Zinc in an alloy

[Charlie Sometimes]

Saw a show named something like "How they do it" the other evening. They were plating hotel door card-type lock covers with zinc to resist weathering. They stated that the zinc ingots melted at 735 degrees Farenheit.

This caused me to think about casting boolits (everything causes that, it seems) and the low temps involved or suggested by various individuals to remove the zinc using a low casting temp and lots of skimming. :evil:

I don't see that it is at all possible- the utectic point of a lead/tin/antimony alloy is about 450 (IIRC), usually adding anything to make an alloy changes the melting temp of that combo lower than the individual melting points of the separate elements, right? So wouldn't the zinc in an alloy of lead/tin/antimony be nearly imposible to remove? :veryconfu

I think I have some alloy that is contaminated with zinc, but I really haven't worried about it much. I mix it with other metal and effects are negligable, if noticable at all. Except it may contribute to hardness, and now because of that show, I know they will be weather-proof! :groner:

Just my view from the back porch. [smilie=s:

[runfiverun]

zinc does add hardness to lead.
what you are doing when removing it is holding the alloy at the sludge stag for the zinc.
and scraping as much out as you can antimony will ball up in a cold alloy too.
my old lee pot only got up to 630* and i would have a bunch of mush on top of the alloy for a period of time but it would become soluble again after about 10 more minutes of heating.
only about 2% is soluble in lead alloys.[airc]
they also use zinc to remove tin from alloys in the foundry's but at a very high temp[1250 or so if i remember right] and then they move the lead alloy along and shoot the zinc through it.

[docone31]

You can seperate an alloy with acids. Dropping out individual metals recquires a drop out agent.
I suspect, zinc will alloy up to a point. I have read 2%. After that, the zinc will be a colloid. That is where reduction of heat so just the lead/alloy is liquid. In that regard, zinc will slowly float to the surface leaving the resultant alloy behind.
In the case of gold, it is rendered with nitric acid. The gold goes into solution. It is dropped out with SO2. The other metals remain in the solution. To get the remainder of the metals out of the acid, Urea will neutralize the acid, copper will drop out, after that, the remainder of the metals in the alloy will drop out with sodium metabisulphate. The pure silver can then be brought to bear with Karo Corn syrup.
I am sure, lead and lead alloys are the same with different chemicals.

[Charlie Sometimes]

WOW. I've never been much on chemistry, except where bullet casting is physically involved. I always wondered "how they did that",and now I know. Thanks, docone31!

The low heat method, though, would cause you to loose a lot of the "good stuff", too. That was my point. Everytime you flux, it just puts everything back together, until it separates again. I must have my batch down to near the 2% mark, as there is very little "floaters" requiring skimming.

[snaggdit]

You can seperate an alloy with acids. Dropping out individual metals recquires a drop out agent.
I suspect, zinc will alloy up to a point. I have read 2%. After that, the zinc will be a colloid. That is where reduction of heat so just the lead/alloy is liquid. In that regard, zinc will slowly float to the surface leaving the resultant alloy behind.
In the case of gold, it is rendered with nitric acid. The gold goes into solution. It is dropped out with SO2. The other metals remain in the solution. To get the remainder of the metals out of the acid, Urea will neutralize the acid, copper will drop out, after that, the remainder of the metals in the alloy will drop out with sodium metabisulphate. The pure silver can then be brought to bear with Karo Corn syrup.
I am sure, lead and lead alloys are the same with different chemicals.

I always wondered... We are talking powdered metal dissolved into a solution? I would think dissolving plate gold alloy in nitric acid (except maybe regent grade) would take a while.

[Charlie Sometimes]

Was reading my 3rd edition of Lyman Cast Bullet Handbook yesterday- lots of tables and other info in there about Pb/Sn/Sb alloys and other "contaminates". I had forgotten all about the information that is listed! (NOTE TO SELF: Reread all reference material periodically!) Other ideas are now floating through my brain housing group- uh-oh.

[docone31]

Actually, dissolving gold in acid does not take that much time.
With nitric acid, everything dissolves. SO2 gas is bubbled into the mix to drop out the pure gold. Gold is not completely pure in nature, 22KT is as far as it goes. With acids, or electrolysis, you get 24KT.
You have acid, and then there is the salt technique.
With the salt technique, gold is melted into a button. It will have the alloy materials, the gold and other such stuff.
I use a stainless steel pan for this, I make a solution of salt. Softener salt works well. I attach a stainless steel wire to the button, take the anode from a battery charger, clip it to the button. The cathode goes to the stainless steel bucket. In the bucket, I put a flower pot. The brown one without an hole in the bottom. That is important!
The electrolysis dissolves all the metal except the stainless steel wire and bucket. The ions of the metals, except the karat gold pass through the pot. The karat gold stays in the pot. The salt solution allows the current to pass from the anode to the cathode. Any gems, will fall to the bottom of the pot also.
That gold, in the pot, you simply scoop up and melt into a button. That is 24KT gold.
That process takes a while, but, no fumes or dangerous chemicals. A good thing. The alloy metals are in the salt solution. If, for whatever reason, you want to drop them out, you remove the pot with the gold in it and add sodium metabisulphate. All the metals fall out into the bottom of the stainless steel pot.
To seperate plating, muriatic acid and chlorox bleach. The alloyed gold falls off. Another technique is to use a battery charger, Drain cleaner, and a lead anode. Make a lead anode, place it into the Drain Cleaner, I prefer Rooto, it is more pure. Clip the material to be seperated to the cathode. Set the item in the drain cleaner and turn on the charger. The piece will fizzle, and black muck will settle on the bottom of the glass pan.
That is your gold.
A lot of work, but it can be done.

[Beekeeper]

And here I thought we only talked about boolits.
I'm impressed I have learned something that I always thought was an arcane science
This was one very interesting post.
Thanks


beekeeper

[runfiverun]

you can also separate gold with mercury it will cling to it.
then you hollow out a potatoe, place the mercury solution in side the hollow, and burn the potatoe in a fire like you are baking it. the potatoe will absorb the mercury and leave the gold it will also keep the fumes from the mercury from escaping.
then you can do the electrolysis in the bucket trick.

[Leadforbrains]

Man this place is better than the Discovery channel!

[Beekeeper]

I agree LFB.If you look around on this site there is more info than the learning channel ever had.

Docone31,
Where did you learn about all the chemicals to seperate metals.
Now don't say high school science.all they taught me was girls were different.

beekeeper

[docone31]

A long time ago, I ran with Geeks.
Then I discovered the Hoke Book.
A true how it works. It has been out of print for 50yrs.
It is old school.