Continuous processes must be shutdown and restarted regularly. Results from the study of operating plants showed potential value for computer simulation of the shutdown and startup of stirred tank leaching reactors. Simulation allows operational variables such as feedrate, and process variables such as the dissolution kinetics to be altered to establish trends in behaviour. Results are presented for the start- up of a cold, empty, single stirred tank reactor, in which three solids are leached at elevated temperature at steady state._x000D_
Increasing the average temperature in the reactor during startup did not change the fraction of 'valuable' solid dissolved in the first product but it did increase the fraction of slow dissolving (impurity) solid dissolved.