Development of an On-line Flow Rheometer for Mineral Slurries

Abstract

This paper reports on the development of an on-line flow rheometer for characterising the rheological behaviour of settling mineral slurries. The instrument is a modified concentric cylinder viscometer in which the slurry is continuously circulated to keep the particles in suspension. The rheometer is designed based on the fundamentals of helical flow, which is the combination of tangential Couette and axial annular flows, and thus satisfies both the basic requirements of viscometric principles and the restrictions caused by the heterogeneous nature of the material. A strong emphasis is placed on developing a correct and accurate method for extracting fundamental rheological properties from the experimental data, without relying on any empirical calibrations or corrections. The data reduction procedure developed is firmly based on the theory of helical flow and has been extensively tested and validated with model fluids of different rheological behaviour. Testing of the flow rheometer and the data reduction method is still progressing with real slurries, but the results obtained so far have strongly indicated the practical usefulness of the instrument for continuous on-line measurements of the flow properties of settling slurries.

Keywords:

• Flow rheometer
• on-line viscometer
• mineral slurry
• settling slurry
• rheological characterization
• helical flow

Additional information

Notes on contributors

Q. D. NGUYEN

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