Solidsmixing or solids blending is the operation by which two or more solid materials in particulate form are scattered randomly in a mixer among each other by the random movement of the particles. It has long been one of the most widely used industrial, agricultural, and pharmaceutical processes. However, it has been much less developed both theoretically and practically compared to other processes. Therefore, the practice of art often dominates in the operation and design of the mixing equipment and in the assessment of quality of a mixture. The rapid growth of other process industries has made solids mixing a well recognizedbut not yet well developed operation. A considerable amount