University of Exeter
College of Engineering, Mathematics and Physical Sciences
ESF Minerals Engineering and Applied Mineralogy PhD Studentship
Project title: Characterisation of arsenic occurrences in complex sulphide ore deposits in Cornwall and process options for its removal from concentrates
Three-year studentship: Tuition fees (UK/EU) and an annual maintenance allowance at current UK Research Council rate. This award is part funded by the European Social Fund (ESF) and is only open to EU Nationals.
Deadline for applications: 1 July 2011
Location: Cornwall Campus, near Falmouth
Primary supervisor: Dr Richard Pascoe
Secondary supervisors: Dr Robin Shail (University of Exeter) and Dr Colin Wilkins (University of Plymouth)
Complex sulphide ore deposits containing copper, zinc, tin and tungsten have been found in recent exploration conducted by Western Mining Ltd in Cornwall. The metal grades encountered are encouraging and could result in a resumption of commercial metal mining operations. However, the common occurrence of arsenic minerals potentially reduces the commercial viability of extracting these ores unless they can be effectively separated by mineral processing.
Little is known about the process mineralogy of these complex sulphides. Preliminary work carried out at CSM has identified a range of copper sulphides, sphalerite, cassiterite, wolframite, fluorite, pyrite and arsenopyrite (main source of arsenic) in core samples. The first part of the research will be to characterise complex sulphide samples. Techniques such as QEMSCAN (automated scanning electron microscopy) and the electron microprobe will be used to identify minerals, determine mineral associations and grain sizes.
The focus will then turn to processing options. The occurrence of the zinc ore mineral, sphalerite, with arsenopyrite represents a significant processing challenge. In the conventional froth flotation separation process both minerals would be floated together following removal of a copper-rich product. An arsenic contaminated zinc concentrate would not be readily saleable and therefore revenue would be lost. The literature provides no solution to this problem and significant research will be required to test combinations of treatments and reagents to find an effective separation method. The facilities available at CSM include equipment to measure mineral surface properties (zeta potential), prepare samples and undertake the froth flotation experiments. A combination of elemental analysis and mineralogy will be used to evaluate the separation methods.
It is possible that conventional methods including gravity separation and froth flotation may not provide the best solution. Hydrometallurgical techniques are increasingly being considered for complex sulphide ores containing elements (such as arsenic) that have a detrimental effect on the conventional process. Bacteria may be used to help oxidise sulphides in this type of ore increasing their solubility in sulphuric acid. Arsenic may be dissolved but then on combination with iron may form an insoluble (stable) iron arsenate.
This research focuses on developing an effective methodology for treating complex sulphide ores containing arsenic. It is of direct commercial relevance for Western United Mines Ltd and the technologies developed would have a worldwide commercial application.
For informal enquiries contact Dr Richard Pascoe at [log in to unmask]
Application criteria:
Applicants should have or expect to achieve at least a 2:1 Honours degree, or equivalent, in either Minerals Engineering or Geology.
How to apply:
To apply, visit www.exeter.ac.uk/postgraduate/money/studentships/application and complete the online web form. You will be asked to submit some personal details and upload a full CV, covering letter and details of two academic referees. Your covering letter should outline your academic interests, prior research experience and reasons for wishing to undertake this project.
This award is part funded by the European Social Fund (ESF) and is only open to EU Nationals.
For general enquiries please contact Liz Roberts at [log in to unmask]
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Geo-mineralisation is administered by the Mineral Deposits Studies Group (UK)
(www.mdsg.or.uk)
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