Rate of Bitumen Film Transfer from a Quartz Surface to an Air Bubble as Observed by Optical Micro s c o py

Oils from natural deposits and those produced by the petroleumindustry have a very broad range of physico-chemical properties.Viscosity, density, interfacial tension, and surface charge are among the properties which usually have an influence on the selection of an oil recovery technology and the selection of appropriate operating conditions. For example, the density of many oils is similar to the density of water, and their separation from the aqueous phase cannot be realized in a gravitational force field. In such cases, oils must be “filled” with a volume of gas, light solvent, or light solid particles to make them less dense than the processing water. One of the filling procedures is flotation, gas intrusion into the oil phase, a most popular separation technique used in oil recovery from aqueous suspensions. Froth flotation is a common separation process for the recovery of oil from oil sands (Miller and Misra, 1982; Oblad et al., 1987) and contam-inated soil (Anderson, 1993; Friend, 1996). In the froth flotation technique, two major separation steps must be accomplished: i) oil release from mineral matter, and ii) oil flotation from the slurry. Durin