PLATIRUS has just released the Environmental and Economic assessment of Separation R&I chemistries and technologies.
This review looks at the use of different methodologies for separating PGMs from the leachate materials developed in WP3. The development of these different processes reflect the expertise of each of the involved research partners. Early review of these methodologies for their impacts on the sustainability rating of the PLATIRUS process is critical to ensure that the processes adopt chemistries that comply with regulations (REACH and RoHS), processes and equipment are not energy thirsty and the scale-up design does not require excessive volumes of materials. These aspects of the methodologies developed are examined here, using economics and greenhouse warming potential as the two key parameters for comparing early development sustainability. Further sustainability assessments of the technologies will be incorporated into a matrix tool.
The results indicate that a combined separation process utilising both solid phase extraction and liquid-liquid extraction could be optimal in order to balance the energy and materials consumption, whilst optimising separation efficiency. The use of solid phase extraction is a relatively simple process, with low energy demands and provides the opportunity to preconcentrate the PGMs in the eluent. However, separation efficiencies are currently low. But this technology provides an option to reduce the volume to be treated by liquid-liquid extraction. Using the eluent from the SPE, the process efficiency of a LLE is improved, reducing the volume of reagents, the operational time and the energy requirements of the technology.