Help with zinc

[gunsbrad]

I have zinc contamination in approx 4-500lb of ingots.

I have followed the threads here and did the muriatic acid test. I want to remove the zinc with sulfur. I have to drive a ways to get it. What I need to know is approximately how much to get. Also as I have never done this before I will accept any advice I can get on the actual working the zinc out.

Thanks,
Brad Hurt

[lwknight]

In my case , a local scrapyard buys lead for 60 cents and sells it for 75 cents.
So I would just sell , buy and trade for pure lead.

[gunsbrad]

no such luck here.

I'll have to try to reclaim this stuff

Brad

[sagacious]

What symptoms of 'zinc poisioning' does your lead have?

What were the results of the acid test?

[gunsbrad]

Acid test was positive.

Symptoms: oatmeal, hard to cast good boolits, etc.

Brad

[hammerhead357]

Check out the third sticky from the top about using sulfur to flux it out. Might work I have never had to try it but I think it would be worth a shot....Wes

[docone31]

I just finished loading up 200rds of zinc 200gn castings for my ACP. I blend the zinc into my melt.
I find, it makes a good firing casting. No leading, no jams, no residue. Very little wear if any showing.
You gotta keep the heat on casting though. Only drawback.

[sagacious]

I have zinc contamination in approx 4-500lb of ingots.
I want to remove the zinc with sulfur. I have to drive a ways to get it. What I need to know is approximately how much to get.
Brad,
Here's an estimation. If 2% of your 500lbs of alloy is zinc, and you can remove all of that as zinc sulfide (ZnS), then chemically you need a minimum of 5lbs sulfur.

Realistically, and accounting for waste, etc, the amount of sulfur required is probably doubled, and the amount of zinc removed is not likely to be anywhere near 100%.

Were I in your position, I would do everything within my power to avoid having to flux 500lbs of lead with sulfur. Good luck, and be careful.

[docone31]

If you really want to flux with sulpher,
Try taking small amounts, hammering it out as thin as you can, then pouring Rooto Drain cleaner on the metal in a plastic pan.
Should do almost the same thing. Rooto is sulpher based, I use it in processing gold, so it should attack the zinc. When it stops bubbling, go to the next piece of metal. When it is done, melt it into ingots.
With the metal hammered thin, the acid should attack from all sides. If you can warm it up, it works faster.

[gunsbrad]

sagacious

Thanks for the advice. I do not want to sulfur 500lbs of metal but I don't see another alternative. I don't want to lose this much bullet metal at todays prices. This sounds like the best option as this stuff is unusable now.

docone31 That sounds like an idea, but I really don't want to hammer 500lbs of 1lb and 1/2lb ingots flat. I may think about that some more.

Thanks
Brad

[gunsbrad]

I found 10 lbs of sulfur today. I will try it in the next few days.

Just in case it didn't work I called the scrap yard. They will pay me $.05 per lb for my clean ingots. That's 5cents. Can you believe that.

Brad Hurt

[sagacious]

sagacious

Thanks for the advice. I do not want to sulfur 500lbs of metal but I don't see another alternative. I don't want to lose this much bullet metal at todays prices. This sounds like the best option as this stuff is unusable now.

Thanks
Brad
Here's an alternative process that may improve your situation, if you can get ahold of known pure lead.

This would be easier to do in large batches, but work with the equipment you've got. Fill your melt pot 1/2 full with your zinc-poisoned lead. Heat to just above the melting point, but not much hotter. Skim off as much of the floating slush as possible, and set it aside for later treatment. Stir the melt and let it sit for 5 minutes. Skim again.

Then add a few ingots of pure lead. If needed, increase the temp enough to melt the lead. Add enough pure lead (NOT ww lead) to exactly equal the amount of Zn-poisoned lead in the pot. When it is all melted, flux very generously with paraffin or beeswax. Skim off the dross and add it to your previous skimmings.

Now go through your normal pouring routine-- you may have to keep the melt hotter than normal-- and tell me what the results are. This should have a noticeable positive effect on the fluidity and fillout of your alloy.

The amount of skimmings will be minimal as compared with 500lbs. I would suggest that you try fluxing the skimmings with sulfur at a fairly low temp first, not high temp. Once treated, flux again with wax and blend the resulting alloy into your melt gradually.

Best of luck.

[gunsbrad]

Sagacious,

That is an interesting proposition. Could you be more specific about fairly low temp, or high temp, and why?

Thanks
Brad

[sagacious]

See my reply on your Zinc #2 thread and we'll hash it out there.