Sciencemadness Discussion Board

Source of Zinc found

vmelkon - 1-5-2019 at 10:29

I collected a few of the spark wheels from lighters (the butane kind, disposable lighters).
Like this one.
https://en.wikipedia.org/wiki/Lighter#/media/File:White_ligh...

I think the spark wheel is partially made of zinc.
I was able to melt it easily. It is clearly not aluminium.

Felab - 1-5-2019 at 10:57

I usually get mine from Zn-C batteries. I think it's a lot cheaper.

MrHomeScientist - 1-5-2019 at 14:13

My preferred source is boat anodes from West Marine. They come in all shapes and sizes, so you can get whatever amount you need!

RedDwarf - 1-5-2019 at 14:17

Zinc flashing for roofs (NOT zinc flashing from roofs!)

Sulaiman - 1-5-2019 at 15:05

6V lantern batteries have four pure zinc cups of about 18g each.
(the zinc must be very pure to prevent premature internal corrosion)
You also get MnO2 with carbon paste, and four carbon rods,
and a great big mess - but you gotta do it at least once.

via eBay I can get 99.9% zinc with p&p, 100g for £5 or 1kg for £22.

I suspect that most ex-product sources of zinc will be alloys of zinc,
for manufacturing ease, castability, durability etc.

Morgan - 1-5-2019 at 15:30

I bought a zinc sacrificial anode for a boat that was shaped like giant washer, the two halves held together by two screws, about 20 centimeters in diameter and 5 centimeters thick.

As an aside, this trend on zinc anodes for boats ....

Not zinc
"In recent years cadmium in zinc has become an environmental concern, leading to a movement in the direction of aluminum anodes. Such anodes are effective even for protecting aluminum components — lower end cases, for example — because the aluminum used in the anode is a more anodic alloy. Aluminum alloy anodes are almost certainly to become more common. It has not happened already only because the cost of aluminum anodes has been higher than zinc without any discernable benefit to the boatowner. Today aluminum is actually cheaper than zinc. In addition, aluminum anodes tend to last longer, they work better than zinc in brackish water (and maybe in salt water as well) and they appear to be better for the environment. When making the switch from zinc to aluminum, ALL of your anodes must be aluminum. This can be a problem in some locales as many local marine suppliers still do not stock a wide selection of aluminum anodes. That will eventually change."

"In fresh water, magnesium anodes protect underwater metals better, particularly underwater aluminum. However, magnesium is a good choice for freshwater only. If any of your boating is also in brackish or salt water, fit aluminum anodes."
http://www.boatus.com/boattech/casey/sacrificial-zincs.asp

fusso - 1-5-2019 at 15:58

Quote: Originally posted by Morgan  
In recent years cadmium in zinc has become an environmental concern, leading to a movement in the direction of aluminum anodes.
How much Cd is in the Zn anodes? Is it worth to extract the Cd?

Sulaiman - 2-5-2019 at 02:57

Quote: Originally posted by fusso  
Is it worth to extract the Cd?


If you are desperate for cadmium and zinc is your only source, then YES.
other scrap sources are probably more productive,
but cadmium wet chemistry is as atractive as lead chemistry ... waste handling.
or you can get 9oz. 99.95% cadmium via eBay USA for <£10
===============================================
I have enjoyed recovering gold from scrap,
and the zinc cans, carbon rods and manganese dioxide from a lantern battery have all been useful for various chemistry experiments,
but
because I am lazy, and can afford it, I like to buy small samples of pure metals, (and non-metals)
this allows me to make known 'pure' reagents/reactants when required.
100g samples from China usually cost around £5 with p&p to UK,
even though I have not really used about half of my metal samples,
they have a long shelf-life and are always available for use, or just to look at, or examine.
Small additions to a kind of working element collection.

Morgan - 2-5-2019 at 08:11

I don't think the cadmium level in zinc anodes is anything but modest, probably approaching 1% at best from what I read but perhaps hundreds of boats docked at a marina for example makes it of concern?

As an aside ...
If you like twists and turns of electrochemistry/street smarts, there's these delightful ifs, ands, or buts, on deciding which sacrificial anode to use on boats for different occasions and things that can go wrong in certain scenarios. Interestingly one method, they add gallium and zinc to aluminum anodes to block the protective oxide layer pure aluminum forms.
https://www.boatingmag.com/how-to/choosing-right-sacrificial...

This is one of the more unusual sacrifishal anodes out there.
https://www.westmarine.com/buy/martyr--clamp-on-grouper-anod...

[Edited on 2-5-2019 by Morgan]

RogueRose - 2-5-2019 at 15:13

If cadmium is worth recovering, I'd give it a shot as I have about as much as I can handle in the form of NICd batteries. It would probably be a lot easier to process it if the batteries could be shredded or chopped up somewhat then try to dissolve the Cd and Ni w/o too much Fe (which might be stainless I think) being dissolved into the solution. Then maybe electroplate it out of the acid solution? That should give some pretty pure Cd.

For those wondering where to find these, you can usually find old batteries for free, sometimes by the bucket load or cooler full (I saw a 32 gallon cooler full of old dead NiCd 18V batteries from a building/housing contractor). Another source might be some junk yards b/c I think some very early hybrids used them as teir battery pack, then they went to NiMH then Lithium.

zed - 2-5-2019 at 16:12

Zinc?


Current U.S. Pennies are 97.5% Zinc. Copper plated Zinc, they are.

vmelkon - 3-5-2019 at 11:47

Quote: Originally posted by zed  
Zinc?


Current U.S. Pennies are 97.5% Zinc. Copper plated Zinc, they are.


I collected a lot of those pennies since some come into the USA but pennies have been eliminated in Canada for a few years now.

I haven't seen any other sources of zinc in Canada.
The lighters that I mentioned can be found in the streets, on the grounds, in the parks. They are free.

Morgan - 3-5-2019 at 15:23

What about those zinc die cast conduit fittings/EMT fittings, you can buy a small bag of them for cheap in the U.S.? Not nearly as cheap as pennies but a source if desperate. Don't know if they are pure zInc though.

The little set screw and sometimes the nut are steel or something magnetic something like this particular 5 pack. Some come with a zinc nut, I think I've seen both that is.
https://www.homedepot.com/p/Halex-3-4-in-Electrical-Metallic...

https://www.homedepot.com/p/Halex-3-4-in-Electrical-Metallic...


[Edited on 4-5-2019 by Morgan]

egret - 4-5-2019 at 13:34

The zinc sheets for roofing can be a source of zinc.