A possible way to remove zinc from molten lead

[sciguy]

While researching the true meaning of 50:50 solder, I came upon some information describing how to make different solder mixtures. Part of the article mentioned how a very small amount of zinc will "poison" the solder and goes on to explain how to remove the zinc by fluxing with sulfur.

Perhaps this has been brought up before but the information was new to me. There seem to be a good number of posters who have accidentally "poisoned" their wheel weight melts and if this helps clean up their alloy then I've done my good deed for the day.

Most relevant passages:

"From this it is clear that in making solder great care must be taken to exclude zinc from the pot. Zinc, lead, and tin do not alloy well, lead will unite with only 1.6 per cent of zinc, and above that proportion the metals are only mixed when melted, and on cooling partially separate.

Sufficient lead having been melted in the pot, about ½ pound of lump sulphur, broken into pieces about the size of hickory nuts, is added, and the whole well stirred with a ladle, the sulphur unites with zinc and other impurities. The resultant sulphides are skimmed off in the form of a cake, more sulphur being added so long as sulphides continue to form. The bowl of the ladle, in the intervals of stirring, should be laid on the fire, to burn off any adherent sulphur. When sulphide ceases to be formed, a handful of resin is thrown into the pot, and the lead stirred. When the resin has burned, the lead is again skimmed, and a piece of tallow about the size of a hen's egg is put into the pot, the lead being again stirred and skimmed. In stirring the lead it is lifted up and poured back by the ladleful, a larger amount of lead being thus exposed to the action of the cleaning material."

&
"Zinc is the greatest trouble to the solder pot. Great care has to be taken to exclude it, or to get it out. It may get into the solder from a piece of zinc, having been put into the pot by mistake for lead, but more commonly brass, which is an alloy of copper and zinc, is the source of the zinc that poisons the pot, into which brass filings find their way whilst brass is being prepared for tinning. If the filing is done at the same bench as the wiping, splashes of metal may fall on the filings, which will adhere, and thus get into the pot. Solder that is poisoned by arsenic or antimony is beyond the plumber's skill to clean, but zinc can be extracted by stirring in powdered sulphur when the solder is in a semi-molten condition, and then melting the whole, when the combined sulphur and zinc will rise to the surface, and can be taken off in the form of a cake, the solder being left in good condition for use."


Link to the whole page : http://chestofbooks.com/home-improvement/construction/plumbing/Practical-Plumbing/How-To-Make-Solder.html

Hope this helps some of you kind folks,

Hugh

[big boar]

Thank you for that info, I've been concerned about the chances of getting the odd bit of Zinc in my melt. Getting harder and harder to get WW up hear.

[geargnasher]

Chemists here correct me, but lead and tin also form sulfates, but maybe not just by being mixed with sulfur. IIRC from college inorganic that sulfur transfers from one metal to another, changing one into the SO4 and leaving the other as elemental metal, I remember playing with copper sulfate and tin but never lead sulfate in the lab.

I really shouldn't care how this works if it works!

Someone have a contaminated alloy they'd like to try this on?

Gear

[Ron.D]

Sciguy. Great piece of info. I've got about 3-400lbs. of WW that got a little too hot when I smelted it and I believe has some zinc in it. I can use it for large boolits if I heat it slowly and skim well, but I'd love to fix the whole batch. This solution may or may not be the holy grail, but it sounds well worth some experimentation. Thanks for the info. What a great site this is. Ron.D

[arcticbreeze]

I have about 80 lbs with I believe some zinc. I was going to just give it away to someone willing to try it but I will give this a try and report back.

[sciguy]

I have about 80 lbs with I believe some zinc. I was going to just give it away to someone willing to try it but I will give this a try and report back.

I'm hoping that it will. Finding the solder making site was pure accident but the method of zinc removal seems totally appropriate to our purposes.

They use sulfur as an organic pesticide. It looks pretty cheap if bought in the 90% form mixed with bentonite clay. I'm not sure if the bentonite would hurt at all.

Hugh

[rob45]

They use sulfur as an organic pesticide. It looks pretty cheap if bought in the 90% form mixed with bentonite clay. I'm not sure if the bentonite would hurt at all.

Hugh

I don't see where the bentonite clay would cause any problem, considering the fact that I have used kitty litter as a top insulator for years.

[geargnasher]

I don't see where the bentonite clay would cause any problem, considering the fact that I have used kitty litter as a top insulator for years.

+1 Rob.

Gear

[luke777]

Fantastic piece of information to have in the back pocket SCIGUY.

I will be printing this one off and storing it in preparation for potential future battles. Fingers crossed I will never have to use it but.... You know how the old saying goes!!

Luke

[mcooper]

Will the sulfur take out tin or antimony in an appreciable amount?

[sciguy]

Will the sulfur take out tin or antimony in an appreciable amount?

I really don't know about the tin but the document implys that antimony will not be removed by the process. Even if all of the tin was removed from wheel weights, adding 2% more tin after "cleaning" would be pretty inexpenive compared to losing a huge batch of wheel weights that you spent so much time, effort, donuts, pizza, sweet talking to collect.

Solder that is poisoned by arsenic or antimony is beyond the plumber's skill to clean, but zinc can be extracted by stirring in powdered sulphur when the solder is in a semi-molten condition, and then melting the whole, when the combined sulphur and zinc will rise to the surface, and can be taken off in the form of a cake, the solder being left in good condition for use."

If this process does prove to be functional, a sticky should be created for test data, procedurural explanations, pictures.................


Hugh

[dominicfortune00]

Arsenic and antimony can be good things, depending on what you want your end results to be.

[sciguy]

Arsenic and antimony can be good things, depending on what you want your end results to be.

As is the small amount of tin in wheel weights.

Hugh

[shotman]

I dont think you would want to do that in the house. LOL but it will get rid of the bugs.If you use a therometer you can get most all the zinc out . the oil dry will get about 98% of the rest if you keep temp at near 700 Zinc will float at that temp keep stiring and dont use flux and most will get out

[mcooper]

Arsenic and antimony can be good things, depending on what you want your end results to be.


I want the tin and arsenic...that's why I ask. If I have to add it later, no biggy; I just want to know if I need to.

[SciFiJim]

Like antimony, sulfer is also one of the elements that can be added to lead to allow it to be hardened by heat treating. There was a discussion some months back about what we would have to do if antimony becomes hard to find after WWs disappear. Sulfer can be added to pure lead by holding it submerged in molten lead. It doesn't take much.

[oscarflytyer]

OK - where do you find the sulfur!?! And has anyone tried this yet? Thanx in advance.

[sciguy]

OK - where do you find the sulfur!?! And has anyone tried this yet? Thanx in advance.

The process does appear to work. Follow the link below.

http://castboolits.gunloads.com/showthread.php?t=63082

Gardening stores sell 90% sulfur pretty inexpensively.

Be carefull with the fumes, and possible moisture that may be in the sulfur.

Hope to see more experiments soon.

Hugh

[runfiverun]

sulphur will also help with the graining of the alloy,leading to a denser alloy.

[Ohio Rusty]

Aren't road flares mostly sulphur ??? I'm sure you can still get sluphir, or flowers of sulphur.
Ohio Rusty ><>

[Ricochet]

Flowers of sulfur started getting hard to find back in the early '70s, when I was still experimenting with "applied chemistry." So did saltpeter.

