Thread: cullet shortage
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Old 04-27-2019, 03:54 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
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My impression with the Spectrum cullets is a bit different. I feel strongly that it never really completed the melt cycle before being pulled from the tank. It appeared mostly melted but was still in an outgassing mode. The boron in that instance was quite active and went after any fireclays or alumina parts.

Boron by itself is not a monster but if you couple it up with barium it can really cause issues. American refractories of typical composition from 76-90 percent alumina are pretty receptive to degradation. The 76 composition is typical of a mullite mix and the 90% is typical of several crucible manufacturers.

But because it processed out of the furnace prior to true fining, it indeed saved money but the chemical reaction resumed once the stuff was melted a second time. The Flake, which Oceanside is currently offering up is stuff I suspect to have boron present. Cristalica has the issue of containing both Boron and barium. They said they had lowered the boron content but all along their literature indicated the amount to be constant. The real problem there, as I see it is trying to ram 7 tons a day through a system designed to process five. Grade B indeed. Whether any of these companies can meet volume demand will be the big issue.
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