The processes of dividing hydrometallurgical pulps into solid and liquid phases with subsequent washing out of the dispersed solid particles from the solute are very important in the technology of processing ores and concentrates of uranium, lithium, zirconium, and other metals. Flocculation of pulp, i.e., the formation of more or less large and strong aggregates of particles, is accomplished by special flocculating reagents. Their action facilitates dividing and washing out the solid phase from the solute. This article describes the properties and methods of obtaining the most effective flocculents and gives the results of an investigation of the flocculation processes of aqueous, acid, and carbonaceous hydrometallurgical pulps. The article is of interest for a wide circle of specialists working in industrial enterprises, in factory laboratories, and in research institutes studying the concentration of ores and the hydrometallurgy of uranium and other metals.