Metals from picture fixer solutions?

Ok – I tried a forum search using “picture fixer solutions” & got a no match

I picked up 2 containers of this stuff today from a guy that used to have a 1 hour photo shop & his photo developing machine would recover the metals from the fixer solutions.

One container is 7 lb of the black lump on the left that looks like charcoal & crumbles real easy & melts to the metal in the center

I put this piece of metal in a shot glass with nitric diluted 50/50 & no visible reaction after 5 minutes – so took it out, washed it off & tried HCL – again no visible reaction after 5 minutes – took it out & washed it off & tried AR & again no visible reaction after 5 minutes. This was all done at room temp

The fixer solutions this stuff was recovered from was primarily color pic solutions “some” black & white. I believe chrome was used in color fixers & he mentioned nickel. Also on page 87 of Hokes, she says – “several other metals (besides Ag) including Au, Pt, Fe, Pd, U, & Se find employment in photography, printing paper, & toner solutions. She talks about several ways of recovering the metals from solutions – but I already have the recovered metals – If I had the solutions I could test with stannous & figure out how to approach recovery – so my problem is how to get it back into solution for testing & recovery.

I have 7 lb of the black charcoal like stuff (on the left) & 7 ½ lb of the metal chunk on the right (I haven’t run any test on the chunk to the right yet)

At this point I am thinking I need to inquart with ether copper or silver – then go with nitric – then AR – but thought I would throw it out here to see what the rest of you could suggest.

Kurt

kurt said:

One container is 7 lb of the black lump on the left that looks like charcoal & crumbles real easy & melts to the metal in the center

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You most likely should be melting that material with soda ash and borax, including some scrap steel. Otherwise you may be losing some of the values as sulfides.

I put this piece of metal in a shot glass with nitric diluted 50/50 & no visible reaction after 5 minutes – so took it out, washed it off & tried HCL – again no visible reaction after 5 minutes – took it out & washed it off & tried AR & again no visible reaction after 5 minutes. This was all done at room temp

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It should be silver. Conducting tests without using heat can be a mistake, so don't take the results as being of value.

HCl and AR are the wrong test. Remember, you're supposed to be looking for silver, which doesn't dissolve in either of them.

Can you say Schwerter's solution? There's nothing like it for a fast test for silver.

Go back to the sample you produced, and place it in a beaker with a few drops of nitric, along with a few drops of water. Heat the material. Silver should dissolve readily. If it does not, I have no clue what you have.

At this point I am thinking I need to inquart with ether copper or silver – then go with nitric – then AR – but thought I would throw it out here to see what the rest of you could suggest.

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Do you understand why one inquarts? If not, review what Hoke says about the process. Mean time, unless you have reason to suspect there's gold in the metal (color is clearly wrong, plus it makes no sense that you'd recover gold from the source mentioned), inquartation isn't even remotely called for. You simply have to quit diddling around doing things poorly and follow prescribed methods that are known to work. That would include heating solutions.

Harold

The black material is probably silver sulfide. If so, the simplest method is to melt it with about 1/2 its weight of borax and a little soda ash, with several lengths of rebar in the crucible. The rebar should be long enough to stick out of the top of the crucible so it can be easily removed before pouring. The sulfur in the silver sulfide combines with the iron and reports in the slag. When poured in a mold, the silver sinks to the bottom and should be quite pure.

The material on the right looks like the brittle silver that is plated from fixer on a rotating cathode drum or plate. It is brittle because it contains silver sulfide and it appears to be from 90 to 95% pure silver. It is purified using the same rebar method as above.

The black, crumbly stuff originally was steel wool pads. The "Hypo" (Sodium thio-sulfate. AKA sodium thionate) which contained silver, gold, palladium, and platinum, but mostly silver is scavenged by the adsorption of the Pm's on the steel wool is refreshed and ready to "fix" more photos. My method was to mix soda ash, borax, silica (or fine sand to flux the iron)
with litharge and smelt the mass to a hard lead. Then to remelt the bar to white/yellow heat and impinge hot air upon the molten mass to burn lead and left over iron. What's left is silver containing gold. If nitric acid dissolves it (from this source, it almost always does dissolve it.) remelt it again and pour into shot; dissolve the shot into dilute nitric acid. If it refuses to dissolve, remelt with more silver (inquartation), pour into shot again and dissolve in 50/50 nitric/distilled water . Heat no hotter than 154F. When it's finished, catch the solids from the bottom by decantation and filtering. The rusty left overs will mostly be gold. The liquid will be silver nitrate, a trace of lead nitric, and silver nitro-platinate and palladium nitrate.
Add Salt (NaCl) water to the nitric, and precipitate silver chloride (white cottage cheese-like), the opalescent white that doesn't settle immediately is silver chloro-platinite, which must be treated with aqua regia to dissolve the platinum and drop the rest of the silver as silver chloride. Using the search box above here at the forum search for "shotting" and "quartation" .
8) Dr. Poe