[Lunk]

Flowers of sulfur started getting hard to find back in the early '70s, when I was still experimenting with "applied chemistry." So did saltpeter.

You can buy food grade saltpeter on the 'net now. They limit you to like 1lb a month or so so "applied chemistry" may not be all that useful.[smilie=1:
I imagine that the same places sell sulfur as well but have not looked as of yet.

[First Big Foot]

I was just wondering the same thing, "Where do you get sulpher?"

Then somebody suggested a garden shop, and I remembered my gardening buddy using sulpher for the garden.
Gonna ask him.

[Triggerhappy]

I can get it here at the drug store, right next to the saltpeter. It's sold in 1# white plastic jars. Couple of bucks.

TH

[jsizemore]

Isn't powder to keep snakes away made of sulphur?

I've gotten rid of all the zinc and steel wheel weights (some local tire shops recycle them and I get their stick-ons). If I had some I could reverse engineer a batch in straght wheel weights and see if the zinc I got out was the same as what I put in. I'm probly not the only one to think this.

[SciFiJim]

I live in an area that has lots of vineyards. Sulfur is delivered to the vineyard by dump truck and dumped beside the road by the ton.

I think that it would be a "last resort" option. Its easier to keep zinc out than to get it out.

[jsizemore]

I think that it would be a "last resort" option. Its easier to keep zinc out than to get it out.

I sort my WW, but stuff happens.

[Ricochet]

See that thread in the cast boolits section about 50/50 lead/zinc boolits. Sounds like arsenic may help the zinc blend in?

[linus9]

i have some lead that i suspect has some zinc in it. how can you tell? how does the melted lead/ zinc behave or look?

thanks, mike.

[rob45]

i have some lead that i suspect has some zinc in it. How can you tell? How does the melted lead/ zinc behave or look?

Thanks, mike.

oatmeal

[docone31]

Grey oatmeal.

[45-70bpcr]

At the risk of looking stupid, aren't matches and as someone else said road flares made mostly from sulpher? What keeps these big lumps of sulpher from accidentally igniting into a big fireball? I understand flash points and these temps may be well under what it would take to make sulpher ignite but what if you accidently stir the pot with a spoon that had some wax flux left on it or something?

[sciguy]

At the risk of looking stupid, aren't matches and as someone else said road flares made mostly from sulpher? What keeps these big lumps of sulpher from accidentally igniting into a big fireball? I understand flash points and these temps may be well under what it would take to make sulpher ignite but what if you accidently stir the pot with a spoon that had some wax flux left on it or something?


I believe that matches and road flares have an oxygen providing compound as one of their ingredients. You would be amazed how quickly a huge number of materials would combust when mixed with a good provider of oxygen.

Hugh

[Bulltipper]

Well I've got a bunch of contaminated stuff to try this on. Shore is pretty all gold and blue...

[HORNET]

The colors don't necessarily indicate contaminated alloy. See: http://castboolits.gunloads.com/showthread.php?t=63550 . If it looks like lumpy gray/silver oatmeal that doesn't want to dissolve back in at the lower end of casting temperature, you might have a problem. If it dissolves back in, it might have been your antimony & tin.

[magmoose]

I may have a couple of zinc weights in about 100 pounds of wtts. How much zinc is the SWAN SONG for a batch of wtts???

moose

[sagacious]

Well I've got a bunch of contaminated stuff to try this on. Shore is pretty all gold and blue...
Blue and gold colors are not signs of zinc contamination.

Test pour your alloy, and if it pours well, all is OK. Good luck.

[sagacious]

I may have a couple of zinc weights in about 100 pounds of wtts. How much zinc is the SWAN SONG for a batch of wtts???

moose
Do some test pours and see how the bullets come out. If it pours fine, then no problem. It's results we're after, and if you get good results, you're OK as-is! Good luck.

[Bartster]

I had a batch of molten lead, wheel wts only, and as it was close to final skimming and casting into my pigs, it turn very dark, black and powdery, the more I skimmed it the worse it got. Is that a result of Zinc contamination ? Thanks.

[sagacious]

I had a batch of molten lead, wheel wts only, and as it was close to final skimming and casting into my pigs, it turn very dark, black and powdery, the more I skimmed it the worse it got. Is that a result of Zinc contamination ? Thanks.
Sounds like waaay too hot. When overheated, ww alloy will form a dross that turns dark and powdery. Reduce the heat a bit-- more heat is not always better. Good luck.

[comershooter]

I was told to melt lead at 650 since zinc melts at 787 that way you just skim
them off.

[badbob454]

I like to seperate all my wheel weights buy hand feel, and sound . the zinc has a hi pitch sound almost as high as iron .. steel will stick to a magnet or has the symbol fe on it .. zinc has zn on it .. and stick on ww lead is @ 99% lead ,usually good for black powder or slow bullets . they now have zinc and steel stick ons so be carefull .. lead is heavy and has a dead ring or dull sound ,,, some use pliars to test for zinc as zinc will not deform as easily as lead it is very hard... this may help to allieviate zinc contaminations in the pot.. hope this helps

[rattletrap1970]

If you melt below the melting point of Zinc you will not have a problem. Really.. It's that simple.

I kinda pimped out my Lee Production Pot.

1. I have a digital 1/16 Din Omega Thermometer with a thermocouple in the pot.
2. The Thermometer is powered by a 24v Din mounted power supply.
3. The production pot is kept on it's highest setting and is "plugged in" to a relay that is kicked by the thermometer.
4. The relay is connected to the wall.
This allows me to very accurately control the melt.

[Pb&j]

If you melt below the melting point of Zinc you will not have a problem. Really.. It's that simple.


This statement just made my day. The last smelt of the afternoon I found silvery oatmeal floating but luckily I've been keeping tabs on the temperature. Was just under 650 so I figure with the above being said, I'm still good to go. Newbie with ww. I know what I'll be looking harder for.

[161]

I went to the drug store today, the pharmacist (SP?). Was a classmate of mine so I didn't feel like an idiot when I asked for surfer. He gave me a 4 oz bottle of flowers of sulfur that was about to expire. There is no content label, just says sulfur sublimed powder usp. Will this work in a small test patch in my 20# pot?
Thanks
Warren

[btroj]

Chemists here correct me, but lead and tin also form sulfates, but maybe not just by being mixed with sulfur. IIRC from college inorganic that sulfur transfers from one metal to another, changing one into the SO4 and leaving the other as elemental metal, I remember playing with copper sulfate and tin but never lead sulfate in the lab.

I really shouldn't care how this works if it works!

Someone have a contaminated alloy they'd like to try this on?

Gear

The article speaks of forming sulfides, not sulfates. I think it is the ease with which the Zn will combine wight he S that makes the sulfide formation possible. This sulfide would not be soluble I. The melt so it can be skimmed off.
I am sure some lead and tin are lost also but sometimes you need to make a sacrifice to save the larger share of your melt.

[blackbike]

A possible way to remove zink from molten lead' easy skim it off berore the melt reaches 675 degrees. If you screw that simple task up, you`r on you`r own

[GunStuff]

From a chemistry point of view the zinc is a much more reactive metal than are the others mentioned. The electromotive series is a relative scale that lists elements from most reactive to least reactive. Here is the list starting with zinc: zinc>chromium>iron>cadmium>cobalt>nickel>tin>Lead>hydrogen>antimony=arsenic=bismuth>copper. While sulphur may react with a small amount of the tin and lead, it will largely react with the much more reactive zinc metal.

