This article presents the study of the cross-flow microfiltration of an aqueous calcium carbonate suspension in the presence of dispersant in order to obtain the highly concentrated retentate. In the absence of a dispersant, the cross-flow microfiltration with cylindrical ceramic membrane permitted to increase the CaCO3 suspension concentration from 27 to 36.5%. The retentate concentration is increased markedly in the presence of the dispersant (up to 70%). In the presence of the dispersant, the productivity of cross-flow microfiltration of CaCO3 suspension is almost 30% higher than the productivity of dead-end microfiltration of this suspension at the same pressure of I bar. However, the permeate contamination by the dispersant could not be avoided and a subsequent separation must be provided to purify the permeate.