Laboratory Services: Pulp Rheology (Viscosity
- Determination of slurry sample viscosity at various
- Development of flow curve for slurry sample at various
- Development of correlation between yield value vs.
solids concentration for slurry sample at various
- Characterization of slurry sample as Newtonian vs.
Tests can performed to examine the rheological behavior
of the thickened pulps across a specific shear rate
range. Data correlated include the relationship
between apparent viscosity (Pa-sec) and shear rate (sec-1),
and shear stress (N/m2) and shear rate (sec-1)
at anticipated operating temperatures, grind size, solids
concentrations, residual flocculant, and pH.
The apparent viscosity exhibited by a pulp at a specific
shear rate can be due in part to grind size, solids
concentration, mineralogical composition, temperature,
flocculant dosage and concentration, and pH.
Correlations developed by Pocock Industrial are employed
to characterize the various pulps under test as Newtonian
or non-Newtonian. Further, when the relationship
between apparent viscosity and shear rate varies, the
correlations characterize the fluid within a non-Newtonian
class of fluids.
As required by flow sheet demands for the sizing of agitators,
pipe lines, pumps and screens, viscosity measurements
will be made on Newtonian or non-Newtonian pulps.
Apparent Viscosity (Pascals-sec) will be determined at
various Shear Rates (sec-1). Samples
will generally result from thickening tests, or pilot
- Viscosity Testing
Data collected would allow for the following determinations:
1. Tests to determine apparent viscosity at known
shear rates relative to solids concentration at known
temperature and pH.
2. Data analysis to determine the yield value for
the slurry at various solids concentrations.
3. Determination of the rheological classification
of the pulp (ie. Newtonian vs. non Newtonian).