high density (1.5 g/cm3). The parting liquid is recovered from the product coal and reject and recycled to the process. Due to the low latent heat of vaporization of the fluorocarbon, (77.5 Btu/lb at 77°F) in comparison to water (971 Btu/lb at 212°F) the energy required for the operation of the evaporators is much reduced. Also, no pre-screening of the feed is necessary and the very low viscosity of the fluorocarbon parting liquid results in much shorter separation times than are observed with magnetite suspensions.