# Steve, Where Art Though?



## nicknitro (Jun 9, 2009)

Steve,

I have been trying to refine some brazeing rod samples for my company, and have been going through a lot of nitric in the process. The process worked fine in small scale, however, as of late the refining is makeing a lot of copper nitrate, and very little silver metal to speak of. 

The base metal was 811 grams of 15% silver 5% phosphorous, 80% copper brazeing rods. I used approximately 3/4 gallon of 35% nitric acid to dissolve the metals with slight heat. I expect 3.9 oz of silver, but it is takeing too much acid to be realistic for any profit to me or my company. 

I should have listened to the montra of Harold, that dissolveing base metals to refine PM's will never be profitable, but alas.

My question is, what would you do, and please don't say sell them, as I would really like the extra income, and would hate to present that as the solution. 

Is AP a viable alternative to this high base metal material? Then converting the AgCl to silver oxide and further processing to Ag metal.

Sincerely,
Nick


P.S. You know this hurts just a little, as nitric is usually my acid of choice in Gold refining for removeing base metals. LOL


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## goldsilverpro (Jun 9, 2009)

> The base metal was 811 grams of 15% silver 5% phosphorous, 80% copper brazeing rods. I used approximately 3/4 gallon of 35% nitric acid to dissolve the metals with slight heat. I expect 3.9 oz of silver, but it is takeing too much acid to be realistic for any profit to me or my company.



To determine the best method, please answer these questions. How much of this material do you have? Is this a one-shot deal or is the supply of material ongoing? If ongoing, how much will you have per week?

Standard technical grade nitric acid is about 70% by weight. When you say "3/4 gal of 35% HNO3", do you mean 3/4 gal of 70% HNO3 diluted 50%? When I calculate the HNO3 needed for your 811 grams, I come up with 3/4 gal of 70%. In bulk, you can buy tech grade HNO3 for about $2-$5/gallon. That's not much. 

How are you getting the Ag out of the solution? Are you using copper bars to cement the Ag or, are you dropping it out as AgCl? When you say, "very little silver metal to speak of", do you mean that you're not getting what you expected? In both of these methods, you should get 100% of the Ag. If you don't get what is expected and, if you've done things right, the Ag wasn't 15% to start with.

If I had a lot of this material, I would try casting it into bars and then electrolytically dissolve and plate out the copper onto either a stainless or copper sheet (cathode). That way, there would be no nitric fumes or large amounts of waste copper solution. The electrolyte I would try first would be 160 gm/liter of CuSO4.5H2O and about 100ml-120ml/liter of sulfuric acid. The current density would be about 10-15 amps/square foot of cathode surface. The anodes would be inside of polyester bags. The Ag shouldn't dissolve and would be recovered as a sludge inside the bags. Each amp will produce about an ounce of copper in 24 hours. I have no idea what the 5% phosphorous would do in this system but I would guess it would end up with the silver.


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## leavemealone (Jun 9, 2009)

> you can buy tech grade HNO3 for about $2-$5/gallon


 
Hey chris are you sure thats correct?I buy it for around $50 a gallon,and I thought that was cheap.... :shock: 
If that is correct can you provide a dealer name or website?

Thanks,
Johnny


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## goldsilverpro (Jun 9, 2009)

I would try Univar first. They are everywhere. Also, look in the Yellow Pages under chemicals or industrial chemicals. You have to wade through these, because many only sell cleaning chemicals, Ag chemicals, etc. Try to find "technical grade" nitric. It sounds like you have been buying "reagent grade".
http://www.yellowpages.com/name/FL/univar

Individuals most probably can't buy from them. Companies can, but there are rules. Call them for the rules. Different states have different rules. In bulk, stainless steel containers are required by law for nitric acid. The deposit on a SS 55 gal drum was $750, 4 or 5 years ago. The deposit on a SS 15 gal carboy is less. Of course, you get the deposit back when you return it. If you are close enough, many companies will deliver and pick up the empty drums.

Also, a few companies repackage industrial grade chemicals in smaller quantities. Usually, these are companies that also sell lab supplies, mainly to hobbyists. Three or four years ago, in Houston, a company was selling re-packaged nitric in 1 gallon containers for $12.


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## leavemealone (Jun 9, 2009)

Thanks chris,I'll do that this afternoon when I get home.It would be nice to have some nitric again.
Thanks again,
Johnny


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## nicknitro (Jun 10, 2009)

Chris, 

Hello again. First to answer your questions.

The test sample was one secured from my company, after I presented the Idea to our VP. The amount of ongoing material supply would most likely vary due to chaotic variables in the amount of business we are experienceing. I would estimate approximately 2500 grams a month.