The suggestion to separate the zinc weights from the lead weights should be done first. Then separate out any zinc that slipped through by adjusting the temperature of the pot to melt the lead but not the zinc which will float on top. Finally, eliminate the residual zinc with the sulphur treatment. That should leave you with an alloy/lead containing very little zinc.

The melting points of pure metals: lead 327.3ºC , zinc 419.5ºC, steel ~1375ºC The specific gravity of pure metals (how heavy they are compared to the same volume of water) lead 11.3, zinc 7.1, steel ~7.7 . That's near room temperature. At a higher temperature the numbers change a little but both solid zinc and steel (the cllps) will still float on liquid lead.

No one has suggested distilling the zinc off. It could be done as zinc boils at 907ºC while lead boils at 1750ºC. OK, that's a stupid suggestion but it's fun to throw it out there for the back yard distillers to contemplate.

[nwilson1024]

i have been looking over this thread the past few days and I had an idea that popped into me head today. This is a little excessive and time consuming but I think it just might work. I mention this to try and spark ideas from others.
So as stated HCL will react with the zinc and not this lead. This we know. The problem becomes that we have ingots and dunking them into CHL will only treat the surface area of the slabs. My thought was to make as much surface area as possible then treat the mix in HCL.
If one were to melt the mix to liquid form and take a ladles worth at a time and CAREFULLY toss it onto a cooler surface (like a piece of sheet medal) the mix would harden almost instantly. This would create much more surface area for treatment in HCL and much less area that would be shielded from the HCL. You would just gather all of these thin pieces of mix and drop them into HCL and let the zinc bubble to hydrogen leaving only the lead and other alloys behind.
I realize this would be time consuming, and might not even work that well, but like I said just trying to spark some thought.

[jfl1950]

What if you just used a lower temp as zinc melts higher then lead does?

[gidgaf]

I would like to remind folk, as is was mentioned, that sulfur is commonly used as an insecticide. As simple as flowers of sulfur, in a box, with a wick. You will have bugs falling from the sky- or at least the ceiling. Make sure you are not downwind, and have lots of ventilation. Lots and lots.

[Markbo]

What if you just used a lower temp as zinc melts higher then lead does?

That is a good plan. Now for those of us that have melted ingots that may (read definitely do) have zinc in the mix, this thread is for them. I didn't want to have to try sulphur (the neighbors will NOT be happy) but apparently this is the best way to clean up what already has a little zinc problem. Had I known it was this big a problem I would have been more careful separating the zinc wheelweights in the first place. Thank goodness I have seen this so that I will take that time for the rest of the buckets I have!

[GunStuff]

This has been a very informative thread and I make sure to separate the zinc and iron ww before I melt them. In post #1 there was a statement that no one has picked up on that I would like to explore: " Zinc, lead, and tin do not alloy well, lead will unite with only 1.6 per cent of zinc, and above that proportion the metals are only mixed when melted, and on cooling partially separate."

So only 1.6 % of the zinc will incorporate with the lead and the excess should also float on top of the lead which could be skimmed off. It's like oil floating on water except here both layers are silvery which makes seeing the zinc layer problematic. However if you think you have zinc just skim off some of the top layer.

The remaining 1.6% could be diluted to 0.8% by melting in an equivalent of pure lead. Now you have twice as much contaminated lead, but what are the negatives of this alloy for casting and shooting? I don't know. I would certainly do some skimming before treating the remaining 1.6% with sulfur.

[williamwaco]

You can get sulphur at any garden store. It is very inexpensive.
Two or three dollars for five pounds.
You only need a few tablespoons for a 20 pound pot.



I have use this method.

It works:

I CANNOT ADEQUATELY DESCRIBE THE FUMES.

Do this outside. Away from the house.
If there is no wind, have a large fan running.
Be sure you stand up wind.

BE CAREFUL DO NOT LET THE FUMES GET IN YOUR EYES, NOSE OR MOUTH.

BE CAREFUL.


.

[Markbo]

This is a repeat of a post in another thread: I think the problem is using a Propane turkey fryer, the temp gets above 600° whether I plan on it or not. Think of a 2/3 propane tank - my smelting pot - almost full of wheel weights. By the time the liquid is visible or enough that it floats what's on top of it, that temp in the bottom (and yes I do use a top) has exceeded zinc melting temperature. I have no doubt about that. Leaving some lead in the bottom & slowly adding weights will reduce the possibility of contamination as will pre-sorting the weights.

Having done the sulfur stuff this weekend I'd prefer to not have to do that any more. It was not pleasant and I had to wait for the time and the right weather - clear and quite breezy - to do it. Sooo... I also spent time this weekend sorting through all my wheel weights and got roughly 50/50 lead and other - 3 x 5 gal buckets of each. I have segregated the lead and will sell off the other. Was sorting all the weights a pain? Sure was. But not as bad as the constant wondering 'if' my melt is contaminated and why I can't get bullets to fill out nicely. Now that I know I have cleaned out these ingots I can also know that my stock is good and hopefully not have the casting issues I had in the past. I will post a thread about my findings in due time.

Like someone said in another thread, this ain't rocket science. But it sure does make it easier when you know a lot more about it!

[Clay M]

It will smell like a giant fart. Your wife will love it!!

[HamGunner]

Keep a little of the sulfur around for chigger and seed tick protection. If sprinkled in one's socks and on the inside of pants legs, it works wonders. Not the best smelling, especially when combined with a bit of sweat, but it does work better than most any other repellent for those times when one must wade right on in there regardless of the creepy crawlers.

[kingemandigger]

You can get 99.95 sulfur powder in 10 lb. bags from fertilizer stores online. It is also not very expensive, I forget exactly how much it costs though. I use it as an ingredient in home made black powder

[Bogone]

You can get it by the pound from amazon 15.50 for 5 lbs. http://www.amazon.com/5-lb-Sulfur-powder-Brimstone/dp/B003OJDEEI/ref=sr_1_4?ie=UTF8&qid=1387328035&sr=8-4&keywords=sulfur.

[Brucifer]

I have 50lb of melted cww. I used a LP burner and am sure the zinc is in the lead. I just blended in 1/2 lb of sulfur in 6 to 8 attempts. Have lost maybe half of the amount in the pot. Will the sulfur stop? How do I know when all the zinc is removed?

[amosfella]

i have been looking over this thread the past few days and I had an idea that popped into me head today. This is a little excessive and time consuming but I think it just might work. I mention this to try and spark ideas from others.
So as stated HCL will react with the zinc and not this lead. This we know. The problem becomes that we have ingots and dunking them into CHL will only treat the surface area of the slabs. My thought was to make as much surface area as possible then treat the mix in HCL.
If one were to melt the mix to liquid form and take a ladles worth at a time and CAREFULLY toss it onto a cooler surface (like a piece of sheet medal) the mix would harden almost instantly. This would create much more surface area for treatment in HCL and much less area that would be shielded from the HCL. You would just gather all of these thin pieces of mix and drop them into HCL and let the zinc bubble to hydrogen leaving only the lead and other alloys behind.
I realize this would be time consuming, and might not even work that well, but like I said just trying to spark some thought.

The process is done by slowly and in a very thin stream, pouring the molten metal into a pail filled with ice cubes. HCl will dissolve the zinc, but it will make a very big mess of the lead forming lead choloride. That's a big mess to undo.

