摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the deposited paste by taking out a regenerated coarse aggregate raw material after a concrete scrap is pulverized, introducing into a dry tube mill, pulverizing the paste while selectively stripping a paste matter stuck to the surface of a fine aggregate and separating a fine aggregate by a dry system to remove. SOLUTION: The concrete scrap is heated to >=100 deg.C to make the paste matter easily strippable from the aggregate and dry-pulverized into a particle size <=1.5 times the max. dimension of the aggregate in the concrete. The coarse aggregate is recovered from the pulverized material and the pulverized material having <=5 mm particle diameter is taken out as a fine aggregate raw material, supplied to a dry uniaxial horizontal tube mill or the like, stirred with the addition of an assistant such as balls and diethylene glycol or the like to strip the fine aggregate and the paste matter from each other. Next, the paste matter is splashed and separated by blowing a large quantity of air to the tube mill, collected by a cyclone or the like and the fine aggregate removed in the paste stuck to the surface and the same as a new one is obtained.</p> |