# Refining silver



## danny987 (Jul 28, 2008)

I think i have the process down, but i want to check before i ruin my silver. 

1. Get nitric acid. (well this do? http://cgi.ebay.com/950-ml-of-Nitric-Acid-67-2-Purity-Disposable-Beaker_W0QQitemZ260267051924QQihZ016QQcategoryZ1267QQssPageNameZWDVWQQrdZ1QQcmdZViewItem)
2. dissolve Silver
3. Put copper in the solution. (how much?)
4. Silver sinks to the bottom
5. Dump the beaker through a coffee filter, and what is in the filter is pure silver.
6. Do i need to neutralize this?


----------



## goldsilverpro (Jul 28, 2008)

What type silver are you working with? Sterling? Why do you want to refine it? If it's just for fun - OK. If it's for profit, you're probably wasting time and money.

1 - The nitric on Ebay should work fine. The quart size being sold is enough to dissolve about 25 oz of silver or 7 oz of copper. The shipping costs almost doubles the price. Personally, I think $100/gallon, overall, is outlandish.

2 - Dilute the nitric with about an equal amount of distilled water before dissolving

3 - The more surface area of copper you have, the faster the silver will cement out. Try to find copper that is flat and clean. Uncoated buss bar is ideal. Wire is the worst, since the silver sticks in between the strands.

4 - Some silver will stick to the copper. Scrape it off. Test the solution with a drop of salt water to make sure all the silver is out. The presence of silver will produce a white cloud. 

5 - Rinse. Rinse. Rinse.

6 - Even with good rinsing, the silver will only end up about 99% pure. You will probably be money ahead by selling the silver without refining it, especially if it's something whose value is known, like sterling silver. When you supposedly refine it, the purity is unknown unless an assay is performed.


----------



## warrendya (Jul 28, 2008)

goldsilverpro said:


> Personally, I think $100/gallon, overall, is outlandish.



I noticed the seller gives a discount on additional items, so 4 bottles and shipping (to my zip code) came out to $83.93. Still seems ridiculously high but what other options are there? To make a gallon of poor mans nitric I'd need to spend $73.99 on sodium nitrate and shipping at cheap-chemicals.com, plus ~$5.00 on sulfuric obtained locally, and the final product would be less pure and less strong.

Is the only other option to buy a 100 gallon drum? The ebay seller may have hit onto a good idea - repackaging less than a liter as a consumer item. Since he's not paying hazmat, it's his shipping charges that are what's outrageous. I wonder if one of us who has access to large quantities could do the same.


----------



## goldsilverpro (Jul 28, 2008)

A 55 gal drum is the largest I've seen. The law states (at least, in Texas) that anything over 5 gallons must be packaged in stainless. As of about 4 years ago, the refundable drum deposit was $750 and the nitric ran a little over $2/gallon.

If you're near a city, call around. There may be a chemical company that will repackage in smaller quantities. In Houston, at Industrial Chemical & Scientific Co., I could buy in 1, 5, 13, or 55 gal. containers. The prices per gallon, respectively, were about $12, $10, $5, and $2 - 4 years ago.


----------



## danny987 (Jul 29, 2008)

If i had a mix of silver and gold could this work? 

1. dissolve both metals in sub-zero aqua rigia.
2. put in copper
3. filter out silver
4. put in sodium sulfite
5. filter out gold


could this work? This forum has helped so much.


----------



## meng2k7 (Jul 29, 2008)

danny987 said:


> If i had a mix of silver and gold could this work?
> 
> 1. dissolve both metals in sub-zero aqua rigia.
> 2. put in copper
> ...



hi!
yes it will work but your gold might be lessen,
maybe u should get the gold first before you take the silver.


----------



## danny987 (Jul 29, 2008)

meng2k7 said:


> danny987 said:
> 
> 
> > If i had a mix of silver and gold could this work?
> ...



Awesome. Not doubting you or trying to be rude, but if someone could second that i would feel more comfortable doing it.


----------



## Harold_V (Jul 29, 2008)

danny987 said:


> If i had a mix of silver and gold could this work?
> 
> 1. dissolve both metals in sub-zero aqua rigia.
> 2. put in copper
> ...


The best advice I can offer is for you to read Hoke. When you understand what she says, you will have the answer, but most importantly, you'll understand *why!*

Silver and gold, when alloyed, can be difficult to process, depending on the ratio of gold to silver. In general, too much silver and you can't dissolve the alloy with AR. Too little silver (or other base metals) and you can't break it down with nitric.

There are exceptions to what I've said, but they can be troublesome. It's best to understand the process of inquartation. Hoke will help with that. 

I am short of time, so I can't go farther, but Hoke will explain it in terms you will readily understand.

Harold


----------



## lazersteve (Jul 29, 2008)

I see a problem with the process listed above:

In step 1 the AR will form silver chloride which will need to be filtered out of the liquid. 

No silver should remain so step 2 is not necessary.

If the copper is used in step 2 it will precipitate the gold. This will result in the product being impure and require another refining.

In step 4 no gold will remain if copper is used in step 2 so sodium sulfite is not needed.

The process is wrong and needs to be revised to:

1. Dissolve scrap with AR.

2. Filter out Silver chloride

3. Convert silver chloride with dilute H2SO4 and Al, Fe, or Zn in a separate beaker.

3. Add sodium sulfite to pregnant solution and precipitate gold.

4. Filter out gold.

5. Wash gold

6. Repeat again

Steve


----------



## warrendya (Jul 29, 2008)

Boy, I hate to say it but after looking into it a bit I'm not so sure the ebay guy isn't doing the best he can. If he is really shipping legally, he has to have had documented and continuing training, use specialized shipping containers and packaging, and run the risk that DOT will decide his shipments are not suitable for personal household use (I checked that "consumer commodity" DOT designation and it allows the shipment of less than 1 liter of corrosives but it is fuzzy about what the allowable uses are).

I checked out his ebay store and he will sell a gallon of nitric (4 x 950 ml) for $53.99 with shipping to me for $16.87. I could not find any better price online in a half hour of searching, the next best price I could find was $99 for 2.5 liters, not including shipping.

It's just sad that hazmat and other restrictions have made this so hard. If anybody knows a better place to get it online, I'd appreciate knowing it. I'm in a pretty remote area so finding someplace local is not an option.


----------

