| 摘要 |
PROBLEM TO BE SOLVED: To provide a specific gravity screening method for separating contaminants such wood chips including mud having comparatively high density from sand gravel collected as concrete aggregate and to provide a heavy liquid used in the same.SOLUTION: A heavy liquid (12) is used for specific gravity screening to separate materials not suitable for concrete aggregate from collected sand gravel (10) and has larger specific gravity than that of a mixture of the collected sand gravel and water. The components of the heavy liquid are a salt, bentonite, barium sulfate, cement and the like. The heavy liquid consists of an aqueous solution having a specific gravity of 1.1-2.0. In a specific gravity screening method, the heavy liquid (12) is stored in a tank (20), the collected sand gravel is charged into the heavy liquid within the tank and a sedimented material and a floated material among the collected sand gravel in the heavy liquid within the tank can be taken out to the outside of the tank respectively.SELECTED DRAWING: Figure 1 |
