Recovery of Precious Metals from Secondary Feed Sources, e-Waste and i-Waste.
The availability, at reasonable cost, of some raw materials has become a political and economic concern for both governments and businesses alike. Due to their specific physical and chemical properties precious metals are used in electronics and are staples of catalytic processes whether industrial, agricultural or medical. The precious metals gold (Au), silver (Ag), platinum (Pt) and palladium (Pd) are internationally recognized as forms of currency under ISO 4217 and remain important as investment commodities. The European Union assessed a total of 41 materials for criticality and 14 (known as the EU14 critical materials) have been identified as critical of which the platinum group metals (PGMs), i.e. ruthenium, rhodium, palladium, osmium, iridium, and platinum are identified. With recent increases in the value of PGMs and an ever increasing focus on the sustainable use of metals, interest in the processing of secondary feed material sources and metal-bearing residues has substantially increased. Generally, the secondary feed material and metal-bearing residues are wastes or by-products of the metallurgical industries. These are usually in the form of slags, sludges, dusts, tailings and by products generated either in the end or as intermediate product. Due to the high demand and value of these materials, and for some the scarcity, there is increasing pressure on our resources and a growing need to understand the potential for recovery of PGMs, Ag and Au from various waste streams.
The aim of the project to develop an innovative method to treat precious metal wastes and reduce both water consumption and potential environmental hazards. The project is split into four distinctive areas.
Area 1. Selective leaching studies – Initial work will look at developing innovative leaching processes for the recovery of precious metals. This will potentially involve pressurised systems, ultrasonics and electrochemical methods alongside traditional chemical leaching methods.
Area 2. Metal ion extraction studies - Initial work will look at commercially available ion exchangers/scavengers which can actively extract softer heavy metals from solution. Tests will be carried out to determine the capacity, kinetics and thermodynamics of the extraction mechanism. Synchrotron techniques will be utilised to directly understand the mechanism by which the metals interact with these solid phase extractants and facilitate the development of a surface complexation model.
Area 3. Dynamic testing and modelling – Work will be carried out to determine dynamic operation parameters of the recovery process. A hydrodynamic model will then be developed to facilitate scale up of the recovery process.
Area 4. Electrochemical recovery process – Once an enriched stream of precious metals has been created the precious metals will be recovered by electrochemical methods. Work will be carried out to both develop new electrodes for the electrodeposition processes as well as adapting the electrolyte to maximise the recovery process.
Candidates should have a First Class Honours degree in chemical engineering, physics, material science, or a related discipline.
This project is open to competition for an EPSRC Doctoral Training Grant (DTG). Closing date for applications: 27 November 2015
UK candidates would be eligible for fees and stipend at the standard EPSRC rate.
EU candidates would be eligible for fees only (no stipend).
Overseas candidates are not eligible for this funding but are welcome to apply if able to fund the project from other sources.