Possible to separate alloy?

[Thompsoncustom]

Just like the title says I was wondering if it would be at all possible to separate the metals in wheel weights? I think it would be really nice to be able to split them and add as needed to lead and have an accurate knowledge of what is all in the alloy. Also this has to be somewhat do able without a chemist lab.

[btroj]

It is probably possible, on an industrial scale.

For our purposes they are in a non separable mixture.

[geargnasher]

Like Brad said, forget it. About the best you can do is make large, consistent batches of your alloy and have asample assayed by a company like Rotometals, then add known components if necessary to make it what you want exactly.

Gear

[AndyC]

Someone here once said that it would be like trying to get the tonic back out of the gin - or some mixed drink like that, anyway ;)

[btroj]

That is exactly right. It is possible, just not at all practical for our needs and abilities.

[geargnasher]

Once the tonic is in the gin, add a key lime wedge or just drink and enjoy the way it is! Same with scrap lead.

Gear

[Thompsoncustom]

alright I figured it was possible but was probably not really doable or at least fees-able. Thanks

[Hammerlane]

If it was as easy. We all would be casting the perfect bullet, Dream on

[Thompsoncustom]

I wasn't looking for a easy way just a do able way tho easy would be nice. From what I have read lead dissolves in nitric acid so it might be possible to separate some of the metals that way as long as they are not soluble in the acid as well.

[btroj]

Tin and antimony will dissolve in nitric acid as well. Many moons ago I used nitric and hydrochloride acid together to dissolve a bit of a wheel weight and some of each of the three metals in question. Is was done as part of an instrumental analysis lab while in college. I took heat and a bit of time to get them into solution.

Based upon the memories this is not a practical home type of thing. Concentrated acids are nasty as all get out. I don't even know what could be used to reduce the metals back out of solution.

This just isn't home practical. Not at all.

[Thompsoncustom]

I guess we have different idea's of what is do able at home I don't even consider it that big of deal. I have some stuff just laying around like 5 pounds of sulfur, potassium nitrate, 5 gallons of sulfuric acid, and probably some other stuff but I wouldn't consider that a chem lab by any means. It looks like you could probably get the job done if you used enough different acids as things like arsenic are not soluble in HCI and Cadium is slow dissolving in HCI. Tho it looks like antimony and tin dissolve in both HCI and nitric acid.

[btroj]

You still have the matter of scale. If you can dissolve a 1/2 ounce of lead per ounce of acid that means you can get about 4.5 pounds dissolved per gallon of acid. To get 100 pounds you will need around 20 gallons of acid.

You the need an equally large volume of whatever you are going to use to reduce the lead back out. This doesn't even take into account the other things used to separate the various metals via precipitation.

While this may be a lab curiosity itis most certainly not home doable. The cost would quickly get out of hand not to mention how you plan to get rid of the various toxic wastes.

I urge you to give up on this idea. It sure seems like a good way to learn what the entire weight of the EPA feels like. Can you say superfund site?

[Casting Timmy]

You can seperate it a little into two different mixtures without too much effort. If you've ever watched your lead in the last few minutes before melting, you probably noticed that it's a slurry or a slushy like consistency before coming completely liquid.

If you can hold the lead in this temperature range while it's still in a slushy mixture (liquid and solid mixture) you can seperate it by scoping out the solids and leaving the liquid behind. This can get easier with a PID controlled set up so that you only have to wait until the pot is at the correct temperature.

You can also get really fancy with this and try and pull out a lead/tin mixture closer to something you would like to use in making your boolits. If you look at a lead/tin phase diagram you will notice a the lines across the top where it transitions from a pure liquid to a liquid/solid mixture. Once you're inside this area draw a horizontal line for the temperature you;re holding your lead at. Then draw lines straight down from where this horizontal line crosses the liquid line and the solidus lines. This will tell you the alloy compositions of the solid and liquid portions of the mixture.

The closer your mixture is to a pure alloy the harder it will be to hold the temperature of the mixture in the liquid/solid mixture.

This of course is complicated even more as more alloying agents get in the mixture, but the concept will still work unless it's a eutectic alloy that goes from liquid to solid without any transition through the liquid and solid areas of the chart.

[Thompsoncustom]

Could you separate it by melting points? Sense it's an alloy and not pure the melting point of each would be off but pure tin has the lowest so wouldn't that be the first to melt off?I've seen the slurry when melting but I have never tired to hold it. This seems like an easy method if it works well.

[cbrick]

No, not so easy. The first problem you'll run into is that every single alloy will have different melt temps. Next is the fact that home casting posts will not hold the temp at the exact temp you need, you would have a couple of minutes to scoop from the top of the pot and even if you turned off the pot the temp is still rising past your needed temp. Then with the power turned off the temp will decrease and again past your desired temp. Next, you'll only ladle off the top and that will be a small percentage of the total metal that's in the alloy, the rest is still in solution.

