What are they shredding??

Bert Hickman wrote in news:uKydnU- lqqYOKSXWnZ2dnUVZ snipped-for-privacy@giganews.com:

Pyrophoric, weren't it? Hopefully not depleted uranium, but there are other metals that will ignite in air with just a minimum of heat/friction. Apprently this was the safest way of breaking down these lumps to a smaller size.

--Damon

Bert Hickman Inscribed thus:

Awesome !

"Bert Hickman" schrieb im Newsbeitrag news:uKydnU-lqqYOKSXWnZ2dnUVZ snipped-for-privacy@giganews.com...

Hello Bert,

I guess it was magnesium (alloy).

Helmut

IMHO its a great way to advertise your product on Youtube. Go further where people with blenders stop...

Magnesium casting flash piles? (the pieces broken off of a mag casting, gets placed into a pile with other grinding dust, etc.

OR,there was some folks excavating earth when the rocks they encountered were more than mere rocks. High carbide content (Calcium Carbide?). They were big rock lookin' lumpy things, but I could not tell if it appeared to be a man made amalgam or unearthed that way.

I'm guessing something with a lot of cerium in it. Neither magnesium nor titanium ignite like that when you hack into them, and they burn intense white.

If that's what it is, then basically, they've made the World's Largest Cigarette Lighter Striker.

Tim

That would be my vote too. Whatever it was it can't have been too hot or it would take the temper off the hardened steel tools of the shredder.

Magnesium is a lot harder to ignite than that.

Regards, Martin Brown

Why don't you try reading the thread?

No, that would not have ceased burning. More likely an iron alloy with=20 Lanthanide rare earth content, maybe Lutetium.

Possibly Neodymium. I've machined that and it's spectacular.

Could be. In another video they shred old hard drives and they spark as well.

At the beginning of that segment (about 1:00 in), the worker is dropping something that looks very heavy.

It also looks like slag from forging.

hamilton

I have read that "flints" in lighters and torch ignitors are made of ferrocerium, an iron-cerium alloy.

Maybe those rcklike metal chunks are a titanium alloy. I have heard that titanium was used in many popular smaller flashbulbs back when cameras used smaller flashbulbs, flashbars and flashcubes.

- Don Klipstein ( snipped-for-privacy@misty.com)

I thought flashbulbs used magnesium.

I do remember reading a lot of sources around 30 or more years ago, especially encyclopedias, saying magnesium. I have heard aluminum and titanium to a lesser extent.

(See below - I may be incorrectly remembering mention of titanium, it is starting to look to me more like zirconium, one square down from titanium in the periodic table.)

I have also opened up a fair number of flashbulbs of different brands and at least 4 sizes, plus the ones in flashcubes and flashbars. So far in my experience, I have yet to find magnesium in any of them.

The metal was always in my experience either aluminum or something denser and grayer in color than aluminum or magnesium, and when burned in atmospheric air burned in a way closer to that of steel wool (including color temperature) than magnesium does, although faster and hotter than steel wool. I cannot be certain what that metal was, but it does appear to me to fit the description of titanium.

One thing that I cannot rule out is either or both of these metals being alloyed to reduce heat conduction to make them easier to ignite.

It appears to me that flashbulbs were more likely to use aluminum if they were larger, moderately older designs, and later small ones were more likely to use the denser grayish metal that may be titanium.

Meanwhile, the "aluminum wool" used in many flashbulbs, in my experience, usually cannot be ignited in atmospheric air by a flame (protective oxide thickens first), but can be ignited by a neon sign transformer. That is why I think it was aluminum and not magnesium.

Aluminum can be made to burn like magnesium does, but not as easily most of the time due to greater heat conductivity and its tendency to form a shielding oxide if it takes more than some fraction of a second to heat it up to its ignition temperature.

The denser, more grayish metal that may be "titanium wool" in my experience is easy to ignite in atmospheric air with a flame.

Wikipedia says magnesium was used earlier and zirconium was used later. That means I may have been incorrect to have mentioned titanium.

I just tried Google - a quickie look is appearing to me to support zirconium over titanium although a US patent mentions titanium, zirconium, magnesium and aluminum - as well as potassium perchlorate and nitrocellulose. (Cover as many bases as possible?)

Trying Google for flahbulb aluminum - I am finding support for what apears to me to be "aluminum wool" to be a magnesium-aluminum alloy.

One cite caught my attention:

That one mentions use of aluminum-magnesium alloy, 92-93% Al, 7-8% Mg. This probably explains why I thought it was aluminum.

- Don Klipstein ( snipped-for-privacy@misty.com)

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Most of them did. This is the first i have ever heard of using titanium=20 in a flash bulb. I want to see some documentation before i buy off on = it. The reaction chemistry is just is not right.

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zirconium,

Thanks for doing the modest research for us all. Also many flashbulbs=20 sported oxygen enriched atmospheres up to 60%. Zirconium is much closer=20 to mischmetal in combustibility.