Zinc testing- with pictures

[evan price]

Here is a simple test if you have metal that you don't know if it is zinc, or contains zinc, or if it is a good lead alloy.
First, tap it. If it rings, it is not pure lead.

Here's another way with a simple chemical you may already have at your house, or store.


This is a simple toilet cleaner called "The Works". According to the MSDS-
http://www.instructables.com/files/o...F8GN4CZIND.pdf
-it contains between 15% and 25% hydrochloric acid by weight.

One of these two ingots is nearly pure zinc. The other is an ingot of smelted range lead.
Can you tell which one is which by looking?

Simply squirt some acid on both ingots and observe the reaction.



The lead ingot hardly foams at all.
The zinc ingot foams a lot. In fact it foamed so much the acid solution was pushed off of the ingot and onto the concrete before I could snap the picture. The yellow color of the foam is a reaction with the concrete surface beneath the ingots.

Be aware- the reaction between zinc or lead + hydrochloric acid produces zinc or lead chloride and hydrogen gas, which is very flammable! So no open flames near the testing, ok?

While Lead will produce a slight amount of fizzing (lead will react with HCl) Zinc is much more reactive.

Hope this helps!

[Patrick L]

Thanks Evan! That's good information to have.

[rmatchell]

I'll have to try this. I have a few ingots of unknown alloy from my first smelting.

[emmie]

could this be used to eat the zinc out of the lead?

[runfiverun]

no.
it's just a reaction.
you can pull a lot of zinc from an alloy with sulpher, temp control, and patience however.

[adrians]

I have a "cone" shaped piece of "lead" ( about 10 pounds) but i don't have that specific product.
Is there anything else lurking under my sink i could use to test this oddity?

[dRok]

Zinc should react with any strong acid if I remember correctly. Drain opener should work.

[abqcaster]

vinegar ought to work too. . .

[Freightman]

vinegar ought to work too. . .

It will!

[lwknight]

Zinc should react with any strong acid if I remember correctly. Drain opener should work.

Most drain openers are caustic not acid.

[Master Chief]

Great tip. Thanks. I'll have to pick a bottle of that stuff up.

[TheGrimReaper]

Great tip. Pics always are a help for me!!!

[Bored1]

I wonder if the "The works shower & tub cleaner" would work? 15-25% by weight of phosphoric acid per the MSDS sheet.

Thanks Evan, never even considered using google to find MSDS sheets before this!!! Will definately come in handy

[1874Sharps]

Any strong acid will work, but HCl (hydorchloric acid, or muraitic acid as the technical grade is called) is probably the best. Theoretically, HCl could be used to separate out zinc from an ingot, but it would not be the easiest or most economical way. Using good old stinky sulfur (and a respirator or gas mask if there is any chance of inhaling the fumes) is the standard and best overall method. The sulfur will bind faster with the zinc than it will lead or tin to form a metal sulfide. That is, kinetics favor ZnS formation. It is then easily mixed with a little flux and scraped off the top as dross.