Advances in Engineering Advances in Engineering features breaking research judged by Advances in Engineering advisory team to be of key importance in the Engineering field. Papers are selected from over 10,000 published each week from most peer reviewed journals.
Minerals Engineering Volumes 36–38, October 2012, Pages 21–30
Steven J. Spencer, Ryan Bruniges, Giffard Roberts, Vic Sharp, Alvaro Catanzano, Warren J. Bruckard, Kevin J. Davey, Wen Zhang
Lucas Heights Research Laboratory, CSIRO Process Science and Engineering, Locked Bag 2005 Kirrawee, New South Wales 2232, AustraliaClayton Research Laboratory, CSIRO Process Science and Engineering, Box 312, Clayton South, Victoria 3169, Australia
Minerals Down Under National Research Flagship, Australia
Abstract
A passive acoustic emission (AE) monitoring system has been developed and tested in Australian coal washeries. The system detects naturally occurring stress waves in the pulp and froth zones of a flotation unit, utilising volumetric (hydrophone) and surface (broadband accelerometer) sensing technologies. The analyser has been proof-of-concept trialled on a coal washery Jameson cell. AE signals associated with both hydrophones mounted near and accelerometers mounted on a downcomer are shown to be sensitive to cell process conditions including aeration, feed solids and reagent addition rates. Accelerometers mounted on a Jameson cell downcomer are shown to be particularly sensitive to aeration rate with AE signals containing features that can be interpreted in terms of Minnaert bubble resonance theory. The frequencies of peaks in the Fourier power spectra are in this case used to estimate dominant bubble size and solids loading inside the downcomer. Passive AE monitoring is a promising approach for flotation cell performance on-line monitoring. aº Strong passive acoustic emissions (AEs) detected in a coal washery Jameson cell. aº Passive AE signatures vary strongly with aeration and feed solids rates. aº Single bubble Minnaert resonance theory explains some J-cell AE spectral features. aº Downcomer dominant bubble size and attached solids mass estimated from AE signals. aº Method for on-line estimation of J-cell downcomer bubble size and attached solids.