The solution of nitric acid I have procured is a 35% diluted solution. I have no business license as of yet, and would find it a real hassle to order the technical grade 70% nitric acid. If I need something stronger, should I try some poorman's Nitric? 

As for getting the silver out of solution, I was under the impression that the 80% copper would cement the silver out as Ag metal. I have teted the solution so far with HCL and have not produced any noticeable precipitate.


I like your idea for electrolysis. It seems to be the way to go, however I haven't seen a lot of info on the forum about setting up a silver cell. Could you recommend a good post on the subject? What would you consider to be a lot of this material to be?

Thanks GSP,

Nick


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## Harold_V (Jun 10, 2009)

nicknitro said:


> As for getting the silver out of solution, I was under the impression that the 80% copper would cement the silver out as Ag metal.


Pardon my jumping in here-----it should work, but if it doesn't, it's entirely likely that a parting cell won't work, either. 



> I have teted the solution so far with HCL and have not produced any noticeable precipitate.


Are you saying that you have tested some of the solution that resulted from dissoving some of the material, and found you had no silver chloride precipitate? 

If that be the case, it's possible that the remaining copper is cementing down the silver, just as I suggested it would. Look for some dull silvery powder in the bottom----which should be the cemented silver. 



> I like your idea for electrolysis. It seems to be the way to go, however I haven't seen a lot of info on the forum about setting up a silver cell.


Nope----this won't be a silver cell. There's no way in hell you would have success parting such a low grade silver, and you may not have much luck parting such low grade copper. Parting cells like relatively high quality feed, otherwise the contaminants change the nature of the operation quickly and they fail to deliver. That's the problem with trying to recover copper from spent solutions electrolytically. It doesn't plate out hard, it tends to come off as sludge---which is of little value without melting. You're right back where you started, with dirty copper that has no market. 

Chris has a lot more experience than I have where it comes to the plating of metals. He may damned well correct some of the things I've stated. Both of us will learn something from him. 

Harold


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## nicknitro (Jun 10, 2009)

Harold,

Glad to hear from ya. I think you had better send Johnny some pics of your house before he comes up there. LOL

I was saying tested, sorry typo, it happens now and then as my computer gets slower. Harold, do you know of a good post that I could read up on for createing a silver cell? I reallize you have said that it is not a viable option for the materials I am refining, but it may be of some help when I decide to further refine. 

As for the cementing process, I know can see a dull gray precipitant forming on the undissolved rods. 

Most likely from leaving the heat on too long, as it is kinda stuck to the rods. I guess another nitric addition is in order.

Still no response as to wether AP would be a cheaper process with maybe an aerator.

Thanks all,
Nick


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## goldsilverpro (Jun 10, 2009)

nicknitro,

I guess I was confused. I thought you were totally dissolving the solder in nitric. If so, there would be no copper left to continually cement the silver. All the silver would be in solution and you could easily collect all of it. 

By only partially dissolving the alloy, I don't see what you have gained. It sounds like you now have a mix of undissolved solder that still contains silver and cemented silver, with no silver in solution. If you're going to use nitric, I would dissolve everything.

Harold is right. A silver cell won't help at all, unless you want to purify the silver that you've collected by cementation or other means. To use a silver cell, the break even point is to start with about 90% silver. Below that purity is a waste of time.

What I suggested was a copper cell.


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## Harold_V (Jun 10, 2009)

Nick,
Oz has been running a silver cell for a while now, so maybe he'd like to share some of his thoughts. There are so many variables where a silver cell is concerned that it might be a waste of time trying to make specific recommendations, or guidelines. They are actually a very simple device. You can make one from something as simple as a stainless pot from a steam table, or you can get heavily involved and make one to a specified design. 

Right now, concentrate on recovering the silver--which is obviously cementing on the remaining copper. Remember, it's alloyed by weight, so copper being much lighter than silver, don't expect much volume. 

Before you can operate a silver cell, you'll have to recover enough silver to make not only the anode, but the electrolyte. Depending on the size of the silver cell, that could be many ounces, or just a few. My cell required 30 ounces for electrolyte, and the anodes weighed in at random 150/200 ounces. That was a small cell, by the way. 

Butts & Coxe authored a good book on silver----one you may enjoy reading. In it there are descriptions of silver cells and parameters within which they operate. Sorry, I don't have the title at my disposal, and my copy is buried in storage. GSP will know of the book, so maybe he can provide the title. 

Harold


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## Anonymous (Jun 10, 2009)

Harold_V said:


> Butts & Coxe authored a good book on silver----one you may enjoy reading. In it there are descriptions of silver cells and parameters within which they operate. Sorry, I don't have the title at my disposal, and my copy is buried in storage. GSP will know of the book, so maybe he can provide the title.
> 
> Harold



I have the book the tittle is " SILVER Economics, Metallurgy and Use by Butts & Coxe". ISBN: 0882752782 

To bad it has not been scanned.