[amosfella]

From a chemistry point of view the zinc is a much more reactive metal than are the others mentioned. The electromotive series is a relative scale that lists elements from most reactive to least reactive. Here is the list starting with zinc: zinc>chromium>iron>cadmium>cobalt>nickel>tin>Lead>hydrogen>antimony=arsenic=bismuth>copper. While sulphur may react with a small amount of the tin and lead, it will largely react with the much more reactive zinc metal.

The suggestion to separate the zinc weights from the lead weights should be done first. Then separate out any zinc that slipped through by adjusting the temperature of the pot to melt the lead but not the zinc which will float on top. Finally, eliminate the residual zinc with the sulphur treatment. That should leave you with an alloy/lead containing very little zinc.

The melting points of pure metals: lead 327.3ºC , zinc 419.5ºC, steel ~1375ºC The specific gravity of pure metals (how heavy they are compared to the same volume of water) lead 11.3, zinc 7.1, steel ~7.7 . That's near room temperature. At a higher temperature the numbers change a little but both solid zinc and steel (the cllps) will still float on liquid lead.

No one has suggested distilling the zinc off. It could be done as zinc boils at 907ºC while lead boils at 1750ºC. OK, that's a stupid suggestion but it's fun to throw it out there for the back yard distillers to contemplate.

Something similar is used in refining. Zinc is added in the refining process. Gold and silver are very attracted to lead, much more so than the Iron sand in which they are usually found. Zinc s added in the molten state after the iron is removed and melted in, as zinc is around 3000 times more attracted to gold and silver than to lead. The zinc then forms a dross on the top as the pot cools, and is skimmed off. Then the zinc is then boiled from the silver and the gold and recovered for reuse... Charcoal or coke is used to rid the lead of the zinc.

[DrBill33]

PLEASE111 WATCH THE FUMES. They can be quite toxic. I stand with my fan behind me and blowing fumes away.

Lump S is hard to find around here, so I went to my Druggist (a shooter) and bought some "flower of sulpher

Good Luck!

[kryogen]

if you guys care I have found 5 pound bags of powdered sulphur for like 10$ in the hunting section at canadian tire. For deer I think? No clue why. Maybe you could find some in hunting stores.

[kryogen]

This is a repeat of a post in another thread: I think the problem is using a Propane turkey fryer, the temp gets above 600° whether I plan on it or not. Think of a 2/3 propane tank - my smelting pot - almost full of wheel weights. By the time the liquid is visible or enough that it floats what's on top of it, that temp in the bottom (and yes I do use a top) has exceeded zinc melting temperature.

I have had one batch fail doing that. I filled the pan, cooked, everything melted in an ugly slush. I did the cooling and heating skim, lots of fluxing, removed probably 95%....

What I did before, and now do, is start with just an inch layer in the bottom. let melt, skim. add an inch of weights, let melt, skim.
I don't separate weights now. I just add a bit and skim, keeping the mix just above lead melting temp. zn doesnt melt. just skim off with clips.

Works 100% easier for me.

Separating is a hassle, takes hours and hours, and I STILL got some zn that wasnt identified in the mix. I just skimmed off.
faster imo is just to dump more into the mix, re-heat to liquid, skim off, ... keep going.

[biffj]

I believe that matches and road flares have an oxygen providing compound as one of their ingredients. You would be amazed how quickly a huge number of materials would combust when mixed with a good provider of oxygen.

Hugh

Not sure if road flares have any sulfur at all but they do have a lot of Strontium nitrate and wood meal. The wood meal provides a fuel and the Strontium nitrate is an oxidizer and colorant. It makes the flame red. I do believe there is pvc included too as it makes the color brighter and more red.

Frank

[mold maker]

For all those that proclaim the simplicity of Just Keeping The Temp Below the melting point of zinc, it aint that easy.
If we only used a heat source that produced less than 725 degrees, we would take forever to melt even pure lead. The flame licking the pot is measured in thousands. The heat transferred through the pot is also measured in numbers way over the zinc melting temp. If just a single zinc weight was missed and happened to be against the pot, under the weight of all the lead above it, guess what happens to it. It melts. It is melted before even 5% of the lead.
Getting the zinc out of a melt is iffy at the very best. Keeping it out of the pot to begin with is the answer.
It takes less time to pinch everything, than to look for the symbols or fishing out (hopefully the only) floating Zn weight. It makes no sense to collect, half look, and melt contaminated alloy. Either do it right or pay someone else, and hope they did it right.

[Southron]

I went to the Sanders Lead Company in Troy, Alabama a few years ago. They have an industrial tower/bui9lding that looks like a cracking tower found in oil refineries. One of the Engineers told me that they bring in scrap lead and then heat it up to 2300 Degrees Fahrenheit and separate ALL the various metals from the lead.

They sell their pure lead in 60 pound ingots and will actually give you a computer print out of all the metals in it. Their "Pure" lead is around 99.96% pure if I recall correctly.

[OldBearHair]

I had an occasion once to try to separate Sulphur from Bentonite Clay and use the Sulphur in making Black Powder. Filled a gallon jug (big lid) 1/2 full of water and added the Feed Store bought Sulphur until the mixture was fairly thickened. Then you shake the jar for a while then let it settle. The Sulphur goes to the bottom. Then dip out the remaining water and clay down to the Sulphur. You will probably take out a little mix of both products. Pour out the Sulphur in a large pan that is tilted a little. The water will drain and can be picked up with paper towels. Let it completely dry and you have usable Sulphur.

[AllanD]

I am constantly mystified by the fact that most casters are worried about Zinc, but unaware that during commercial refining of lead that it is intentionally mixed with molten zinc...This is because in mining and refining lead, the lead is essentially pure profit.
How you ask? the SILVER (and there is typically a small amount of gold found as well) that is always mixed into native lead pays for everything!!!

Read up on the Parkes Process (https://en.wikipedia.org/wiki/Parkes_process) for an understanding of the chemistry involved...

I recall there was another process for separating zinc from lead or tin using copper sulfate but I would be hesitant to use the commonly available Copper sulfate... as those pretty blue crystals are not something you want to be adding to a pot of molten metal without expecting a visit from the tinsel fairy...

Those pretty blue crystals are more technically known as "Copper sulfate Pentahydrate" (make thyself familiar with the
term "water of crystallization")

OldBearHair, Sulfur is not chemically important in black powder mixtures... it's function is more as an "Emulsifier" to aid even granulation. Black Powder is essentially a fuel/oxidizer mixture, the charcoal is the fuel and he Nitrate is the oxidizer...

[popper]

Just don't push those pretty blue crystals under the lead until they turn white - the H2O is gone then and no tinsel fairy. Safely dispose of the brownish powder dross - wear a painters mask when handling the dross. It is a fine powder that is not good for you. Sulfur burns very well.

[Nose Dive]

Well.... has been a long while since i 'revisited' our sticky collection... a long time....

Removing zinc is an issue for good mold fill out. The best way, is to keep it out of your smelt pot. Browse through you smelt material and remove suspect WW's and other items. KEEP THEM....but smelt them alone in another batch of smelt.

