| 摘要 |
A reclaiming system for used foundry sand containing a sodium silicate (water glass) binder. The resulting chunks of sand and binder are disintegrated by mechanical crushing in a water wash. A primary slurry containing discrete particles of sand and both dissolved and suspended binder is conveyed to a settling tank where the sand settles from the slurry. The heavier particles of sand are removed by a ladder conveyer, which allows liquid to drain from the sand as it is being elevated. The sand is dried in rotary drum dryers, being subjected to a constant flow of heated air. The remaining secondary fluid, containing particles of binder, is directed to a centrifugal separator, where the suspended materials such as binder particles are removed from the liquid. The liquid is then recirculated in the system, eliminating discharge of liquid or the need for substantial replenishing of liquid during the process.
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