Foaming Lead

[Rcmaveric]

When I first started casting bullets I bought about 25lb of lead off ebay but obviously that wasn't enough so I started looking for lead source and took one of my smaller motorcycle battery apart and melted lead plates over propane stove outdoors in old pan, I had respirator rated for fumes and it smelled bad before I put it on but nothing horrible happened except it was such such a mess with way too much junk and not enough lead I decided against it in the future and than I read all the warnings on forum. Once in a while I would start conversation with friends about that I cast my own bullets and was quite surprised by the number of people who told me how they took batteries apart in childhood and melted lead over fire in tin cans. Apparently it was normal activity for kids who spend their days outside playing back then different country, different time.

I want to say at some point before i was born they change the ingredients of whats in batteries. I was reading about how it used to be dangerous, but not unsafe. Now during lead reclamation the lead off gass chemical warfare agents. I forgot which one but its a bad one. Thats what I have read. Has to to do with battery acid reaction with mineral (i want to say potassium) and arsenic in the lead (shooting from the hip here so dont quote me).

I would asume if someone put forth the effort to clean it should be safe enough to handle. If and thats a big if, thats what it was from.

I would just melt it down and purify it again. I have a hard time letting lead go. A couple handle fulls of sawdust and let it simmer for about 10 to 15 minutes

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[mvozz]

Just thought it would be helpful if you could see the difference of the ingots I made. One is obviously my problem child and the other is one of several I made that day. I am just not comfortable melting this down again. My concern is all about the safety of melting something with unknown metal in it. I have plenty of lead so loosing this won't impact my supply dramatically. I would think better safe than sorry unless someone can assure me that it would be OK to remelt it.

[ulav8r]

I would be tempted to remelt and flux several times. Just the foamy ingots, keep molten for about 15 minutes stirring continously with a cedar limb. If the bubbles clear up, use it for plinking bullets. If not, sell it to a recycling center or cast into sinkers and sell or use them..

[Peregrine]

mvozz, user BNE on on this forum will test samples of alloy for you with x-ray florescence for the extremely reasonable fee of a pound of alloy per sample tested or so. I have never personally used his services but many here have and been extremely pleased with the experience.

Please contact him and come to an arrangement, I for one am extremely curious what is going on with that alloy and it's your best bet to figure it out.

[Peregrine]

I want to say at some point before i was born they change the ingredients of whats in batteries. I was reading about how it used to be dangerous, but not unsafe. Now during lead reclamation the lead off gass chemical warfare agents. I forgot which one but its a bad one. Thats what I have read. Has to to do with battery acid reaction with mineral (i want to say potassium) and arsenic in the lead (shooting from the hip here so dont quote me).

I would asume if someone put forth the effort to clean it should be safe enough to handle. If and thats a big if, thats what it was from.

I would just melt it down and purify it again. I have a hard time letting lead go. A couple handle fulls of sawdust and let it simmer for about 10 to 15 minutes

Sent from my SM-G950U using Tapatalk

It's the calcium (Ca) that's alloyed with the lead in newer batteries to harden the plates that's an issue combined with the arsenic (As) and antimony (Sb) present in wheel weights.
Arsenic and antimony are in the same group in the periodic table, antimony being directly below arsenic, so their chemistry is similar.

First they react with calcium to form a compound, which then reacts with water, present in the ambinet atmosphere, to form extremely toxic aresine (AsH3) and stibine (SbH3).

2 As + 3 Ca -> As2Ca3

Then, upon contact with water the calcium is oxidized and the the arsenic or antimony reduced;

As2Ca3 +3 H20 -> 3 CaO + 2 AsH3


Now, here's the thing. As you can see the reaction requires a significant amount of water stoichiometrically in order to proceed. While it will certainly occur at the surface of the pot, it will not occur in the bulk of the alloy, and in my opinion cannot be responsible for voids forming throughout a block of the metal.

Further, both of these gases readily oxidize with contact to atmospheric oxygen to the volatile metal oxide (something like 2 AsH3 + 3 O2 -> As2O3 + 3 H2O) and the oxides have an intense garlic like smell. I would think if you produced enough to intensely bubble the alloy like that, you'd notice something, if not only the symptoms of poisoning very shortly after. I doubt that is what is responsible.

Now the following is complete conjecture. Maybe if anything from a battery was causing the bubbling it would be the sulfuric acid? Sulfuric acid has a boiling point of about 640 degrees fahrenheit, just above the melting point of lead. Above that it decomposes to give products that are a gas. I know sulfur is soluble in lead to an extent, but I don't know that sulfuric acid is. If it was, and it was present in the alloy initially, it's thermal decomposition is a good a theory as I can come up with as to what would case bubbles to form like that. But again, you would have almost certainly smelled something, rotten eggs this case.

But this is just spit balling, and not particularly informed spit balling at that.


Anyways, go send a sample off to get analyzed with XRF and report back. Like I said i'm rather curious myself.

[Traffer]

Yes it is a curious and intriguing thing indeed. Since the original post I have searched pretty well on the good ol web and found nada. Of course I am not a chemist so just forming a decent search question may be beyond my pay grade here. But I certainly would like to find out the answer to this one. As others have suggested, send BNE a private message and get it scanned or you will keep us in suspense.