When I am smelting 'bad news' stuff...which, really, is most of the time.... I too start with sawdust AND ELEMENTAL SULFUR mix. It is easily found at the nursery, in small bags...about 4 or 5 bucks each. Watch closely as at the end of the year,,,in autumn, you can find 'hard' packages on sale...left out in the rain and they get real hard and caky. No issues here... cloth rag and a hammer renders the 'brick' soft enough for my smelt pot.

I cover the bottom of my smelt pot with about 2 or 3 inches of sawdust mixed heavily with the sulfur. Or, a handful or two of sulfur. then I add my smelt material over the top.... then fire up the heat...on LOW... My smelt is usually,,,well...damp.... I water wash all my smelt item on the driveway the day before...wash out the mud, butts, trash... and let it stand over night if no rain in the forecast. I scrap it up the next day...dump in smelt pot a prepared as above...turn on the propane fire on LOW... So now...we are ready for TOXIC SMOKE..TOXIC FUMES...smoke like crazy and of course am OUTSIDE and now...we put on our safety gear...leather boots, Apron, sleeves..welding gloves, safety glasses and face shield....

Are we now beginnig to see the SMOKE..FLUE GAS...smell the sulfur?? let it go and stink!! (expect love letters from your HOA!) come up a bit on the heat...little by little....when you see some melted metal...with a long handle spoon...face to the side...stir...slowly...keeping your head BACK and I slip on an acid gas canister mask here too. Come up on the heat....add some more FLUX....still slowly.... let that sit and stinks about 30 minutes....stir...mix...come up on heat and wait.... let things 'cook down'....and NEVER,,<EVER...add any more smelt material to the pot...NEVER.......So by now we are a good 90 minutes in our smelting operation and the pot is all molten...scrap out clips and dross... sides of pot and bottom.... and check temp of smelt...should be around 600 to 700....not too hot... and now...add final flux of sawdust and sulfur.... get back...gonna STINK....still,,scrape...remove dross....

Once the smoking has slowed down.. and dross and grud are gone.... I finish with wax... I grabbed some toilet bowl wax rings a few months back and they are great.... stir...remove dross.... Bingo... I am ready to pour ingots.... I do not cast boolits out of the smelt pot....

the trick here gents...is fluxing and coming up slow on the heat in the pot...keep in mind...my smelt was water washed last night... I do get some popping but to date... because I come up so slow on the heat....not tinsel fairy...KABOOM.... and the burning flux helps remove moisture....

I never have tried the muratic acid trick...however I have heard the results are good. the magic stuff is the sulfur and I think the dry kind in my sawdust is safer. And I am very queasy about adding any liquid to my smelt pot. Once my pot is full... the only thing I add is dry sawdust and dry sulfur and wax....

So...again...that's my 2 cents and worth every penny!!

Nose Dive

Cheap, Fast, Good. Kinldy pick two.

[triggerhappy243]

who ever said to put muriatic acid in the melt?

[Nose Dive]

Triggerhappy 243..... Adding acid to our pots... muractic...sulfuric is discussed in the post shown below on this site. one below this one.

http://castboolits.gunloads.com/showthread.php?63082-Zinc-Removal-with-Sulfur-Report.

The sufuric adds the sulfur...does about the same job if you know when, where, how to get it in the smelt pots safely. I don't do it. Powder sulfur does the same job and is safer in my opinion.

Nose Dive.

Cheap, Fast, Good. Kindly pick two.

[GunStuff]

OK Hold it right here. The muriatic acid in the above web site was suggested as a way of checking a mix of wheel weights to see if any zinc ones are present. Yes zinc would react as opposed to lead BUT all of the iron clips in the mix would also react. Adding Muriatic acid was NOT suggested as a way of removing zinc from a lead alloy containing zinc. It was a stupid suggestion coming from a physics teacher with obviously no clue of what is in a bucket of wheel weights.

Muriatic acid is a water solution of hyrochloric acid (HCl). In its anhyrous form HCl is a gas at room temperature. You be the judge if the water or HCl will stick around until the lead melts.

[Nose Dive]

GunStuff... Mmmmm My response was targeted to the question---"who ever said to put muriatic acid in the melt?"--- (see the word 'who'?)

My response was..to see the post...on this site that discusses adding acids, bases, plumbing solutions, to our smelt pots.

Triggerhappy243, you, any reader can go to the thread, (again shown below), to see "who ever said to put muriatic acid in the melt?"

http://castboolits.gunloads.com/show...-Sulfur-Report (http://castboolits.gunloads.com/showthread.php?63082-Zinc-Removal-with-Sulfur-Report).

The need, the usability, the desired results, the reactivity, and applicability of adding these solutions to our smelt pots was not questioned.

Where to find the "WHO" was the response. I believe, if one reads the thread, one can discern the 'who'. And, I am sure there are other locations where adding reactive solutions to smelt pots is discussed. And, there too, the WHO, to me, would be important. As, an unskilled or neophyte smelter could be lead to concoct a mixture in his pot that could lead to one harming ones self and/or others.

Your briefly stated analysis of the thread and the Chem 101 lesson in the reactivity chain, may or may not be astute. Again, only the individual reader can be charged to ascertain if the provided data is useful to his specific application.

Nose Dive

Cheap, Fast, Good. Kindly pick two.

[edctexas]

In some of my melting of ingots from smelting, I get some less than BB sized balls that are shiny floating on the top of the melt. The lead temp is 715F. Should I try to flux those tiny balls with beeswax? There are only one or two when adding several 1 lb ingots to the melt.

Ed C

[Nose Dive]

edctexas... In my opinion, in your casting pot I assume, the wax trick my indeed help get rid of the little BB's. Depends on what they are.

When I see 'things' appearing in my CASTING pot, I swish a bit with wax and see what happens. Rarely do i see 'particulate' matter appear in my casting pot, but, I do as a routine add WAX... I am not that exotic to add beeswax to my casting or smelt pots as to me, it is a bit out of my budget. I use any wax I can get my hands on to flux or reduce nasties in my pots. I save the beeswax for my mix for lube. And, I do not add my sawdust flux to my casting pot as I try to keep it somewhat clear and clean. If I find I have a 'bad smelt' ingot in my casting pot,,,,which indeed is quite often as I smelt a lot of 'road trash' and corruption.....I just pour the stuff out of the cast pot back into ingot mold to be 'resmelted' as discussed below....

You didn't mention how aggressive you are in fluxing and mixing during smelting. Here, during smelting, is where i get 'happy' with sawdust and sulfur mixture to mix in my smelt pot. Usually do this three or four times at least. Mixing well all the time and at the temps you show. And, in the smelt pot, i always finish with a good dose of wax. I scavenged about 15 or so wax toilet rings from an apartment demo site back during the summer. After the top floor was demo'ed, i went back and got about 25 more from the ground floor. I also get some drippings from a church. They burn alot candles and don't mind me gathering the drippings. Wife burns scented candles and I always get some 'left overs' out of the bottom of those candle jars. I also find some form garage sales and Good Will. There, i gather a few pieces and offer about 50% of the total 'asking' price. Rarely am I turned away as I have cash in hand.

Now beeswax is a better material that I 'pay for'. That is, give green money for it. This is used for my boolit lube mix. I deem it 'expensive' and keep it out of smelt and casting pots. My lube recipe is sweet enough to be blended on the kitchen stove or a hot plate in the shed.

I would suggest you go to HOBBY LOBBY and get some wax blocks....the ones they sell to 'candle makers' ....this way, you are paying for wax and not 'candles' made by wage earning person's that you have to pay for.

