The influence of slurry viscosity on hydrocyclone performance
type: CreativeWork
description: Many of the empirical hydrocyclone cut size models available consider the feed solids content to be an important variable in determining the efficiency and resultant classification. However, feed viscosity as a whole is admittedly a more accurate variable to consider as it can be affected by many factors, including solids content, particle size distribution, particle size, mineralogy, pulp chemistry, particle shape and carrier fluid temperature. Earlier theoretical models did try to incorporate slurry viscosity but were developed for very low solids content systems due to the difficulty in measuring slurry viscosity at higher concentrations. Current hydrocyclone models being applied in industry have difficulty in predicting rheological fluctuations at constant solids content, for example with an increase in feed clay content. Investigations, focussed on expanding the studies of previous researchers in this area, were conducted. Experiments involved the design and operation of two test rigs incorporating three hydrocyclone sizes (75,100, 165 mm), with two different ore types (platreef ore, copper ore) from a secondary stage operation used as the feed material. A change in relative viscosity was investigated by altering the viscosity of the carrier fluid (water) by the addition of sucrose, and modification of the slurry temperature. Hydrocyclone feed flow rate and solids content were also modified. A custom made on-line tube rheometer allowed viscosities of feed concentrations of up to 43% (by vol.) to be measured over a range of shear rates (200/s to 1500/s). The slurries under investigation were found to be settling in nature, and therefore a decision was made to exclude data below the critical settling velocity of the tube. Rheological characterisations revealed both ore types exhibited Bingham plastic behaviour. A concentration versus viscosity relationship was determined from the rheological data and the resultant viscosity values were then linked to hydrocyclone…
abstract: Many of the empirical hydrocyclone cut size models available consider the feed solids content to be an important variable in determining the efficiency and resultant classification. However, feed viscosity as a whole is admittedly a more accurate variable to consider as it can be affected by many factors, including solids content, particle size distribution, particle size, mineralogy, pulp chemistry, particle shape and carrier fluid temperature. Earlier theoretical models did try to incorporate slurry viscosity but were developed for very low solids content systems due to the difficulty in measuring slurry viscosity at higher concentrations. Current hydrocyclone models being applied in industry have difficulty in predicting rheological fluctuations at constant solids content, for example with an increase in feed clay content. Investigations, focussed on expanding the studies of previous researchers in this area, were conducted. Experiments involved the design and operation of two test rigs incorporating three hydrocyclone sizes (75,100, 165 mm), with two different ore types (platreef ore, copper ore) from a secondary stage operation used as the feed material. A change in relative viscosity was investigated by altering the viscosity of the carrier fluid (water) by the addition of sucrose, and modification of the slurry temperature. Hydrocyclone feed flow rate and solids content were also modified. A custom made on-line tube rheometer allowed viscosities of feed concentrations of up to 43% (by vol.) to be measured over a range of shear rates (200/s to 1500/s). The slurries under investigation were found to be settling in nature, and therefore a decision was made to exclude data below the critical settling velocity of the tube. Rheological characterisations revealed both ore types exhibited Bingham plastic behaviour. A concentration versus viscosity relationship was determined from the rheological data and the resultant viscosity values were then linked to hydrocyclone…
author: Waters, Jason G
language: eng
date published: 2012
date modified: 2026-07-22T22:22:42Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Centre for Minerals Research

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/14417