Abstract: Peirce–Smith copper converting involves complex multiphase flow and mixing. In this work, the flow zone distribution and mixing time in a Peirce–Smith copper converter were investigated in a 1:5 scaled cold model. Flow field distribution, including dead, splashing, and strong-loop zones, were measured, and a dimensionless equation was established to determine the correlation of the effects of stirring and mixing energy with an error of <5%. Four positions in the bath, namely, injection, splashing, strong-loop, and dead zones, were selected to add a hollow salt powder tracer and measure the mixing time. Injecting a quartz flux through tuyeres or into the backflow point of the splashing wave through a chute was recommended instead of adding it through a crane hopper from the top of the furnace to improve the slag-making reaction.