Give it a shot. See what happens. And then let us know how it went.

Nose Dive.

Cheap, Fast, Good. Kindly pick two.

PS: if you flux with sawdust/sulfur, be sure to read on this site how, where, when to do this. SMOKES LIKE HECK..STINKS...and fumes are 'BAD NEWS" and must be done outside.
PSS: one last suggestion...DON"T flux with sawdust/sulfur on a nice Sunday after noon in your back yard while neighbors are outside Bar-B-Quing. YOU will be told very quickly 'where to go'..and be queried by several citrus questions posed as to the degree of your intelligence. (ask me how I know)

[Don Fischer]

Boy this is an old one. I didn't read the whole thing so if this has already been sorry. I smelt my lead and turn it into ingots. To smelter it I use the melting point of the lead. I think it was something like 650*. The zink will not melt that cool so it floats to the top and is skimmed off. Same with the WW clips. Only place I've found zink is in WW but then again WW are what I mostly use. Oregon outlawed lead in WW so finding them around here is a lost cause. But I've got a life time supply of ingot's on the place!

[Don Fischer]

The process is done by slowly and in a very thin stream, pouring the molten metal into a pail filled with ice cubes. HCl will dissolve the zinc, but it will make a very big mess of the lead forming lead choloride. That's a big mess to undo.

Pouring melted lead on water? It doesn't explode?

[Djei5]

Pouring melted lead on water? It doesn't explode?
Pouring water into melted lead does.

[AllanD]

OK Hold it right here. The muriatic acid in the above web site was suggested as a way of checking a mix of wheel weights to see if any zinc ones are present. Yes zinc would react as opposed to lead BUT all of the iron clips in the mix would also react. Adding Muriatic acid was NOT suggested as a way of removing zinc from a lead alloy containing zinc. It was a stupid suggestion coming from a physics teacher with obviously no clue of what is in a bucket of wheel weights.

Muriatic acid is a solution of hyrochloric acid (HCl). In its anhyrous form HCl is a gas at room temperature. You be the judge if the water or HCl will stick around until the lead melts.

Muriatic (Hydrochloric) acid will have only a small effect on lead at normal temps (attempting to clean lead flashing with HCl is a long slow process that would test the patience of any saint you care to name), it's main effect on steel and Iron is to rapidly remove any Oxides present, Ferous (III) Chloride is a bright yellow in aqueous solution, and is rather different than the fizzy, fuming fire monster (From liberated Hydrogen) that HCl reacting with zinc is...

Straight HCL is one of the best acids to clean your empty (Cold) melting pot...

[AllanD]

Not sure if road flares have any sulfur at all but they do have a lot of Strontium nitrate and wood meal. The wood meal provides a fuel and the Strontium nitrate is an oxidizer and colorant. It makes the flame red. I do believe there is pvc included too as it makes the color brighter and more red.



Frank

Frank,

Nobody intentionally burns PVC (at least not where the EPA will ever hear about it)
because burning PVC produces PCB's and Dioxin and several other such nasties...

Allan

[Traffer]

I recently used sulfur to remove possible zinc contamination. The sulfur seems to have ruined the batch of lead. It kept "taking more" so I kept adding more. When I had removed almost half of my batch in black and dark grey slag, I began to think, "maybe I am just making lead sulfate here". I tried melt down some of the slag and got a small amount of lead that has very large crystallization. What is left of the batch is now harder than when I started. I don't know if it will flow well, I can't use it because I need soft lead. Also, my recent ingots have a sour smell. I know that lead does not have a smell but these definitely smell sour. I am perplexed about all of this.

[Don Fischer]

Is this zinc coming from wheel weight's he smeltered? If so, its easy so separate to separate zinc from lead. Melt the wheel weight's at just over the melting point of lead. I think I melted at 600*. Anything that float's get's dumped.

[Traffer]

Is this zinc coming from wheel weight's he smeltered? If so, its easy so separate to separate zinc from lead. Melt the wheel weight's at just over the melting point of lead. I think I melted at 600*. Anything that float's get's dumped. I am more interested in how to get rid of the sulfur at this point.

[triggerhappy243]

[QUOTE=AllanD;3578319]Frank,

Nobody intentionally burns PVC (at least not where the EPA will ever hear about it)
because burning PVC produces PCB's and Dioxin and several other such nasties...

Now here is an evil thought............... we want our lead back. so lets make a deal with the epa. Give us our lead back or we will start burning PVC. (SORRY, I DONT KNOW WHERE THAT CAME FROM). But who knows.

[triggerhappy243]

I am more interested in how to get rid of the sulfur at this point.

I have not tried using sulfur, yet, is it possible to use too much?

[Traffer]

I recently used sulfur to remove possible zinc contamination. The sulfur seems to have ruined the batch of lead. It kept "taking more" so I kept adding more. When I had removed almost half of my batch in black and dark grey slag, I began to think, "maybe I am just making lead sulfate here". I tried melt down some of the slag and got a small amount of lead that has very large crystallization. What is left of the batch is now harder than when I started. I don't know if it will flow well, I can't use it because I need soft lead. Also, my recent ingots have a sour smell. I know that lead does not have a smell but these definitely smell sour. I am perplexed about all of this.
I tried resmelting some of the wheel weight possibly contaminated lead that I previously tried using sulfur on. I am going to try and describe just exactly what I did so maybe someone can help me out here. I bought about 8 lbs of WW on eBay. The guy said that there were no zinc ones in it. I melted it down (I do not have a thermometer) and got a batch of pretty hard lead. I tried using it and it worked OK but not great. I am sure it was way hot enough to melt zinc. I used it again a couple of times and it seemed not to flow to well. Then I read the thread about sulfur. I don't mind experimenting so I bought some clay-sulfur at the garden store. I separated the sulfur out by literally picking out the little yellow balls from the brown stuff. I got about 6 oz of what I think is sulfur. I melted a small pot full of lead (about 4 to 5 lbs) and added about 2 tbsp of the sulfur. I put it on top and then pushed it under with a spoon with holes in it. I had the spoons tied to 4 ft sticks and I was wearing a respirator and was up wind while doing this. The sulfur burned, it bubbled in the lead creating big lead bubbles, then the lead that was in contact with the sulfur turned to a bubble gum like consistency, then it got harder. I kept mixing it until it turned to grey-black powder. A LOT of grey-black powder. I kept adding sulfur expecting it to stop "taking" it. It didn't stop taking it. I ended up using about a half a cup of sulfur in that 4 to 5 lb batch of lead. I piled the dross in another container to re-smelt at a later time. YOU CANNOT BE TOO CAREFUL WITH THE FUMES. I got just a whiff through my respirator and that even made me sick. Any way I made a few small ingots of the stuff and tested it for hardness. Hardness was the same, about 11BHN. The ingots seemed to cool with large crystals in places, kinda like cast iron. I can't use 11BHN. So my experimenting with it stopped. I did go back however and try to glean some more lead from the slag pile. I put in about 3 or 4 cups of slag and eventually got a small chunk of lead, about 4 oz. Oddly that lead had a kind of gold sheen on the surface and it ended up being 8 BHN. So because of that "luck" I took about 4 lbs of the previous sulfur-smelted lead and tried sulfur smelting it again. It went the same as the first time. Lots of sulfur, big bubbles, bubble gum consistency then black powder slag. But the lead poured beautifully and the ingots are very fine, no bubbles or large grain structure. It is 11 BHN though. So, I give up. This 11 BHN lead looks really nice but it is too hard for me. So I thought I would trade it to someone for some softer lead. Any ideas or comments?

