Render "dros" and what do Ya get?

[prs]

When I was using rendered wheel weight metal I would occasionally remove the thick layer of ash and dust from organic flux and clay granules I used to reduce oxidation. Bear in mind I flux and reduce often and am also meticulous in rendering scrap to have clean ingots. I would put the contaminated ash and such in a small can, when full that into another closed container and off with the household trash. There was some metal in it, probably some valuable tin, but the mystery of what else discouraged my will to reclaim.

Past couple of years the local WW supply has dwindled and what I could get had a lot of weights that were not lead alloy. So I concentrated more on collecting lead sheeting, plumber's pig lead, and buying tin and RotoMetals Super Hard and some other of their foundry metal.

After several hundreds of pounds of boolits cast, I had a quart or so of char and dross with some "good" metal clinging within the matrix. Since the sources were known and little if any worry about zinc and such nasties, I decided to attempt a re-rendering of the crapolla. I did the dirty dead in my 20# ladling pot which just did hold the whole quart. It heated up until the top most layer was glowing red, thermometer read 800F. I backed down the heat and waited for it to fall to 725F. I added 2 ounces of TCW-3 outboard motor oil and stirred until the smoke stopped, then I added a quarter cup of very old rice the cook no longer trusted, stirred this for about 2 minutes when the smoke burst into flames. Kept stirring until the show was over, then repeated the oil treatment to further cleanse. When the dust and char was carefully spooned away the waste in the old can had only a tiny trace of metal and I ended-up with 2 1/2 pounds of clean and pretty mystery metal.

This all occurred in the past couple of hours. The Lyman mold ingots have a nice "ring", they do not scratch with finger nail, are as pretty as you would please with out any indication of zinc or such. I hope it is a rich sn/pb/sb alloy. Buy how would I know? Test the hardness after it ages a bit? Don't worry about and add it a bit at a time to future casting sessions? I am inclined to that last option unless warned not to do so.

prs

[MaryB]

I would add it back to wheel weight batches to bring up the hardness.

[bangerjim]

Only way to know is to get an xray analysis at a scrap yard. You could have anything in there!

BTW......I throw that garbage away!

bangerjim

[littlejack]

+1 on what bangerjim said.
I removed the dross from my melt for a reason. I don't want to remove it again having put it BACK into my new alloy.
Why would I?

[Sasquatch-1]

You can use the muriatic acid test. Take and scrape some off the ingot with a file and put a drop of muriatic acid on it. If it foams you may just want to throw it away.

[KYCaster]

Only way to know is to get an xray analysis at a scrap yard. You could have anything in there!

BTW......I throw that garbage away!

bangerjim


+1 on what bangerjim said.
I removed the dross from my melt for a reason. I don't want to remove it again having put it BACK into my new alloy.
Why would I?


Hmmmm...........you paid for that stuff with your hard earned money or with your time and labor......probably both. Either way it cost you something......why would you throw it away?

It was in the alloy you purchased......if it's an undesirable element, why did you bring it home? Did you know it was an undesirable contaminant when you bought it? Did you have a plan to deal with the undesirable element when you agreed to buy it?

Most of the scrap lead available to us (wheel weights excluded) was alloyed to the original buyer's specifications, and with a little research and a lot of experience, you can make a pretty accurate estimate of the alloy content....generally various amounts of Pb, Sb and Sn, with trace amounts of various other metals which don't normally affect our boolits.

Unless you're intentionally trying to remove an undesirable element, there is no reason to throw away any metallic dross. After proper fluxing, a fluffy, gray residue should be the only thing floating on your melt. If there is any metallic substance in the dross you skim off your melt then you're throwing away valuable metal and you need to reevaluate your process.

Jerry

[bangerjim]

Nothing undesirable in there...............just the garbage you get from WW's and scrap when you melt it the 1st time to purify it. The only undesirable is the dross left over that I throw away.

And.........because I have tons of the PURE CLEAN alloy of all kinds and my time is far more valuable than trying to wring a drop or two of lousy lead/alloy out of that filthy carp. That's why I throw it away.

I am sure I have thrown away many pounds of "mystery metal" but I do not care at all. It is not worth my time to mess with it, as many on here will say also. If you are dead broke and have no lead and plenty of time on your hands................go after it! I, for one value, my time faaaaar more than re-melting a few pounds of garbage I skimmed.

banger

[bangerjim]

You can use the muriatic acid test. Take and scrape some off the ingot with a file and put a drop of muriatic acid on it. If it foams you may just want to throw it away.

It takes A LOT of Zn in an alloy mix to "foam". Small amounts of Zn in there will react very slightly. You may have to use a magnifying glass to see the reaction, depending on the % Zn. Pure Zn WILL bubble and foam violently, but no in small concentrations like you would normally see in our melts. The acid test is great for PURE ZN WW's, but not for small contaminations (I hope!) you would find.

banger

[prs]

If the dros was from alloy rendered from WW or mystery scrap, then I would (and have) toss(ed) the krap. But, this is from foundry metal, some clean lead sheeting from X-ray room construction and some pig lead which is again of foundry quality. There "should" not be any nasty undesirables, just oxidized good stuff that became trapped in the char of my vegetative flux and wax reduction agent. Given the large amount of casting alloy from which this was collected, it is very little indeed. I suspect it is tin rich as I prefer to cast hot'n somewhat frosty. Then again, even if it is pure tin, it would only be worth about $50.00, chump change, I suppose for some of you ;-)

prs

[prs]

I would add it back to wheel weight batches to bring up the hardness.

