Quantifying mineral liberation by particle grade and surface exposure using X-ray microCT
File(s)Liberation_vf.docx (2.47 MB)
Accepted version
Author(s)
Reyes, F
Lin, Q
Cilliers, JJ
Neethling, SJ
Type
Journal Article
Abstract
Liberation is a key driver in all mineral separation processes as it limits the maximum possible grade for a given recovery. In flotation, this is further complicated by the fact that it is surface exposure of the floatable minerals that determines the ultimate performance. Liberation, grade and surface exposure are commonly quantified using Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (SEM/EDX) analysis of polished sections. The intrinsically 2D nature of this technique can result in significant sampling errors and stereological effects that can affect the quantification of the ore's textural characteristics. X-ray microCT (XMT) is an imaging method that can non-invasively and non-destructively delineate ore fragments in 3D, thus providing an alternative method that eliminates the need for stereological corrections and readily provides surface exposure. A methodology and automated algorithm were developed for extracting this information from images of closely packed particles. By dividing these particles into classes based on both their surface exposure and grade, the extent to which there is preferential breakage of the particles can be assessed—an important consideration if sufficient surface liberation for good flotation performance is to be achieved at coarser particle sizes. Using low energy scanning simple 3D mineral maps can be obtained via XMT, allowing for the assessment of liberation and surface exposure for each mineral species. The methodology was tested on low grade porphyry copper ore as this is representative of the most commonly treated ore types for copper production.
Date Issued
2018-08-15
Date Acceptance
2018-05-23
Citation
Minerals Engineering, 2018, 125, pp.75-82
ISSN
0892-6875
Publisher
Elsevier
Start Page
75
End Page
82
Journal / Book Title
Minerals Engineering
Volume
125
Copyright Statement
© 2018 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.sciencedirect.com/science/article/pii/S089268751830253X
Subjects
Science & Technology
Technology
Physical Sciences
Engineering, Chemical
Mineralogy
Mining & Mineral Processing
Engineering
X-ray microCT
Mineral liberation
Flotation
Stereology
STEREOLOGICAL CORRECTION
MICROWAVE TREATMENT
BOUNDARY FRACTURE
SIZE DISTRIBUTION
MICROTOMOGRAPHY
ORE
QUANTIFICATION
TOMOGRAPHY
BREAKAGE
COARSE
0306 Physical Chemistry (incl. Structural)
0904 Chemical Engineering
0914 Resources Engineering and Extractive Metallurgy
Mining & Metallurgy
Publication Status
Published
Date Publish Online
2018-06-02