Rheology of Victorian brown coal slurries: 1. Raw-coal water

✍ Scribed by Fedir Woskoboenko; Stanley R. Siemon; Dennis E. Creasy

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 829 KB
• Volume: 66
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(87)90070-6

✦ Synopsis

Aqueous suspensions of finely ground raw brown coal from Victoria, Australia, have been tested in a Couette viscometer to evaluate their rheological properties. Shear rates covered the range l-800 s-r and median particle sizes were 641 pm. Concentrations up to 0.6 volume fraction were examined. The results were well represented by the two parameter Bingham model. It was found that the degree of non-Newtonian behaviour, as measured by the yield stress, increased as the concentration was increased or the particle size decreased. The yield stress can be directly related to the volumetric solids concentration, particle size distribution and external specific area via a single, physically meaningful parameter ~ the mean distance separating the particles. The power law relationship between yield stress and inter-particle distance can be used to gauge the degree of flocculation of the system. As with non-interacting particle systems, the plastic viscosity of these suspensions increases in a logarithmic fashion as the concentration increases but is independent of the absolute particle size.