CH 1 - Burn The Asbestos Gasket / The Aluminum Fire
Apr 15, 2009

CH 2 - Automotive Fires Gasoline or Electrical
Apr 15, 2009

CH 3 - The Blond Hair and The Missing Knife
Apr 15, 2009

CH 4 - The Brown Product Works / Public Service
Apr 15, 2009

CH 5 - A Fool for a Client
Apr 15, 2009


CH 1 - Burn The Asbestos Gasket / The Aluminum Fire
2009-04-15
Burn The Asbestos Gasket

In the nuclear and aerospace industries materials contacting stainless steels, must be certified by a recognized lab, as having total halogen contents below specified levels. The regulation covers virtually everything including, wash solvents, cutting or machining oils, marking pens and adhesive tapes to name only a few. The low halogen levels are intended to minimize the possibility of eventual stress corrosion cracking which leads to stainless steel failures. The initial analytical methods approved by the nuclear regulatory bodies specified an ASTM technique using an oxygen bomb combustion to liberate the halogens that were then measured with an approved chemical analysis technique. We had quite a long conversation with a hesitant purchasing agent who wanted assurances that the approved techniques would be followed with his company's asbestos gaskets and in the end admitted that he was mystified by how we were going to burn his asbestos filled steel gaskets. (We had previously obtained approval for boiling water leaches on non-combustible materials that had been chopped into suitably sized small pieces.)


The Aluminum Fire

A local industry had experienced an explosion and fire in a furnace filled with molten aluminum but blanketed with nitrogen to protect the melt. During the clean up and repair the furnace was found to contain an extremely hard slag like deposit which presented great difficulty in removal and significantly increased clean-up costs. The "aluminum oxide" slag samples presented to our laboratory did not behave as normal aluminum oxides. On closer examination we found a mixture of oxides and nitrides much to the surprise of the engineering staff who thought the nitrogen to be inert with respect to aluminum. Aluminum reacts with nitrogen if raised to a high enough temperature. An electrical arc from a short circuit can provide the temperatures required to start this reaction.