| 摘要 |
PURPOSE: To provide a cost effective regenerative treatment method for foundry old sand by grinding sand grains to liberate, polish and remove away the useful dead-burnt binders and additive skin fixed to the particles from the dust and removing these binders and the skin by a suction effect. CONSTITUTION: The clay-bound foundry old sand is regenerated. The old sand is packed into a drum 1 arranged at a horizontal axis. Acceleration and deceleration are repetitively applied to the sand grains and the sand grains are polished by overall impact and shearing stresses. As a result, the useful dead-burnt binders and additive skin fixed to the particles are liberated from the dust 2 and are polished and removed away from the sand particles during the treatment. These binders and the skin are removed by the suction effect in control means using a cyclone separating machine 3, a filter 4 or the like. As a result, the amt. of the old sand to be discarded is decreased and a contribution may be made substantially to environmental protection.
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