Seperating Lead

[Sliver Shooter]

This may be a really dumb question but, can one seperate lead out of a mix of metals? Using different degrees of temp, will like tin melt away from the lead or antimony mely away at a certain temp? Sorry if that is stupid. I have some ingetts that I made from WW and they are almost crystal like and brittle. Darn hard. They melt at less than 700 degrees so I don't think I have any zink in them. I had some fall on the cement floor when dumping them out of the mold, and they broke like they were crumbly. I that makes any sence. :???:

[sqlbullet]

Well, the answer to you question is both yes and no.

Lead/tin/antimony alloys can be both mixtures and solutions, depending on the temperatures and ratios of the constituent metals. A ternary phase diagram conveys this information.

An example we are generally all familiar with is sugar and water. If you add a little sugar to a glass of water at room temperature, it will dissolve, and you will have a solution of sugar water. Keep adding sugar and eventually the water become saturated with sugar and no more will dissolve. You know have a mixuture of sugar and sugar water solution.

Heat will allow more sugar to dissolve into the solution, raising the percentage of sugar in the solution. Some of that sugar will stay in solution even after it cools, giving us syrup. However, if you add too much sugar, then when the solution cools, some of the sugar will precipitate out forming sugar crystals.

Now, in lead alloys it gets really interesting. For instance, the amount of tin and antimony that will dissolve in lead vary with temperature, just like sugar and water. But, that amount varies even below the solidus line of the overall alloy. More tin/antimony will stay dissolved at 250° than at 75°. Further, the lead/tin/antimony eutectic solutions will melt at lower temperature than the lead/tin/antimony mixture that is together in the pot.

Your crumbly ingots are expected with WW alloy. As a non-eutectic alloy it's solidus and liquidus temps are different. It is no longer a solid after about 470° but is not fully liquid until about 525° or so. The ingots that crumbled were probably within 100° of the solidus line, and were kinda like mud.

[bangerjim]

You cannot "separate tin or ant from lead.....at least with the equipment you have available (a gas/electric pot)!

In a lab.......yes......but the cost???????.....prohibitive.

sql's explanation above is very good.

I have a Eutectic alloy of about 55% Bi 22% Pb, 13% Sn and balance Sb. And it melts at 158F!!!!!!! And has a 22+ Bhn. Eutectic metals are amazing. But no way can they be separated in a home environment.

Now, if you have zinc in there, you can remove it (and all the tin and ant!) by using either sulfur or copper sulfate as a flux. Not a pleasant job, but you are left with almost pure Pb that you can add known quantities of what you want back in. The other metals are NOT easily recoverable from the oxides left. Search on here for the thread about the process. I have used it just to test it out.

As far as crumbly........your lead is too hot. Let the ingots cool longer. They are, even though they look solid, in that slushy area as he mentioned above. Set your ingot molds on wet towels to cool down faster!

Good luck!

bangerjim

[Spawn-Inc]

As far as crumbly........your lead is too hot. Let the ingots cool longer. They are, even though they look solid, in that slushy area as he mentioned above. Set your ingot molds on wet towels to cool down faster!

Good luck!

bangerjim

second that, but don't dump the ingots like i used to do into water as most of them sucked water into them as they cooled. the result i get is when i am heating them back up in my production pot i get alot of bubbles from the steam. i have to hold them with channel locks and slowly dip/melt them.

[Springfield]

Let them cool longer, ingots can stay hot enough to break for over 20 minutes, depending on size and shape.That's why I like to have enough into moulds to do at least 50 lbs at a time.

[w5pv]

As long as you can take something like a pair of channel locks or something similar and bump them i the mold and they indent they need to cool further.After a little practice you will be able the feel the process.

[Defcon-One]

Read all that if you want to but the simple answer is NO WAY! As one of them said it is all "dissolve in lead"!

The ingot are normal, just wait longer.

[btroj]

An alloy is a solution of metals that can't be separated by physical means, it can be separated by chemical means. That is how foundries do it, they add fluxes of various types, alter the atmosphere, and add various gasses via bubbling it they the molten metal.

Gravity separation just doesn't happen.

[dikman]

Bangerjim, I just want to see if I've got this straight - you're saying that if I flux range scrap with copper sulphate (presumably fairly heavy fluxing) then I will eventually be left with reasonably pure lead? This seems at odds with Popper's post elsewhere, where he says that you'll end up with a harder alloy with some copper in it. I'm confused.

I'd appreciate it if you could clarify this for me, please, as I can't see what I'm missing here.:veryconfu.

[Defcon-One]

dikman: It'll never work. That is what you are missing. Also, It is not worth the effort or expense. My advice, make sinkers, then find some good lead.