I reduced (but did not eliminate) the Sb percentage of an alloy once doing this and found it impossible to reproduce, never managed it again. Seems the temp has to rise at a specific rate depending on the exact percentages and type of metals in the alloy.

Good luck should you decide to attempt this experiment.

Rick

[btroj]

Google lead smelting. It is currently done in many places via a blast furnace. The molten metal is held in a molten statin an atmosphere that allows for production of antimony oxide which won't melt and can be skimmed off. Then other means are used to remove the other metals..

This doesn't seem very practical for us as we don't have the necessary technical knowledge on what temp or "atmosphere" is required. when you look at the fact these methods are used to smelt down current production batteries which are dangerous as heck for us to even consider using it tells me industry has means way beyond us.

Like Rick said, you can remove some metal via oxidation butit is going to take time and energy. Heat the metal on a burner for a couple hours and skim the surface every ow and then, you will remove tin and antimony. Key thing is, how much? Was the time and fuel cost worth it? Would it have been easier to Jair dilute the alloy with some pure lead?

[Casting Timmy]

The alloys that seperate won't be pure tin or pure lead, even if it's a lead/tin mixutre. If you look at this chart, you can see how the lead and tin change during cooling.

http://www.sv.vt.edu/classes/MSE2094_NoteBook/96ClassProj/examples/bethcon.html

Click on the phase diagram link on the page

There is a vertical line at a 40% tin mixture and a 60% lead mixture. If you follow this down it will cross the liquidous line and come to teh second dot from teh top. At this point the mixture will be mainly liquid with a little solid portion to it. If the mixture is continued to cool it will come to the third dot down from the top and you can see how the example works on this page.

So at this point you can find out the composition and also the percentage of liquid and solid to the mixture.

This does get more complicated as your alloy will also have a lot of other stuff in it. Just keep it simple and think of it as a lead/tin mixture.

An electric pot will be the easiest method to do this, just melt it and then turn down the dial a little and wait for a little while. Keep repeating this until you get a temperature in the liquid and alpha phase.

If you're melting over gas, this will be a little harder, but I have seen the liquid and alpha phase in my gas smelter a lot unfortunately. Seems sometimes I could use a little more heat to melt my lead, but since I don;t have enough heat at times I just wait a little longer for it to melt. I never turn my gas on too high when smelting though, I keep it pretty low as I don;t mind waiting a little bit for it to melt everything down.

[Sonnypie]

Once the tonic is in the gin, add a key lime wedge or just drink and enjoy the way it is! Same with scrap lead.

Gear

Add a lime and drink it!
Well, I suppose.
If you have brass lips and a cast iron stomach.
Better check for a SS orifice....
That stuff is HOT when it is at the "drinkable" stage! :drinks:

OP,
Tell you what, you send it to me and I'll separate it.
You won't have it, and I'll have separated it from you.
Such a Deal!

Holy Mazola oil! [smilie=1:

[badbob454]

if all metals could be slowly raised to the boiling point perhaps one could collect the molten steam at different boiling points,(read temperature) , to seperate the heavy elements ? just as distilling the gin from the tonic?all these metals will have a gaseous stage would they not? and a t different temperatures , .....
but i dont want to try it...

[Sonnypie]

Sometimes I have gaseous stages.
But I don't think you'd want to try those either, Bob. :lol:

It is true that different things will separate at temperature. That is what a cracking tower did (does?) at an oil refinery.
I sure don't know of soft metals would do that though.

What about a Buckshot mold? It could be disposed of an ounce at a time. :confused:

[Thompsoncustom]

I use the side burned on my grill to melt the weights into ingots and than I have a bottom pour for making bullets so I could use either one. I'll probably get out this weekend and do a little playing around with this to see how do able it is. Thanks for all the help so far.

[Oreo]

I think this is where I've seen people recommend selling what you have & using proceeds to purchase pure metals. Eazy-breesey. Probably way less expensive too.

[cbrick]

I think this is where I've seen people recommend selling what you have & using proceeds to purchase pure metals. Eazy-breesey. Probably way less expensive too.

Some people need to experiment & tinker with stuff. Nothing in the world wrong with that, I do it often myself, sometimes the "what if" gets the better of me and I just have to see for myself. I look at this as the education of Rick.

In this case I think he is up against quite a challenge plus he'll need to have the alloy analyzed before & after his experiments to know if/what he accomplished anything.

Just sounds like the "what ifs" has struck Thompsoncustom, that's not a problem . . . the education continues.

