Imperial College London
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ProfessorStephenNeethling

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Minerals Processing
 
 
 
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Contact

 

+44 (0)20 7594 9341s.neethling

 
 
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Location

 

RSM 2.35Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Reyes:2019,
author = {Reyes, F and Cilliers, JJ and Neethling, SJ},
pages = {3985--3994},
title = {Quantifying mineral liberation by grade and surface exposure using X-ray micro-tomography for flotation processes},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - 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 micro-Tomography (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 designed for extracting this information from images of closely packed particles, thus allowing samples containing a large number of particles to be assessed. The main drawback of XMT is that, unlike SEM/EDX, it cannot directly measure the mineralogy of the sample, instead producing a 3D X-ray attenuation map. We therefore also present an algorithm for calibrating the thresholding of the XMT images based on SEM/EDX images of sections through the same sample, thus allowing the liberation analysis to be carried out on a 3D mineral map in which the uncertainty in the mineral assignment is small and statistically quantified. The methodology was tested on low grade porphyry copper ore as this is both an industrially relevant and traditionally difficult system to quantify using XMT due to the similarity in the X-ray attenuation of the sulphide species, especially the pyrite and chalcopyrite. As each 3D volume imaged contain 100-1000s of grains, large data sets can be readily produced. By dividing these particles into classes based on both
AU  - Reyes,F
AU  - Cilliers,JJ
AU  - Neethling,SJ
EP  - 3994
PY  - 2019///
SP  - 3985
TI  - Quantifying mineral liberation by grade and surface exposure using X-ray micro-tomography for flotation processes
ER  -
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