Patent ID: 8252415
Filing Date: 2012-08-28
Classification: B02C,B03B,B07B,Y10T

Abstract:
1. A sand making apparatus comprising: a crusher configured to crush crushed materials; a first sorter configured to sort the crushed materials obtained from the crusher into coarse particles, fine particles, and powders through air sorting by air blowing and screening by sorting with a screen, the first sorter including a first collection port for collecting the fine particles sorted by the first sorter; a negative pressure collection unit configured to suck and collect at least a portion of the powders sorted by the first sorter; a second sorter disposed between the first sorter and the negative pressure collection unit, the second sorter configured to sort the powders into coarse powders and fine powders by sucking the powders through negative pressure of the negative pressure collection unit so as to transmit the fine powders in a direction of the negative pressure while allowing the coarse powders to be dropped by gravity, the second sorter including a second collection port for collecting the coarse powders dropped by gravity, and wherein an average particle size for sorting the powders into the coarse powders and the fine powders is 20 μm to 75 μm; and a recovering passage configured to mix the coarse powders collected by the second collection port of the second sorter and the fine particles collected by the first collection port of the first sorter, whereby a mixture of the coarse powders and the fine particles is collected through the recovering passage, while the fine powders are discharged in such a manner that the fine powders are sucked and collected by the negative pressure collection unit.