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## goldsilverpro (Jun 10, 2009)

Great book. Probably the best silver book written. I use it all the time. I used it today for something. It's 42 years old but there are very little changes in precious metals.


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## metatp (Jun 10, 2009)

Sounds like I should get my hands on this book. Any idea of where I can get it?

Thanks,
Tom


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## nicknitro (Jun 11, 2009)

Thanks All,

Harold, now see why the silver cell was reported to be very cdostly to set up for a small scale operation. 

Another question, If I were to do this type of refining, would it be advised to just buy the scrap, and not try to commision it out? Perhaps saving the materials for inevitable inquartaion in other refinings? Seems to be an expensive process for an inexpensive metal.

Chris I am not quite sure as to what you are getting at? The reason I have not been adding all th nitric at once was to avoid foam-overs. I have been adding the nitric slowly in about 2 cup intervals with minute amounts of water, as it is already diluted. I wait for the reaction to subside then I use heat to use up the rest of the nitric in solution. I expect most of the silver to be cemented out from just the copper in the brazing rods alone, but I also have some copper buss bar to cement out the rest when my dissolution is complete.

I believe my real issue is that the nitric I have purchased is just not strong enough, for the cost of purchaseing it. The 70% technical grade I have seen in Steve's videos produces a much more violent reaction, and far more NO2 fumes. Maybe this is a good thing? LOL The reaction is coming along slowly, and some silver is precipitating. I think I will have to further process it though, as I used some tap water for washing instead of distilled. It can't hurt to conver to AgCl, right? Then to silver oxide. What happens when AgCl contaminates Ag metal? Does it just make the melting process hazardous from the fumes?

Thanks again,

Nick


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## Oz (Jun 11, 2009)

Nick,

The best rule in refining is to try to avoid buying anything. If you buy it even at fair value you are subject to the price fluctuations of the market for the period of time it takes you to process it. Oldtimers like GSP and Harold will tell you that we are in unprecedented times as to spot price volatility. If you take material in promising X percentage in cash as payout of recovered precious metal or as returned .999 fine and you make settlement based on the spot price the day you have finished refining, this allows you to eliminate all price volatility until you can lock in a sale to someone else.

As to the concentration of your nitric it is more a question of your priorities, cost of acid or time. Higher nitric concentrations are faster, but 35% concentrations give you increased efficiency of your acid as some of your NO2 can be reabsorbed by your solution to do work again as nitric, it depends on your priorities. You mention cost of nitric, you are correct in looking at the cost vs. concentration, do the math on your sources thinking about what I said above.

Tap water? Probably the worst thing you could ever do to any refining operation involving silver is to add chlorides. Distilled water is inexpensive in most grocery stores. I live in a humid climate so I get mine as a byproduct of my dehumidifier.


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## Harold_V (Jun 11, 2009)

nicknitro said:


> Another question, If I were to do this type of refining, would it be advised to just buy the scrap, and not try to commision it out?


I am likely not the right person to ask. I had a strict policy where precious metals were concerned. I got them cheap, or I walked. For years, I purchased 1/10-12KGF eyeglass frames for as little as 10¢/pair, but never more than 25¢/pair. I accumulated a large amount of gold that way, having started buying when no one but me had an interest. Remember, I got started refining in the early 70's. 

Another great buy was when I purchased two ounces of placer gold while on a trip to California. Had to pay $60 for it, though!  (Gold was about $100/ounce at the time).

I also recall buying a set of sterling flatware, service for 12, for $200. In all cases, I never set the price-----I paid what was asked. 



> Perhaps saving the materials for inevitable inquartation in other refinings? Seems to be an expensive process for an inexpensive metal.


If I was in the position where I had to process the stuff, that's exactly what I'd do with it----use if for inquartation, and I'd probably use it along with silver. 

Frankly, if you have an ongoing supply, it would probably be wise to accumulate the stuff and sell it in a large lot to one of the major refiners. I'd see it totally differently if you could buy nitric for the price I used to pay ($207 for 55 gallons of tech grade, 70%).

As far as tap water is concerned, my personal experiences dictate that it makes little difference, as long as you don't discard anything. If, when you melt recovered silver that has been exposed to chlorine, a small amount of soda ash is included, the small amount of silver chloride that is present will be reduced. When I dissolved silver in inquartation, I routinely used tap water, and it was heavily chlorinated. Enough you could smell it. For me, it was far more convenient to deal with the traces of silver chloride than to deal with distilling the water-----and I owned my own still. 

I fully expect that no one will agree with me on this issue. It is a report on what I did for years, so I know it works. 

