[Bioconversion] Fireball Express!

[AJH]

On Sat, 28 Oct 2006 14:45:53 -0400, Jeff Davis wrote:
>On Saturday 28 October 2006 03:44 am, you wrote:
>> Jeff,
>> There is a process, I forget what it is called, which uses powdered
>> aluminium & steel to weld joints in rail track.
>> Pack it into a mould around the joint and ignite it, job done.
>> Ken
>
>Is it called something like "kermit welding"?
>

Thermite welding. A local track repair man recently used a pile of it
to melt its way down through a speeding camera ;-).

Basically the iron oxide is mixed with aluminium powder and then
fired, the oxygen from the iron oxide reacts with the aluminium
producing a lot of heat, this melts the iron which is heavy and flows
down into the weld former. They are very careful to keep everything
dry as any water in the weld dissociates and hydrogen.

Thermal lances use a similar technique to cut through mixed materials,
basically form a tube and fill it with steel wire, connect an oxygen
supply to one end and light the other, the hot gases that come out
melt through concrete and stainless steel I'm told.

AJH