Settling and rheology of suspensions of narrow-sized coal particles
- Illinois Univ., Chicago, IL (United States). Dept. of Chemical Engineering
This paper discusses settling rates, yield stresses, and shear-stress/shear-rate dependences which were determined as functions of solids concentration for suspensions in water of coal particles of narrow size fractions. Particles and suspensions are characterized by coal analyses, determination of heating value, solid heat capacity and thermal conductivity, particle size analyses, and determination of densities and maximum packing concentrations for each particle size range. Analysis of the settling data establishes that the usually strong retardation of (hindered) settling due to concentration is compounded by particle shape effects. Shear-stress/shear-rate data for concentrated suspensions of the three larger and relatively narrower sized particles over the broad range of shear rates from about 1 to 10{sup 4} s {sup {minus}1} suggest the behavior to be essentially Newtonian, albeit with a marked particle concentration augmentation. Suspensions of the smallest coal particles of broader size distribution were strongly non-Newtonian, possessing a yield stress at low shear, essentially power-law shear-thinning behavior over the intermediate range and approaching high-shear Newtonian limiting behavior above about 10{sup 3} s{sup {minus}1}.
- Sponsoring Organization:
- NSF; National Science Foundation, Washington, DC (United States)
- OSTI ID:
- 7152166
- Journal Information:
- AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 38:7; ISSN AICEA; ISSN 0001-1541
- Country of Publication:
- United States
- Language:
- English
Similar Records
Stability, rheology and flow of coal-water mixtures: Final report
Rheology of concentrated suspensions and their settling characteristics in vessels having inclined walls. Final report
Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
AQUEOUS SOLUTIONS
CARBONACEOUS MATERIALS
COAL
COAL FINES
DATA ANALYSIS
DENSITY
DISPERSIONS
ENERGY SOURCES
FOSSIL FUELS
FUELS
MATERIALS
MIXTURES
PARTICLE SIZE
PHYSICAL PROPERTIES
SHEAR
SIZE
SOLUTIONS
SUSPENSIONS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES