Calciner-Free Green Sand Reclamation by Using Advanced Mechanical Reclamation System

摘要

In most green sand/core sand systems, new sand is usually added as cores, and waste sand is discharged as dust or removed at shotblasts. If their amounts are completely equal, they must be balanced. However, in most cases, amount of entered sand is much larger than lost after shakeouts. This unbalance makes overflowed sand. Unfortunately, overflowed sand has insufficient properties for replacing new sand. Consequently, overflowed sand must be recycled or wasted. Some large foundries reclaim thermally their waste sand as core sand, and other large foundries recycle it for steel making material or cement material. Both methods have various difficulties for small to medium foundries. Therefore, they must waste their overflowed sand for landfill. Moreover, landfill cost is unbelievably more expensive compared to purchase new sand. Authors developed the cutting-edge mechanical reclamation system that is effective for green sand reclamation with eliminating use of calciners. This presentation reports the principle of the system and results of some case studies. The results shows sand reclaimed by this system is usable as alternative to sand reclaimed by thermal system and unused sand. These advantages contribute not only waste reduction but also defect elimination caused by poor quality cores.