What is Mixing, Blending?
“Mixing is the process of thoroughly combining different materials to produce a homogenous product." The mixture is generally a combination of dissimilar materials, e.g. coal ash and cement are blended in a specified ratio to produce Pozzocrete cement. In other cases, a chemically homogenous material may be mixed to produce a uniform lot of a desired weight/volume with consistent particle size distribution, color, texture, and other required attributes, e.g. metal powders produced in 1 ton batch size are blended to a homogenous lot size of 4 tons (or pre-specified quantity) .
The terms "mixing" and "blending" are often used interchangeably, but technically they are slightly different. Blending is a process of combining materials, but blending is a relatively gentle process compared to mixing. In terms of the phase of material, blending is the process of solid-solid mixing or mixing of bulk solids with small quantity of liquid. The terminology mixing is more closely associated with liquid-liquid, gas-liquid, and viscous materials. For the scope of this article and those to follow, we will use the terms "mixing" and "blending" interchangeably.
Mixing and Blending are the most demanding unit operations in the chemical process industries. Industries such as pharmaceutical and foods also rely heavily on mixing and blending technology. Some common examples are as follows:
Chemical Process Industry: Mixing and blending of specialty chemicals, explosives, fertilizers, dry powdered detergents, glass or ceramics, and rubber compounds.