JPS55164469A - Sand grinding and refining device - Google Patents

Abstract

PURPOSE:To provide a miniaturized sand grinding and refining device by passing sand through a space between inner and outer rotating bodies having abrasives on the walls thereof to allow the sand to be ground by the abrasives, moved upwardly in the space and recovered as refined sand. CONSTITUTION:Sand introduced from an inlet 11 into a bore 6 in an inner rotating body 7 drops onto a bottom surface of an outer rotating body 3 as it is whirled and ground at the surfaces of particles thereof by the centrifugal effect of the inner surface of the inner body 7. The sand at the bottom portion of the outer body 3, which is rotated in the direction opposite to the direction in which the inner body 7 is rotated, springs up as it is whirled by the centrifugal force. Whil the sand rises rapidly in such a manner, a part of abrasives 2 on the inner surface of the outer body 3 and a part of the surfaces of particles of the sand contacting the abrasives 2 come off to form dust. As the sand is ground by the abrasives 2, the sand and the dust advance upwardly through a space defined by the inner and outer bodies 3, 7. The dust having a small mass rises at a high speed into a dust collector, while the sand moves in the mentioned space for a long period time to be ground. The residual dust contained in the sand coming out of the space is floated by agitator vanes 18 provided outside the outer body 3 and guided by a conduit into the dust collector. The ground and refined sand is withdrawn from a discharge port 16.