A blender apparatus is disclosed which is useful for mixing dry particles with a liquid. In a specific application, dry cement is mixed with water to obtain a cement slurry for cementing oil and gas well casings. The cement particles and water are directed into a disperser unit, in which the water contacts the cement particles at an acute angle. The resulting slurry is passed into a volute casing positioned in a tank. As the slurry swirls within the volute, it develops a vortex action, which continuously circulates the mixture in the tank. The slurry is pumped from the tank and split into two streams. Part of the slurry stream flows directly to a pumper unit, for injection into the well. The remainder of the stream is pumped through a restricting nozzle and back through the volute, to provide a continuous recycle which enhances blending of the dry material with the liquid.