Patent ID: 7934599

Claim:
A method for separation of construction waste, in which construction waste crushed to a predetermined size is added to a liquid in a precipitation tank and separated into components in the tank according to specific gravity, in which the liquid has a reference specific gravity lower than that of a component to be recovered but higher than that of the remaining components, such that only the component to be recovered is separated by precipitation to the bottom of the precipitation tank; wherein the liquid is a suspension obtained by diluting a heavy medium in water to have a reference specific gravity; which further comprises the steps of: stirring the cylindrical precipitation tank by rotation using a driving unit such that the medium dispersed in the tank is maintained as a stable suspension; introducing the construction waste crushed to a predetermined size into the precipitation tank; recovering the component precipitated to the bottom of the precipitation by lifting up the component by means of a plurality of rotating plates attached around the inner wall of the precipitation tank and allowing the lifted component to fall down into a recovering unit placed at a central portion of the precipitation tank; gathering the remaining components floating on the suspension at the central portion by pushing with guide plates and discharging the gathered components from the precipitation tank; and measuring the specific gravity of the liquid in the precipitation tank; and adding the medium into the precipitation tank if the measured specific gravity is lower than the reference specific gravity, or adding water into the tank if the measured specific gravity is higher than the reference specific gravity; and the component to be recovered is recyclable aggregate, and the remaining components are impurities having a specific gravity lower than that of the aggregate, and the specific gravity of each component of the construction waste, which is used for determining the reference specific gravity of the liquid, is based on surface-dry density measured in a state where each of the components contained a sufficient amount of water held therein.