A method and apparatus for blending liquids and granular materials in which an impeller assembly is mounted for rotation within a housing at a lower end of a particles inlet and characterized in particular by circumferentially spaced impeller vanes in outer concentric relation to a series of expeller vanes surrounding the particles inlet and which together propel the solid particles outwardly to intermix with the liquid introduced into the annulus surrounding the impeller assembly, and different selected vane configurations are provided with circumferential portions protruding into the path of counterflow of the slurry from the annulus in order to keep the eye or central area of the impeller assembly dry.