The results of the study of thickening process as a preoperation prior to hydrometallurgical treatment stage in the Arkhangelskoye and Nikolayevskoye deposits gold-bearing ores processing are reflected in the article. It is shown, that regarding the Arkhangelskoye deposit ore with high content of friable minerals that form large quantity of fine size fractions in grinding, flocculants application in thickening is required. In thickening feed ore of the Nikolayevskoye deposit as well as tailings, produced in this ore processing, application of flocculants is not advisable.