Harold


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## nicknitro (Jun 11, 2009)

Thanks Harold and OZ,


Though you have two conflicting points on the tap water issue. Like I said, if it is that big of an issue, I suppose I could just convert it all to AgCl. Not much cost involved, 'just a little more labor.

Oz,

Even at the conveiniance of purchasing this 35% nitric solution, the cost is harsh approximately 14 dollars a gallon. A tear jerker compared to the price of Harold's $207 for 55 gallons, even if he had to pay 800 or so for the stainless drum. 

What is the concentration of regular poorman's nitric? Assumeing I used 98% sulphuric and sodium nitrate?

Thanks all, and I don't think I've had much experience with you Oz, so thank you,

Nick


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## goldsilverpro (Jun 11, 2009)

HTPatch,

Here's some excellent used prices for the Silver book by Butts and Coxe
http://www.bookfinder.com/search/?author=butts+coxe&title=silver&lang=en&isbn=0882752782+&submit=Begin+search&new_used=*&destination=us&currency=USD&mode=basic&st=sr&ac=qr


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## metatp (Jun 11, 2009)

Thanks again!


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## Oz (Jun 11, 2009)

I completely understand Harold’s point of view on silver chloride. The difference is he did not mind dealing with it and I greatly dislike the added hassle. 

Laser Steve has written some very detailed information on poor mans nitric with yield and concentration data. Given the cost of nitric in your area and the volume of material you will run if you do this “in house” I would think it might be worthwhile to set up for distilling nitric from sulfuric and sodium nitrate. Do not forget to place a value on your time, add up the material costs for making your own nitric and compare it to the cost of your 35% nitric. Is the price difference worth the hours in labor you would spend in saving the money? Each individual will have a different answer to that.

Remember that your feedstock in this case is 80% copper. It takes roughly 3 times the amount of nitric to dissolve a gram of copper than it does a gram of silver. I have never dealt with material that contains phosphorus with nitric so I do not know how to account for it in nitric consumption. Having said that if I take a kilo of your material containing 150 grams of silver and 800 grams of copper I would expect it to take 6.833 liters of your 35% nitric (35% nitric is equivalent to 50/50 70% nitric/water) to put them both completely into solution. 

You are paying $14 a gallon for 35% nitric or $3.70 per liter, so needing 6.833 liters X $3.70 = $25.30 per kilo of material or 150 grams of silver for a cost of $0.17 per gram. At this moment silver is $0.49 a gram on the comex giving you a $0.32 gain or $48.00 per kilo of raw material if sold at current spot, minus of course you raw material cost and labor. There are of course gains that can be made on this as once you have a batch in solution you can cement as much as possible with additional rods giving you some free processing of material and cemented values. You could also just send it to me ;-)

I encourage Harold and/or GSP to check my numbers and I would love to hear their input on the phosphorus as I am clueless as to its roll in this.

I hope that helped instead of confusing the issue.


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## 4metals (Jun 11, 2009)

I was asked by a client to advise him of the chemical cost to refine 1 ounce of karat gold, including waste treatment chemicals, I needed to get all of his chemical costs and when I did the math it came to $.27 per ounce digested. The cost of the nitric was $4.18/gal purchased in 55 gallon drums. (which carry a $650 deposit!) So there are better deals out there than $50/gallon for nitric.


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## leavemealone (Jun 11, 2009)

No offense but I would NEVER disclose to a client or potential client what my expenses are.All they will see is how much they are paying you to do the work,they will never understand the processing side of it.All of the days running this acid and that acid,all the filtering and rinsing and dont forget firing up the torches.And as if all thats not enough,you cannot put a price on your experience.
Johnny


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## Oz (Jun 11, 2009)

Johnny, 4metals is a consultant so it is his job to teach people how to refine for a fee, selling knowledge instead of gold. Fortunately he has chosen to share some of that here for free.


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## leavemealone (Jun 11, 2009)

AHHHHH I guess you can teach an old dog new tricks.Something I never knew....lol.Thanks oz. 

Sorry bud,you know I only had the best intentions.
Johnny


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## nicknitro (Jun 12, 2009)

Hello All,

First off, Thank you for your time guys.

Oz, an excellent post, that really helps put the cost into perspective. I really enjoyed reading your post. I will look into Steve's site concerning the percentage of nitric-like acid in poorman's nitric. 

A distiller has been mentioned as a suggestion before by Chris. However, I currently don't have the right setup to deal with the distilling process or the fumes. 

As for sending them to you, I don't know if that would be an option. Sorry, involving shipping to a low margin base material would probably kill any profit potential. May I ask what you use them for? I see many people say they would prefer them for brazing purposes. I have seen them on Ebay for about $35 dollars a pound. Approximately 28 sticks. This should be more than enough for average home owner use. No?

Thanks again,

Nick


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