Rick

[Jeffrey]

I recall a way pure silicon crystals are made from a less pure MOLTEN silicon mixture. Seems like the temperature of the mix was brought just above melting point. An already pure silicon crystal was brought into contact with the top of the crucible. The crystal was raised, drawing a pure silicon crystal from the crucible. As said, not practical for our facilities, but refining can be done without acids. Jeffrey

[Thompsoncustom]

Ya you hit the nail on the head there I just love to tinker with stuff I have no reason to even be doing all of this really just want to play around with it and I did just that this morning with some interesting results. I took 3 ingot of clean wheel weight lead and melted them on the gas grill and melted what was in my pot. The lee bottom pour pot did not work at all because after it melted I could not get it cold enough to slurry even all the way down but it seems to work fine on the gas grille so I worked with the 3 ingots I melting into a slurry and skimmed out the top and set it a side and repeated this process a few times as it doesn't like to stay at a slurry so I had to adjust the heat up and down. After I had most of what I thought wasn't lead-tin mix skimmed off I melted the remaining lead and pour it in to my muff-tin ingot molds. Now this is where is get interesting I took ever thing I skimmed off and put it back in the now empty pot and tried to melt it all but I could not do it. I was getting the oatmeal effect though I was sure there was not any zinc involved but just to rule it out I flux it with some pure sulfur and nope it wasn't zinc. I also used my hand torch to heat it up to probably 1000 degree and still no luck so I'm guessing that what ever I skimmed out is in to high of concentration to be soluble in the lead. Also I should note that I tired to flux it in several time with no luck. So I skimmed the oatmeal looking stuff out or at least all of it that I could which was probably around 90% and set it aside.

About as far as I got today I did cast some bullets of the 10% oatmeal mix and they seem to turn out fine but I have yet to do anything with the lead-tin or lower melting point mix that I separated off in the beginning.

[Defcon-One]

Send it out for this process!

Pyrometallurgical Refining

Pyrometallurgical Refining is performed in liquid phase, which means that the crude Lead must be melted to temperatures from 327ºC (Lead fusion point) to 650ºC. As a general trend, the process is performed in batches of 20 to 200 tons, according to the refining plant capacity. The chemical concept behind the refining process is the addition of specific reagents to the molten Lead at proper temperatures. These reagents will then remove the unwanted metals in a specific order as they are added selectively.

Copper (Cu) is the first element to be removed with elementary Sulphur in a two phase procedure. In the first step, almost all copper is removed as a copper sulfide (CuS) skims when elementary Sulphur is added to the molten Lead at 450ºC. The second step is meant to remove all remaining copper by adding small amounts of elementary Sulphur to the molten Lead at 330ºC until no reaction takes place anymore. Tin (Sn) is next removed by either chlorine (Cl2) or ammonium chloride (NH4Cl) oxidation. The addition of chlorine to the molten Lead at 500ºC produces tin chloride (SnCl2) skims which are mechanically removed. Although this is the current method for tin removal, its inconvenient is the parallel removal of small amounts of antimony (Sb) and arsenic (As) by oxidation.

Arsenic (As) and antimony (Sb) are selectively removed by oxidation with either air enriched with oxygen (O2) or a mixture of sodium nitrate (NaNO3) and sodium hydroxide (NaOH). The temperature of the molten Lead is raised to 550ºC and a flow of O2 enriched air is bubbled into it. The reaction is extremely exothermic and the temperature easily reaches 650ºC. Those skims are a mixture of oxides (25% Sb, 10% As and 65% Pb).

Silver (Ag) come next and its removal is carried out by the Parkes Process, which makes use of the preferential solubility of silver in molten zinc (Zn) instead of molten Lead (Pb). Therefore, metallic zinc (Zn) is added to the molten Lead at 470ºC and the mix is allowed to cool to 325ºC. A silver –Lead zinc alloy separates and forms a crust on the surface. The crust is removed and the zinc separated from the silver by vacuum distillation. The crude silver is further refined using oxygen to produce fine silver. The excess of zinc is removed from the de-silvered Lead by vacuum distillation and then by Sodium hydroxide (NaOH).

Oh, don't try this at HOME! If you do, it will probably kill you by step 2 or 3.

[btroj]

An interesting experiment but how do you know what you have? Did you remove anything? Without an actual assay you just don't know.

I woder what the purpose of all this is? Removing tin and antimony seems silly as those are the metals we want in our lead.

I understand wanting to tinker but for what purpose?

[Sonnypie]

Does anybody know the Brinell Hardness of hot glue? [smilie=p:

[Mooseman]

Does anybody know the Brinell Hardness of hot glue? [smilie=p:

.0000000000000000015324 :groner:

[Defcon-One]

Mooseman:

Hate to do this, but you missed by two (2) zeros. Should only be 15! [smilie=1:

I love this stuff!