Contact angle of water on iron ore fines: Measurement and analysis

The relative contact angle (θRCA) for seven iron ore fines was measured by using Washburn Osmotic Pressure method under laboratory conditions. By choosing cyclohexane as the reference that can perfectly wet iron ore particles, the relative contact angles were measured and varied from 57° to 73°. With the volume % of goethite (φG) as the variable, a new model for relative contact angle was developed. The expected relative contact angle for pure goethite is about 56°, while that for goethite free samples is about 77°. Physical properties, such as surface morphology (SMI) and pore volume (Vpore) can influence the relative contact angle. The φG can be expressed as a function of SMI and VPore. Thus, we inferred that the relative contact angle is a function of φG for the iron ores used. The measured relative contact angles were found to be in good agreement (Radj 2 >0.97) with the calculated ones based on the research from Iveson, et al. (2004). Comparing with the model developed by Iveson et al.(2004), the new model for contact angle proposed in this paper is similar, but more detailed with two meaningful physical parameters. The modification of physicochemical properties on iron ores would be another topic in the further study on granulation