A batch mixing process consists of three sequential steps: weighing and loading mix components, mixing, and discharge of the mixed product.
In batch mixing all ingredients are loaded into a mixer and mixed for the duration until they are homogenously distributed or mixed. The retention time in a batch mixer is normally arrived at based on trials wherein the time required for achieving the desired level of product homogeneity is established. Mixing cycle times can range from a few seconds with high-intensity units to many hours where additional processing like heating or cooling may be involved. The resulting mix is then discharged out of the mixing vessel. Mixer discharge may be rapid, or it may take substantial time, particularly if the mixer is used as a surge vessel to feed a downstream process. Ideally, a mixer should not be used for storage capacity, as the mixer cannot perform operations of storage and mixing concurrently.
The total batch time is the time required for charging the material into the mixer, the mixing cycle time, discharge time.