Mixing is used in materials processing industry with main objective of reducing differences in properties such as concentration and color, between different parts of a system. Shear mixing is sometimes considered as part of convective mechanism. The movement of particles during a mixing operation, however, can also result in another mechanism which may retard, or even reverse, the mixing process and is known as segregation. The importance of segregation on degree of homogeneity achieved in solids mixing cannot be overemphasized. Any tendency for segregation to occur must be recognized when selecting solids mixing equipment. Vertical screw mixers are quick, efficient, and particularly useful for mixing small quantities of additives into large masses of material. Most of the proposed models to determined mixing indices as an indicative of blending homogeneity are based on experimental determination of sample's mean values and variances. The objective of the experiment is to determine mixing indices for solids mixing operation using double cone mixer and V-cone mixer.