Richardson and Zaki (1954) formulated a correction function for determining the sedimentation velocity of a suspension of particles on the basis of the velocity of a single particle not subject to hydrodynamic and electrostatic forces. The Reynolds number for microparticles is less than 0.25, so the Stokes equation can be used to calculate their terminal velocity. The exponent in the Richardson and Zaki correction function is n = 4.65, independent of particle size. This paper describes experimental research with calibrated silicon oxide (SiO2) particles in which the value of the exponent of the Richardson and Zaki correction function was found to be inversely dependent on the size of the microparticles.