Spontaneous Bubble Nucleation on Bitumen
In Canadian oil sands processing,flotation is used to recover liberated bitumen droplets from oil sands slurries.Similar to conventional mineral flotation practice,a fundamental limitation of recovering bitumen from low grade oil sand ores is its slow and ineffective aeration of the liberated small bitumen droplets.Gas nucleation and cavitation could provide better mechanisms for accelerating bitumen-bubble attachment.A research program was undertaken to examine factors affecting spontaneous bubble nucleation on bitumen surfaces.The results demonstrate that surface hydrophobicity and existence of gas nuclei in process water play a critical role for bubble nucleation.While there are more bubbles nucleated on highly hydrophobic silanated glass surfaces than on moderately hydrophobic bitumen,bubble nucleation on clean hydrophilic glass surfaces is negligible.Heating process water up to 85～95℃(as used in commercial operation) or boiling tap water prior to gas nucleation tests is shown to remove sufficient amount of gas nuclei existing in the water,thereby drastically reducing the number of bubbles nucleated on bitumen.Enhancing gas nuclei formation in hot process water is identified as a promising strategy to improve bitumen-bubble attachment during oil sands conditioning,and hence to increase bitumen recovery from low grade ores.
Bitumen Oil sands Bubbles Gas Nucleation Flotation
Z.A.Zhou R.S.Chow Z.H.Xu J.H.Masliyah
Alberta Research Council,Edmonton,Canada Dept.of Chemical and Materials Engineering,University of Alberta,Canada
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
4318-4327
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）