[triggerhappy243]

Traffer, did you have the lead xrféd before you put the sulfur to it?

[Traffer]

Traffer, did you have the lead xrféd before you put the sulfur to it?
What is xrfed?

[badbob454]

scanned with a machine, to check alloy content.

[triggerhappy243]

most competent metal recyclers have them.

[Traffer]

I doubt if there are any around here. Besides I am dealing with a total of about 7 lbs of lead.

[triggerhappy243]

there are several members here that have access to the xrf gun. you could send a sample to them and they will have it tested. far better plan then to waste all that time trying to cook off the zinc that might not exist.

[Nose Dive]

Hmmm at February string ... about sulfur... Well... .it is NOT A CURE ALL FOR a good BRN... and not for pourability of the alloy...

I USE SULFUR in my SMELT pot and not in my casting pot. I do not alloy mix in my casting pot either....

So...here is my methodology...

I mix sulfur from the nursery in with my sawdust from my table saw. Put in bottom of smelt pot...and smelt...bring up temp and mix....

Say... three hand fulls of sawdust and one of elemental sulfur...mix it up in a cold smelt pot...cover to top of pot with smelt material...heat up...

SMOKE...smell...noxious fumes... mix things up.... have a 'filter' dipper and screen clips...zinc...trash...corruption.... stay UNDER 700F....stir..mix...

Ok...all smelt is melted...stirred up nice....now add more sawdust/sulfur and mix again.... mix....screen...clean.....

NOW...at 700F...bring up heat to 800 or so...and you guessed it...ONE MORE TIME!! but this time only sawdust and mix and screen well.....

Mix...strain...scarpe bottom of pot... at 800...after all dross is gone...I add a heeping hand full of wax and mix well again... look out..flames!!

So now...you are cool with zinc...you strained and fluxed it at 700...so ...why add more flux...you have done it four times...

Here... I alloy...add tin...I like PEWTER better.... mix it well... and stay around 800....NOT TOO HOT... Time to pour out into biscuit tins....

Yup... pour it out and let it cool...then BRN test... If to hard or too soft... ALLOY IN CLEAN SMELT POT...not casting pot...get it right first...

SO now you have casting ingots and get after that....

no need to go crazy with the sulfur if you flux with it at smetling time!!

Nose Dive

Cheap, Fast, Good. Kindly pick two.

PS; Guys...go back to page four...read all the discussion there too. ND

[AJG]

why would you get the Zinc out?
I have about 1/4 of all my wheel weights Zinc WW and the rest is lead (what melts).
I get wrinkled bullets and 3 of 6 cavities are filling correctly but who cares.
I can live with wrinkled bullets.

More of it seems Zinc is better for the Barrel than even lead. It is harder than lead but softer than copper. If left unsized it should fit perfectly and I Experiment no leading.
I use Lithium grease as bullet lube.
Just leave the Zinc in the lead and learn to cast it. It makes for usable bullets.

[spqr]

i stumbled into your thread while looking for zinc solutions. really helpful info, so i registered.
last weekend i polluted a 50lb smelting pot of nice range lead with some boneyard "lead". My buddy that owns the place gave me about 100# of scrap non ferrous they had been collecting since the 70's. Most of it was wheel weights i have since used. I came across big 3 ingots that looked a lot like Lyman casts, just a little different look. And a round diski assumed was plumbers lead. Looked like lead, and heavy. I assumed they were all lead. Mistake. I added them to the 50# i had molten, with about 6 oz of tin. Noted the constant oatmeal pooling at the top. I avoided it best I could, made about 2000 swc 45s and the rest into cupcake ingots for later. When I cast the 45s the mix flowed decent enough, I just had to keep ladling from below the oatmeal surface. They looked fine until they cooled. Then some of the bullets wrinkled. After the ingot "cakes" cooled I dumped the pan and noticed the hexagonal sparkle on the bottoms. They also bounced of the floor. Not the solid thump i expected. All ruined, probably way too high % zinc. I have been going through the bullets, about 10% are visibly wrinkled and were discarded. I sized the clean ones and they are going through my Lee .452 sizer in typical fashion. I sampled the usable ones and did a vice "hardness" squeeze against some old stock from a previous batch. Exact same hardness, or should i correctly say "softness". i have found "soft" does not lead the barrels at all. I guess the moral is, keep the temp down and avoid the zinc at the surface. Or avoid the zinc altogether. And yes, I cast right from the smelt pot. I am not a purist. I have a full time job and barely enough time to cast. I have pushed out around 10,000 very clean bullets in this manner in the last year and half, 3 of us fire these weekly and have had excellent groupings and no leading (2 1911s and a SW M&P) with 5.7 Unique and Alox ring 200 gr. bullets. No more mystery metals into the mix though. No disagreement with the previous post, I could load the hard wrinkled zinc/lead bullets, but I shoot at an indoor range and have seen chunks travel 30 feet back. I would be worried the zinc-based bullets would bounce too much.

[triggerhappy243]

spqr, for the cost of 1 pound of clean lead, and a penny sized splatter of your problem lead, you can have bne do an xrf test on your mistery lead. you can also put a few drops on the suspect metal of muriatic acid (aka pool cleaning acid). if it foams, it has zinc.

[Oklahoma Rebel]

AJG, not to be rude, but it sounds like you don't know what you are talking about, and you might give some newcomer the wrong advice. anything more then a few percent zinc is really going to mess with your casting, and boolit weight, and your lube may work for 800fps 38spls. but if someone listened to you and used it in their rifles they are in for a lot of cleaning. lithi-grease does make a good INGREDIENT for boolit lube. pls learn some more before giving out tidbits of wisdom!

[spqr]

An update. I am learning as I go.
The slightly "wrinkled" bullets I thought might be polluted with zinc were sized and then weighed and are right on spec. And they are relatively soft, virtually identical to previous "clean" batches. I suspect I was casting at way too high of a temp, as some of the wrinkled bullets dented/ deformed when they hit the soft board tabletop i drop on to (yes, i dont drop into water). They were evidently still semi molten coming out of the mold.

I couldnt bring myself to discard 50# worth of ingot, even though I was sure it has zinc in it. I did not want to get into sulfur, so i tried again with the smelt pot but at a much lower temp. It took a while to bring it to a molten state, but then I immediately reduced the flame once it had melted down. As I stirred, quite a bit of silver-grey oatmeal formed at the surface. After quite a bit of diligent skimming, I had quite a pile of zinc-like material in the discard pile. Probably 5-7 lbs. Crunchy brittle oatmeal. It is nowhere near as heavy as lead would be, so I am confident in what I removed. As a test, I cast about 50 swc from the pot so i could hardness test. Damned if they were not the most beautiful silver. Weight is correct. Hardness test in the vice was spot on. The rest of the pot i cast into ingot cupcakes, and they are the right color, no galvanized sparkle, and they "thud" on the floor, not bounce. yes i drop the cupcakes and listen/watch. I do need a life.
I consider the evening a success. And some lessons learned: more heat is not better, avoid mystery metals, wrinkles are the fault of the person casting, not the metal.

