his paper explores the role of Life Cycle Impact Assessment (LCIA) and Environmental Impact Assessment (EIA) in the evolutionary design of minerals processes. Use is made of a modified hierarchical approach to process design, taking into account the specific features of minerals technologies, and the challenges these accord to process synthesis and detailed process design. These include linked reactor-separator combinations, as well as complex recycle structures which are integrated with the selection and operation of waste management technologies. Process synthesis is posed as a design problem with multiple objectives, and consideration is given to how design decisions are informed by valuation choices, specifically where these relate to environmental performance. The discussion is couched in the context of decision support tools which promote the sustainability of the industry, and some guidance is offered to designers on which multi-criteria decision support tools have value as the design evolves from concept to detailed engineering stages. The approach is illustrated for a particular base metals design study. It is demonstrated that combinations of technologies, rather than the usual vendor-specified discrete technology choices, can offer enhancements in both economic and environmental performance, and are thus consistent with the push to more sustainable practices within the resources sector.