Abstract:By means of analysing the mechanism of blending materials，a general blending efficien-cy madcl was proposed. Applying this general model to an example，a suitable formula of blending effi-ciency whieh is more accurate than those in papers^[2-3] was obtained. Finally, a high-precision optimal combining prediction formula for calculating blending efficiency was proposed.

Key words: blending efficiency  optimal combining prediction  correlation  fluctuation   statistical independence  normal distribution