Monday, 20 August 2018

Limitations to the commercial application of biohydrometallurgy for the treatment of base metal sulfide ores

Tank bioleaching is an established and competitive technology for treating refractory gold sulfide concentrates, but despite extensive research and development and considerable expenditure, the technology has had limited commercial application for treatment of base metal concentrates. Heap bioleaching is extensively used for commercial treatment of secondary copper ores but is still to be established for recovery of copper from primary chalcopyrite ores.
In the first keynote lecture at Biomining '20 in Falmouth, Dr. David Dew, of Dewality Consultants Ltd, UK, will review tank bioleach technology developed for treating base metal concentrates and discuss the process and engineering factors that determine the design and scale-up, identifying the limiting factors that affect commercial competitiveness. The development of chemical and bioleaching processes for heap leach treatment of primary copper sulfide ores will also be reviewed identifying challenges that limit bioleach performance.
Dr. Dew feels that the hydrometallurgy component of biohydrometallurgy is often largely ignored at conferences concerned with bioleaching, despite the fact that downstream iron removal, metals recovery and waste disposal are key elements that determine the viability of the overall process. He will review some of the standard methods used for metals recovery and the challenges that are imposed on the overall process, particularly relevant to heap leach operations. Considering the limitations and challenges identified, he will then present a case for opportunities where biohydrometallurgy may add value and identifies focus areas for development.
David Dew has 30 years international experience in the development of biohydrometallurgical processes for application in the extraction of base and precious metals. He joined Gencor Ltd., South Africa, in June 1983; in 1990, as Principal Research Metallurgist, he joined the project team responsible for development of the BIOX Process. He took a lead role in the improvement and design of the bioleach reactors, reducing power costs and establishing a methodology for pilot testing and commercial plant design. He was later appointed Manager Process Development at Billiton Plc responsible for leading research in this area. In 2001 Billiton merged with BHP to become BHP Billiton and David was appointed as Global Technology Manager at the Johannesburg Technology Centre, primarily responsible for technology development for the Base Metals Division. David became an independent consultant in 2012 and formed his own company, Dewality Consultants Limited, which he operates from his home in Cornwall. In May 2018 David joined the College of Engineering , Mathematics and Physical sciences, University of Exeter, as a Postdoctoral Research Fellow working part-time for the Horizon 2020 NEMO project, funded by the European Union. The project re-establishes his links with the Camborne School of Mines, from where he graduated in 1979. 

David's keynote is something to look forward to, but in the meantime I am sure that he would appreciate your views on the future of biohydrometallurgy for the treatment of base metal sulphide ores.
#Biomining20 for the latest updates on the conference.


  1. How about bioleaching application in the urban mining?

  2. The "brick wall" of tank bio-oxidation (needed for sulphide ores) is the (power) cost of oxygen transfer from air to slurry. The only technology which avoids this is the 2NO + O2 ---> 2NO2 reaction. That moves the brick wall to the recovery of NO/NO2 from magnesium nitrate. Gus Van Weert.


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