Molten steel and molten aluminium

Steven Chastain said:

Several times over the last year I have been asked to comment on a photo of one of the Trade Center Towers. The photo shows a molten flow from one of the windows. The flow falls down along the building. It appears orange and turns to a gray color as it cools.

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Summary: The flow is not steel because the structural steel would fail well below the metling temperature. The flow is likely to be a mixture of aluminum, aluminum oxides, molten glass and coals of whatever trash the aluminum flowed over as it reached the open window. Such a flow would appear orange and cool to a dark color.

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Steve, a mechanical and materials engineer,
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He regularly publishes articles regarding metal casting, machining, and automotive restoration. His “Small Foundry Series” of books are sold in over 40 countries and have become popular “design projects” at many schools and Universities.

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