Method of making concrete sand.

摘要

A method of making concrete sand is provided in which a mixture of medium stones (3), material sand (4), and water (5) is agitated in the inner milling chamber (2) of a first cylindrical drum (1) by rotation of the first cylindrical drum (1). The medium stones (3) are maintained piling to a height equal to 1/4 to 1/3 the inner diameter of the first cylindrical drum (1). The number of rotation of the first cylindrical drum (1) is decreased as the inner diameter of the same increases. The supply of the water (5) is controlled for increase and decrease in precise or approximate proportion to the feeding of the material sand (4). The medium stones (3) are prepared by a novel manner from rubble stones (24) using a second cylindrical drum.