To efficiently manufacture a large quantity of high-quality crushed sand using crushed stone including a highly hard raw material for the crushed sand by causing a wet ball mill with a cylindrical body which rotates while being pivotal supported on a wheel, to rotate at a specific range of critical velocity.
A raw material for crushed sand is loaded into a charging hopper 2 and then is cut to the optimal feed level using an adjustable feeder. Thus the cuttings are forcibly flown into a forced ore feeder 10 with water and then are loaded into the cylindrical body 13 of a ball mill 1. This ball mill 1 rotates the cylindrical body 13 at 80% or higher to 89% of the critical velocity with the help of a wheel including a drive wheel and thereby, delivers the crushed raw material into a cylindrical sieve 11 attached to a discharge aperture. In addition, the sieved raw material with a diameter of 5 mm or less is sent to a classifier 4 with water and the dust with a size of not more than 0.074 is discharged with an overflow from the classifier 4. Thus it is possible to efficiently manufacture a large quantity of high-quality crushed sand using various kinds of crushed stone including a highly hard raw material for orushed sand.
KAWANAKA TOSHIO
ASO KINJI
