Understanding fine ore breakage in a laboratory scale ball mill using DEM

Cleary, Paul W. and Morrison, Rob D. (2011) Understanding fine ore breakage in a laboratory scale ball mill using DEM. Minerals Engineering, 24 3-4: 352-366. doi:10.1016/j.mineng.2010.12.013


Author Cleary, Paul W.
Morrison, Rob D.
Title Understanding fine ore breakage in a laboratory scale ball mill using DEM
Journal name Minerals Engineering   Check publisher's open access policy
ISSN 0892-6875
1872-9444
Publication date 2011-02
Sub-type Article (original research)
DOI 10.1016/j.mineng.2010.12.013
Volume 24
Issue 3-4
Start page 352
End page 366
Total pages 15
Place of publication Oxford, United Kingdom
Publisher Pergamon
Collection year 2012
Language eng
Abstract DEM models of fine grinding in ball and stirred mills have to date almost entirely focused on the motion of the media and their interaction with the mill configuration. For SAG mills, a large fraction of the feed material can now be accurately represented in DEM models. However, for other mill types with much finer feed materials, such as the second chamber of a cement ball mill, the vast numbers of feed particles makes their explicit inclusion in the models prohibitive. However, it is now feasible to model a periodic section of a laboratory scale ball mill and include the coarser end of the ore size distribution directly in the DEM model. This provides the opportunity to better understand the effect of media on the interstitial bed of powder and of the effect of the powder on the media. The effect of the powder fill level, which is varied between 0% and 150% of the pore space in the media charge, is explored. The distribution of the powder, its effect on power draw and the way in which it contributes to the pattern of energy utilisation is assessed. The simulation results are compared with experimental results from a test at similar ball loading and rotation rate and for several size fractions of ore at a range of powder fill fractions. Tracking the collision histories of specific ore particles within the charge allows estimates of the probability (per unit time) of collision between media and ore particles (the “Selection” function) and of the intensity of each collision which can be used to estimate the severity of breakage using the JKMRC breakage model (the “Breakage” function). The energy spectra indicate that for a typical ore, only very few collisions are large enough to cause damage to the body of each particle. This provides an estimate of the energy efficiency which is less than 10% at even the best operating conditions.
Keyword DEM
Breakage
Ball mill
Fine grinding
Comminution
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Special issue: Comminution (February-March)

Document type: Journal Article
Sub-type: Article (original research)
Collections: Julius Kruttschnitt Mineral Research Centre Publications
Official 2012 Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 15 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 15 times in Scopus Article | Citations
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Created: Thu, 19 May 2011, 15:02:27 EST by Karen Holtham on behalf of Julius Kruttschnitt Mineral Research Centre