Dr. Poe said:

The black, crumbly stuff originally was steel wool pads. The "Hypo" (Sodium thio-sulfate. AKA sodium thionate) which contained silver, gold, palladium, and platinum, but mostly silver is scavenged by the adsorption of the Pm's on the steel wool is refreshed and ready to "fix" more photos. My method was to mix soda ash, borax, silica (or fine sand to flux the iron)
with litharge and smelt the mass to a hard lead. Then to remelt the bar to white/yellow heat and impinge hot air upon the molten mass to burn lead and left over iron. What's left is silver containing gold. If nitric acid dissolves it (from this source, it almost always does dissolve it.) remelt it again and pour into shot; dissolve the shot into dilute nitric acid. If it refuses to dissolve, remelt with more silver (inquartation), pour into shot again and dissolve in 50/50 nitric/distilled water . Heat no hotter than 154F. When it's finished, catch the solids from the bottom by decantation and filtering. The rusty left overs will mostly be gold. The liquid will be silver nitrate, a trace of lead nitric, and silver nitro-platinate and palladium nitrate.
Add Salt (NaCl) water to the nitric, and precipitate silver chloride (white cottage cheese-like), the opalescent white that doesn't settle immediately is silver chloro-platinite, which must be treated with aqua regia to dissolve the platinum and drop the rest of the silver as silver chloride. Using the search box above here at the forum search for "shotting" and "quartation" .
8) Dr. Poe

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If this is from a 1 hour photo shop, there are no metals involved except silver - none - zilch - no Pt, Pd, or Au. In the literature, there are some emulsions containing Pt, Au, etc., but these are for very obscure applications involving industrial x-rays. Also, Pt or Au solutions are (rarely) used to tone developed black and white photos and make them appear metallic, but I doubt if they ever have been used in a 1 hour photo shop. Even if they were, these metals wouldn't end up in the fixer.

Whether the black material is from treating fixer in a steel wool canister or in an electrolytic unit, it is still likely to be silver sulfide and can be easily melted with rebar as in the method I gave. This method is fairly standard in the industry. A place I worked processed canisters by the semi truck load. They washed the silver sulfide and silver metal out of any remaining steel wool and then dewatered it and melted it with rebar. Very simple.

Why contaminate the silver with lead or any other metal when it's pure to start with? We consistently produced 99.98% silver by simply melting the black sludge with rebar.

Dr. Poe. I realize that you are just trying to help but, in this case, I think you've stepped out of your realm of expertise. You've taken a simple thing, made some faulty assumptions, and made a long convoluted process that is complex, unnecessary, and dangerous (burning off the lead!). I would highly recommend that no one should follow your lead in this case.

Kurt:

You can also use the potassium nitrate process for silver sulphide,the step by step process has been posted by me right here in the Forum.

Hope it helps.

Kindest regards.

Manuel

Thanks guys – after Harold said –“You most likely should be melting that material with soda ash and borax, including some scrap steel. Otherwise you may be losing some of the values as sulfides.” --- it jogged my memory to a thread I read awhile back concerning this. – So I did a search using “rebar” as I remembered that being mentioned in the thread. Rebar took me to the thread titled “silver fixer” which is what I was looking for when I used “photographic fixer solutions” & got a “no match” result.

Harold – the reason I was thinking inquarting was because of what I read in Hokes about other metals being associated with photographic waste. The Au & Pt in particular. I have never worked with this kind of material so didn’t know if they where maybe significant enough (or not) to block the reaction with the acids. Another words high enough in maybe Au & Pt to block the reaction of the nitric on the Ag while at the same time the Ag blocking the reaction of the AR on the Au &/or Pt. (which is something I remember from the very first time I read Hokes – don’t need to re-read that one to understand it)

Also – the reason I did a very small melt test on the charcoal like stuff was to see if it was actually primarily a metal precipitate from the fixer or if it was primarily dried chemicals from the fixer – it was just a test of a “small” amount.

Also – I always run my acid tests (on unknowns) first at room temp then if I don’t get the expected results based on what I think it might be I put heat to the acid test – as we know, some metals require heat to cause a reaction with the acid – some don’t --- Silver & nitric shouldn’t need heat to get a reaction going – which is what caused me to stop & question what I had.

Heating the acids would not have got me on the right path anyway – being as how I am dealing with a sulphide. Also I did both a search on the forum & referred to Hokes before posting to the forum – So I guess what I am trying to say is –I think I am following procedure when dealing with an unknown. Run some tests, do some research, if your not finding the answer, ask a question.

