Consideration of the questions: (i) is it feasible to study groups of processes in a generalised way? (ii) to what extent does purpose affect the form of a process model? (iii) are there any significant, novel investig- ations which can be made by computer simulation? (iv) what long-term developments are desirable in extractive metallurgy? has led to some new broad objectives for research in hydrometallurgical process engineering._x000D_
Propositions for grouping processes, developing models for different specific purposes, using a systems engineering approach and developing high technology processes are discussed, and the role of computer simulation indicated by reference to particular projects.