[Oklahoma Rebel]

that oatmeal is probably antimony, keep the heat up. a cold alloy and a cold mold make for wrinkles. if the weight is right it probably don't have much if any zinc in it so ya don't throw it away. get a thermometer and keep the alloy at 675-700 and after a few throwbacks your mold will warm up, wait a second or two after your sprue hadens before you cut it. just make notes of what works and what doesn't, you'll get it! good luck-Travis,oh, that stuff you skimmed, pour muriatic ( hydrochloric acid) on it. if it fizzes it is zinc, if it don't it is antimony and you need to flux it back in. if it ends up as antimony pm me and i'll let you know how to get it back in.

[AllanD]

"flowers of sulfur" is more technically known as "sublimed sulfur", aka sulfur condensed from vaporized (converted to gas form) sulfur, it is basically "Distilled" sulfur and is the purest form generally available in commerce.

Nice to know that it can be used to strip Zinc from a melt, in my case especially convenient as I have a cardboard canister of the stuff (30some pounds)

In many parts of the world it is simply collected in "flowers" form as it collects on cool surfaces near Volcanic Vents , geysers and fumaroles.

[popper]

Just add clean alloy until the Zn is low enough to cast well.

[TheGrimReaper]

I went to the Sanders Lead Company in Troy, Alabama a few years ago. They have an industrial tower/bui9lding that looks like a cracking tower found in oil refineries. One of the Engineers told me that they bring in scrap lead and then heat it up to 2300 Degrees Fahrenheit and separate ALL the various metals from the lead.

They sell their pure lead in 60 pound ingots and will actually give you a computer print out of all the metals in it. Their "Pure" lead is around 99.96% pure if I recall correctly.

I need to check this place out. Sounds like a really neat experience.

[Smoke4320]

spgr .. sounds like you are on the right track ..
before long you will be a expert

[AllanD]

Something similar is used in refining. Zinc is added in the refining process. Gold and silver are very attracted to lead, much more so than the Iron sand in which they are usually found. Zinc s added in the molten state after the iron is removed and melted in, as zinc is around 3000 times more attracted to gold and silver than to lead. The zinc then forms a dross on the top as the pot cools, and is skimmed off. Then the zinc is then boiled from the silver and the gold and recovered for reuse... Charcoal or coke is used to rid the lead of the zinc.


If it were not for the usual of amount if Silver found in Lead Ore it would be financially Impractical to mine or refine lead ore.

The Silver extracted during the smelting/refining process pays for the entire effort and any refined Lead produced is 100% profit... all due to the fact that Silver is 3000 times more attracted to Zinc than to Lead. any Gold or Platinum recovered is a "gift from God"

[trentvb]

I think I got lucky by not really knowing what I was doing, but, the electric coil I use to heat the pan to melt down my wheel weights gets just hot enough to melt the lead but not the zinc. Saves me the trouble if I miss a few in sorting.

[Cosmic_Charlie]

Will an infrared thermometer work on a smelting pot? My analog thermometer is too short to be very useful away from the casting pot.

[caffe]

your tin and antimony, assuming that there IS any in WW anymore, is on top, so skimming will remove it and you need it for 9mm, at least, and magnum loads. I use a ladle and a propane fired furnace, so keeping the top of the melt occluded will not work for me.

[dondiego]

your tin and antimony, assuming that there IS any in WW anymore, is on top, so skimming will remove it and you need it for 9mm, at least, and magnum loads. I use a ladle and a propane fired furnace, so keeping the top of the melt occluded will not work for me.

Metals don't separate like oil and water. It is a true solution like salt and water. There may be a little Sn/Sb oxidation on the surface and the hotter the melt the more oxidation. Add some wax or sawdust and mix well.

[notenoughguns]

your tin and antimony, assuming that there IS any in WW anymore, is on top, so skimming will remove it and you need it for 9mm, at least, and magnum loads. I use a ladle and a propane fired furnace, so keeping the top of the melt occluded will not work for me.

????????? where did you learn from ??????????

[Traffer]

Metals don't separate like oil and water. It is a true solution like salt and water. There may be a little Sn/Sb oxidation on the surface and the hotter the melt the more oxidation. Add some wax or sawdust and mix well.

Thank you for helping steering this back to reality. These conversations can go sideways quickly and end up promoting nonsense. Let's keep these things in the realm of reality.

[dondiego]

Will an infrared thermometer work on a smelting pot? My analog thermometer is too short to be very useful away from the casting pot.

I don't have an IR thermometer but I have read that the shiny surface of the melt interferes with the IR meter which gives invalid results.

[Cosmic_Charlie]

I had a 60 pound smelt go South because a serving platter I thought was pewter has some zinc in it. I used sulphur and sawdust, kept the heat up and it cleaned up great. Did it outside on a day with a steady breeze. Managed to do it without a respirator but the little I did breath in convinced me not to go without one next time.

[Traffer]

An update. I am learning as I go.
The slightly "wrinkled" bullets I thought might be polluted with zinc were sized and then weighed and are right on spec. And they are relatively soft, virtually identical to previous "clean" batches. I suspect I was casting at way too high of a temp, as some of the wrinkled bullets dented/ deformed when they hit the soft board tabletop i drop on to (yes, i dont drop into water). They were evidently still semi molten coming out of the mold.

I couldnt bring myself to discard 50# worth of ingot, even though I was sure it has zinc in it. I did not want to get into sulfur, so i tried again with the smelt pot but at a much lower temp. It took a while to bring it to a molten state, but then I immediately reduced the flame once it had melted down. As I stirred, quite a bit of silver-grey oatmeal formed at the surface. After quite a bit of diligent skimming, I had quite a pile of zinc-like material in the discard pile. Probably 5-7 lbs. Crunchy brittle oatmeal. It is nowhere near as heavy as lead would be, so I am confident in what I removed. As a test, I cast about 50 swc from the pot so i could hardness test. Damned if they were not the most beautiful silver. Weight is correct. Hardness test in the vice was spot on. The rest of the pot i cast into ingot cupcakes, and they are the right color, no galvanized sparkle, and they "thud" on the floor, not bounce. yes i drop the cupcakes and listen/watch. I do need a life.
I consider the evening a success. And some lessons learned: more heat is not better, avoid mystery metals, wrinkles are the fault of the person casting, not the metal.

Keep it up...you are learning the same way I did and most of us here. I never throw away stuff ...later it may come to be useful. One fyi:
IF you find that your molds are not filling as well with your "cleaned lead" Add about 1% tin or pewter. Tin can be pulled out when you try getting other stuff out like the zinc stuff you got. But it doesn't matter at all if your bullets are still filling the mold. Tin IS ONLY NEEDED when you cannot get get good fill (or if you are an expert and using it to help get stuff like copper and antimony to play well yadayaya. Only the high pressure guys mess with that.
PS I don't water drop either. I have a towel folded up in a box that I drop them on...gotta be cotton... They hit and don't deform.

[meeesterpaul]

Fertilizer. Sulphur for gardeners, cheap.

[Flogger]

I would like to remind folk, as is was mentioned, that sulfur is commonly used as an insecticide. As simple as flowers of sulfur, in a box, with a wick. You will have bugs falling from the sky- or at least the ceiling. Make sure you are not downwind, and have lots of ventilation. Lots and lots.

Sulphur isn't actually an insecticide but combined with other chemicals it is used in insecticides. sulphur is most commonly used as a soil amendment to adjust ph levels.