[FONT="]R J Lee - spheres - high temp[/FONT]
[FONT="]http://www.nyenvirolaw.org/WTC/130%20Liberty%20Street/Mike%20Davis%20LMDC%20130%20Liberty%20Documents/Signature%20of%20WTC%20dust/WTC%20Dust%20Signature.Composition%20and%20Morphology.Final.pdf[/FONT]
[FONT="]Pg 17 [pdf pg 21][/FONT]
[FONT="]Various metals (most notably
iron and lead) were
melted during the WTC[/FONT]
[FONT="]Event,
producing spherical metallic particles. Exposure of phases to high[/FONT]
[FONT="]heat results in the formation of spherical particles due to surface tension
.[/FONT]
[FONT="]Figure 21 [/FONT][FONT="]and
Figure 22 show a spherical iron particle
resulting from the[/FONT]
[FONT="]melting of iron (or steel)[/FONT][FONT="].[/FONT]
[FONT="]Pg 21 [pdf pg 25][/FONT]
[FONT="]Many of the materials, such as
lead, cadmium, mercury and various organic compounds,[/FONT]
[FONT="]Vaporized[/FONT][FONT="] and then condensed during the WTC Event.
[/FONT]
[FONT="]Lead Melting point - 622[/FONT]
o[FONT="]F [328[/FONT]
o[FONT="]C][/FONT]
[FONT="]Boiling point - Vaporization 3182[/FONT]
o[FONT="]F [1,750[/FONT]
o[FONT="]C][/FONT]
[FONT="]http://www.engineeringtoolbox.com/melting-boiling-temperatures-d_392.html[/FONT]