Nicole Uys

Project Title: Developing a process mineralogy approach towards the design of viable process flowsheets with a focus on zinc sulphide processing. 

Research Theme: Mineral Value Chains and Strategic Metals

Supervisors: Prof Jochen Petersen; Megan Becker

Abstract

In order to make future ‘sustainable’ decisions regarding the extracting and refining of metals, one needs to take into account a variety of technical, environmental and economic considerations. These analyses should be grounded in a rigorous and quantitative understanding of different process route options which are underpinned with mineralogy and chemistry. In particular, the storage, disposal or reprocessing potential of product streams, without economic value (i.e. waste streams) should be included as key processing units and not only as an afterthought. 

This project aims to model the different processing options for the metal zinc, taking cognisance that zinc is inextricably linked with the co-production of lead and copper. In addition to silver and gold, Zn-Pb-Cu ores also present critical sources of valuable metals such as indium, germanium, gallium, tellurium. Therefore, the future design of processing facilities needs to take into account how different metals value chains are interlinked and not consider metal production in isolation. 

By considering mineralogy variations from ore/concentrate feed streams, preferential process routes and combinations thereof may arise when analysed in a context of minimising the quantity and toxicity of waste production, and the resilience which making a variety of products can provide to an industry which operates at the margins and is sensitive to market fluctuations. This more holistic evaluation of processes, including waste management, allows for determining where any trade-offs exist and where major inefficiencies exist that can be addressed in the future.