Unless the EPA (Egotistical Pompus Asses) reverses course, I think I am through with wheel weights. Too much non lead content for the effort.

prs

[bangerjim]

Not sure what you are calling "foundry quality lead" but there is NO tin in xray shielding sheets. I doubt if your dross has much Sn in it, other than the 0.5% from the WW's. If you are referring to linotype alloy, there is Sn and Sb in that alloy. I keep all my lino in it's virgin strip form and do not waste fuel melting it down into ingots, as it is very easy to weigh and is worth more in that form when selling. All the many many pounds of lino I have are bright and shiny and do not equire any fluxing or purifying.

Again, as said, I would personally not bother with the dross.

But that is totally up to you. I just finished hauling 280# of Sn home.....YES TIN.....and have pleanty of it.............forever.

There is no gurarantee of what is in that small quantity of render you derived out of the dross unless you have it analyzed by xray gun. Hardness means absolutely nothing. Zn can make it hard.

bangerjim

[1johnlb]

I always dump my dros can back in my smelting pot after a smelting session. I've already got my equipment out.I normally get about 2 # from 10# of dros. Then I add it back in on my cowboy or plinker boolits, the ones that don't matter anyway. I wouldn't clean it in my casting pot though. Call me a penny pincher,but thats my 2 cents.

[JonB_in_Glencoe]

I always dump my dros can back in my smelting pot after a smelting session. I've already got my equipment out.I normally get about 2 # from 10# of dros. Then I add it back in on my cowboy or plinker boolits, the ones that don't matter anyway. I wouldn't clean it in my casting pot though. Call me a penny pincher,but thats my 2 cents.

Yep me too !
I cast indoors with a small fan and open window, so I generally don't flux during casting. I always start with a good clean alloy and after I'm done casting, the pot is near empty, but I have some metal rich dross in the pot, it gets removed and put into soup cans...the last time I was smelting some range scrap (hand picked after a rain), I put the dross I had saved up. I think is was four heavy soup cans full. using lots of sawdust in the outdoor smelt yielded a very lightweight dusty dross to dispose of...and some beautiful ingots of range scrap that had been hardened some from that dross, as much of my casting is either COWW or 94-3-3.

I also agree with bangerjim, if my dross wasn't metal rich, I'd just toss it.

[cbrick]

prs, perhaps this thread will answer some questions for you, this used to be a sticky but seems it isn't any longer. Pity, valuable info in this thread that will now be lost.

This is a lengthy thread but if you go to post #30 and then post #115 you'll see XrF testing of ingots made from fluxing WW alloy with sawdust and an ingot then melted out of the used flux. Samples were cast from this ingot and sent for XrF testing.

http://castboolits.gunloads.com/showthread.php?213625-First-time-using-sawdust

Hope this helps.

EDIT to add . . . In post #115 see test #5 for the results of testing the samples from the used sawdust flux.

Rick

[JSnover]

Ok, I have a different question.
I render my dross when I have enough to fill a coffee can and I always get enough metal to make it worthwhile. But the remaining ash... What do you do with that? I would think it contains a fair amount of lead, arsenic, antimony, tin, or any combination of them. Not enough to melt it again but enough to make it toxic.

[RogerDat]

Ok, I have a different question.
I render my dross when I have enough to fill a coffee can and I always get enough metal to make it worthwhile. But the remaining ash... What do you do with that? I would think it contains a fair amount of lead, arsenic, antimony, tin, or any combination of them. Not enough to melt it again but enough to make it toxic.

Considering what is inside a landfill, and the requirements for monitoring and containing those landfill contaminants my vote goes for in the outside trash can so it can end up in the landfill. I'm sure it's nothing I want to bury in my own yard.

[1johnlb]

Return it to the scrapyard with the steel ww clips. That's what I plan on doing when I take a load of steel to the scrap yard. I have about a bucket and a half of miscellaneous scrap along with a old washer to go. Take it to the landfill and put it in the metal can, most have a scrap metal container. At least you can help keep it out of the water table, because it is toxic. If you put it in a trash bag it goes in most places, straight in the ground. If it's scrapped maybe they can get it refined or at least dispose of it correctly.

[Forgetful]

I used to dump the dross in with the clips after smelting but I've started saving the dross after I decided to try melting it in with a batch of weights to remove their clips. All the dross melted back in, I was quite surprised. I just don't know what the percentages are. This was the dross I removed after fluxing while I ladle pour mixed casting alloy into ingots. Definitely worth keeping. Seems like it's mostly tin. From now on I simply add the dross from the last batch to the bottom of my cold dutch oven pot, and pile lead on top of that and add calculated Sb and Sn based on the lead and not the dross. This way it's consistent. Each batch in this pot is about 40lbs, but I might be able to get 50 to fit in there.

Then when I'm casting boolits I'll mix my batches together, use the same number of ingots from each batch so they mix up well and get a more consistent alloy. Then flux. I'll keep the dross in there while I bottom-pour and flux it back in when I add more ingots. Seems to be working great so far.

Maybe its just me but I really enjoy smelting wheel weights because they seem to self-flux and so I never get dross.

[HangFireW8]

I did the same thing with much more dross, lower temps, a long cook and lots of sawdust. I got a few very hard ingots out of it that made it worthwhile. They alloyed and shot well.

I am finding that sorting through wheel weights is less and less productive as well.