Lead recovery with a purpose

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Lead recovery with a purpose

Postby Doug Coulter » Sat Jun 28, 2014 8:31 pm

Well, between scrounging expert Bill, and a local guy, I've recently gotten my hands on several hundred pounds of sheet lead. I paid the local guy 50% over what the scrap yard would give him, which is less than half what it's worth, still, so all are happy here. But it looked like it'd been in a car crash, dropped from a plane, and then had a bulldozer driven over it a few times for good measure - folded up and interlocked out the wazoo. This is well past what you can just pound out with a hammer - you have to pull and pry apart those pinched pieces first. I'm partway through the process now, so you can even tell this is sheet lead(!). The stuff that's only 1/16 inch thick is easy, but the 1/4" stuff is...not so much. Big prybars and sweat, then hammer.

The need for this and the cerro-safe mentioned under materials became obvious when in a few seconds, the fusor gave me a dose worth a year of professional rad work the other day - to say the least, we think we have a major breakthrough on our hands, but it's one I want to live to tune up even better, so...here we go with the shielding. Sadly, I actually got (estimated) about 5 years worth in about a minute - there was so much it shut down all my data aq gear as well, frying some of it, so that's a guess, but it was about a month ago, and I live on so far. But Not Good. I'm not yet ready to give up the use of my senses to learn things and use cameras in a cave and so on - yet. This is major work out in the sun. But most of this I don't want to cut up till I have a plan for its exact placement (it's a pain to have to solder it back), so I'm doing it where the guy dumped it out.
Lead1.JPG
What a mess. Nicely oxidized for my "safety".

Lead2.JPG
Some better than other.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Lead recovery with a purpose

Postby Ancona » Tue Aug 12, 2014 3:41 pm

Doug,
Ancona here....I've been incredibly busy and don't think it will slow down any time soon, but I may have something better than that ratted out lead sheeting. I recently demolished a structure for my "largest Customer" [you know who they are] and find myself with two sandwich doors from a facility that needed ......well.......lead shielding. That said, these two doors have a lead sheet running right through the middle of them, and only need to be unbolted from one another to recover what is essentially perfectly flat lead sheets of about 3/32" thickness. The larger door is a 36" by 6' 8" and the smaller door is 24" by 6' 8". I also have another structure on the list for later this year that used to be the occupational health facility, to the odds are good I will find a room with wall shielding, and if I'm lucky, a huge lead pan beneath the mud bed supporting the tiles.

Are you shielding for gamma or beta?

Either way, if you want me to, I can contact Conway Southern to see what it would cost to send it your way.
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Re: Lead recovery with a purpose

Postby Doug Coulter » Wed Aug 13, 2014 2:50 pm

Thanks Ancona - Bill has just delivered another ~400 lbs of straight 1/8" lead plates, so I'm good for now - the shipping costs would be nuts. We do keep the scraps and add them to the bullet making stock...
We are shielding from gamma, mostly around the 100keV range. Most of them are less, but there are a few wicked ones at 600k-2Mev that no lead my floor will hold up can stop, from neutron capture in things. I think I'm in a reasonable place to proceed now, if I'm careful and keep the runs short - I have pretty good computer data aq so I don't need real long runs anymore to get what I want.

As for neutron shielding, what a pain. If they are captured by hydrogen, out comes a 2.2 MeV gamma - right where lead loses nearly all absorbtion ability (eg it's not linear, you need more than 4x the thickness to stop a 4x more energetic gamma).
"Soft" (and I use this in the same sense as a cat bulldozer is "soft") gammas around 500-600kev (eg 5x or so hotter than hospitals use for X rays) are emitted when a neutron is captured in boron (other things are worse) after slowing down in a hydrocarbon (plastic) around 8" thick, and that stuff is truly expensive....and leaves you with 500k gammas that even thick lead won't stop very well. You kind of can't win unless you can afford a lot of thick concrete, and are willing to give up the ability to actually watch and observe with the mark 1 eyeballs...I might get there, but have learned so much from my basic human senses while doing this that I'm loathe to give that up. We may pour some thick concrete elsewhere on the property at some point, but even vid cams can't work with high gamma counts - just like film, they get "exposed" and "white out". And frankly, they suck compared to real stereo vision with the eye's dynamic range being so much larger than any camera anyway.

Hopefully, I'll move past the need to see it running to tune it and design better charged particle lenses. I'm well on the way to being done with that part of things now.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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