Developments in the theory of particle mixing

It is shown that there are three components in a mixing process: convection, diffusion and shear. The concepts involved in analysing complete and partial mixtures are examined and a statistically satisfactory expression evolved for the state of a mixture. A number of theories of mixing rate are examined and compared with the few published experimental results, and a new theoretical treatment is offered based on diffusion theory. This is shown to be in at least as good agreement with fact as existing theories, and to provide a better basis for extension to more complex cases.