[btroj]

It is very difficult to judge things from ingots. Hot Ingot moulds cool slow enough to give very crystalline ingots. This tells very little about the composition of the Ingot.

Don't mess with copper sulfate or anything else. Try casting with your lead and that will tell you all you need to know. It may want a bit of tin but I bet it casts fine.

[bangerjim]

[QUOTE=dikman;2551049]Bangerjim, I just want to see if I've got this straight - you're saying that if I flux range scrap with copper sulphate (presumably fairly heavy fluxing) then I will eventually be left with reasonably pure lead? This seems at odds with Popper's post elsewhere, where he says that you'll end up with a harder alloy with some copper in it. I'm confused. [QUOTE]



1st......You should NOT have Zn in range scrap!!!!!! The chemical process is suggested for use on KNOWN contaminated WW melts only.

Well........from all that I have read and the samples I have intentionally contaminated with Zn (at 875+ F) and ran this process on, it seems it will remove Zn. Adding Cu???????? Who knows! I do not have an XRay gun for analysis. The balanced chemical reactions lists by others indicate such.

I just took the little bit I did decontaminate (~4#) and used it in the pot with pure. Did not measure the hardness but the acid test did not react at all....even a little bit of color will happen....as it will with a bit-o-zink.


What you may be missing is the suggestion by others.......make sinkers out of it! Unless you have a WHOLE BUNCH of accidentally contaminated lead, it is not worth the time and effort to try to extract the Zn out.

It is a chemically-possible reaction....(I tested it just for the heck of it), but if you run your melt at 600-650F, Zn will float to the top and you NEVER melt it by accident. Of course....first of all....."sort B4 smelt". Zinkers are very easy to ID when you are sorting.

Fluxing with Sulfur or Copper sulfate is a last-ditch, OMG, "what the heck did I just do" process.

Good luck!

bangerjim

[dikman]

Now, if you have zinc in there, you can remove it (and all the tin and ant!) by using either sulfur or copper sulfate as a flux.
bangerjim

Sorry for the confusion, I wasn't actually concerned with the zinc bit (I realise range scrap is unlikely to have zinc in it), rather the reference to removing the tin and antimony.

[bhn22]

You can't remove them. If your alloy is too hard, remelt it and cut it with pure lead. As mentioned above, the speed with which your alloy is cooled affects the alloys crystalline structure. All in all, after rereading your post, it sounds like you simply tried to dump the ingots from the mold, and they weren't yet hard enough for that, so they broke. Your description exactly matches this scenario. I think your alloy is probably fine, it just takes progressively longer for ingots to fully freeze because the ingot molds get really hot, and actually help keep the metal inside molten longer. That's one reason most of us have so many ingot molds, I think I have at least ten myself. Just let the molds sit a while longer, preferably on unfinished concrete, or something that will act as a heat sink.

[btroj]

:goodpost:

I have many ingots that look like that, I can guarantee you they don't have zinc in them. Hot mould, dumped too soon, give crystalline, fractured ingots.

[Sliver Shooter]

WOW you guys. Thank you. I just had the most enjoyable read on here. You guys know your stuff. I have caste for many years but really have never known anything about what makes up the casting material. I have probably 200lb or more of various lead. WW are the main source and I have melted them down and poured them into a caste iron muffin tray to make ingots. I had some crystaline on me(I guess that's what it did) and the boolits are smoky silver in color compared to other batches I have caste. What I should do is find me a big kettel and melt all I can into one mix and see what I end up with. That way it will be all a consistant mix.

[bangerjim]

This works for me:

When I melt new batches of "soup", I keep them segregated and mark them with bhn and color the ends with transparent wood lacquer for ID later. Then, I can grab a bit of this and a bit of that to make my casting lead batch.

Every batch could/will be different. But today, we have learned thru much testing by many that hardness is not a critical as once touted in the "olde days". Back then, EVERY piece of load data was either lino or Lyman #2. (still is in the "books"!) Now, most of us cast a lot softer with great results. (alloys will shrink differently, so you have to be cognoscente of that weight/size shift that can occur).

Many of us are now powder coating and not using grease lubes any more. PC'ing allows wideer variations in hardness with absolutely ZERO leading and smoke from your fire arms. If you are not familiar with the process, check the stickies on electrostatic gun PC coating. Fun & easy. And much cheaper than buying a lubra-matic.

Good shooting!

bangerjim

[dikman]

You can't remove them.

That was my understanding too, based on what I've read here, but then I read bangerjim's statement, hence my confusion. He knows far more about this stuff than I ever will. (I have no problems with crystallized ingots, etc - the cooling processes for lead are simple enough to understand).