And as always Harold – thank you for getting me on the right path with the sulphide, flux, scrap steel answer. It gave me the info I needed for a forum search that alluded me other wise.

Kurt

Juan Manuel Arcos Frank said:

Kurt:

You can also use the potassium nitrate process for silver sulphide,the step by step process has been posted by me right here in the Forum.

Hope it helps.

Kindest regards.

Manuel

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Manual - could you point me to this thread so I can read it & ad it to my tool box

Thanks Kurt

I think it is this one;
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=11061&p=108932&hilit=potassium+nitrate+process#p108932

Jim

GOLDSILVERPRO You happen to be addressing an issue of which I am way more experienced than you.
OK, use bismuth instead of lead. There is most certainly gold in color photography. Apparently you know nothing about color photography, recycling hypo or the refreshing tank. The silver is a hundred times more plentiful because the base of color photography is the silver bromide emulsion. I think that maybe you have processed a bucket before and left the gold, platinum and palladium in the silver. If you don't agree, let's move this discussion to debates and discussions where I will be glad to educate you further. Also, where you worked, I doubt if you were in on all of their secrets. Dr. Poe

Dr. Poe

Please read my feelings about your post in Debates and Discussions.

:shock:

This winter may be a long one, all of us cooped up in the house too long? I think we need a few breaths of fresh air and to cool off some. it is too early in the winter to be getting cabin fever already.

I would like to hear a friendly discussion about this we all can learn from it, but do not care to hear an ego pissin contest.

butcher said:

:shock:

This winter may be a long one, all of us cooped up in the house too long? I think we need a few breaths of fresh air and to cool off some. it is too early in the winter to be getting cabin fever already.

I would like to hear a friendly discussion about this we all can learn from it, but do not care to hear an ego pissin contest.

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I am in complete agreement with that sentiment.

jimdoc said:

I think it is this one;
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=11061&p=108932&hilit=potassium+nitrate+process#p108932

Jim

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Jim - thanks for the link - I had already read that thread after Harold pointed out to me that I was working with a sulphide & needed to use some scrap iron when melting with soda ash & borax flux. Once Harold gave me that answer here it jogged my memory to having read that thread & his mention of using rebar so rebar is what I used as a serch to find it.

Anyway - in that thread (silver fixer) Manual only mentions using potassium nitrate & then to follow his step by step instuctions posted on the forum.

So I used "potassium nitrate + silver sulphide" as a search & found his actual step by step instructions. It's a pdf down load (complete with pictures) under "Silver" with the thread title "Process to convert silver sulphide into metalic silver"

Awesome job Manual & thanks for taking the time to produce that pdf & posting it here on the forum.

I will now try both of these methods with about an oz or 2 per method to decide which method is going to work best for me to process the 14 lb of meterial i have.

But first I need to melt & cast into bars the 35 - 40 oz of silver cement I just dried from my last batch of contact points

Again thank to all of you for your help & in put here - your an awesome bunch!

Kurt

kurt said:

Harold – the reason I was thinking inquarting was because of what I read in Hokes about other metals being associated with photographic waste. The Au & Pt in particular. I have never worked with this kind of material so didn’t know if they where maybe significant enough (or not) to block the reaction with the acids. Another words high enough in maybe Au & Pt to block the reaction of the nitric on the Ag while at the same time the Ag blocking the reaction of the AR on the Au &/or Pt. (which is something I remember from the very first time I read Hokes – don’t need to re-read that one to understand it)

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Fair enough---although the likelihood that you'd encounter photographic wastes from a source that had even a small amount of either platinum or gold within is not good. While I never processed a great deal of this type of material, I never, once, found even traces of anything but silver. I expect your experience will be much the same.

Also – the reason I did a very small melt test on the charcoal like stuff was to see if it was actually primarily a metal precipitate from the fixer or if it was primarily dried chemicals from the fixer – it was just a test of a “small” amount.

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Not a problem---and the residue can be processed further for extraction of any values. Just a "heads up" that you should have used a different procedure. The point being if it is a sulfide, you most likely wouldn't realize there is any metal present. The addition of scrap steel yields results that would have, otherwise, been totally missed. With such material, if you add silver (to serve as a collector) and process without the scrap steel, you actually lose silver to the melt in that it readily combines with any sulfur that is present. It can be recovered, of course, by re-melting, adding the rebar that has been mentioned time and again. I know this to be true because I've had that very experience, albeit not from photographic wastes.

Also – I always run my acid tests (on unknowns) first at room temp then if I don’t get the expected results based on what I think it might be I put heat to the acid test – as we know, some metals require heat to cause a reaction with the acid – some don’t --- Silver & nitric shouldn’t need heat to get a reaction going – which is what caused me to stop & question what I had.

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You made a decision not based on good logic. On more than one occasion, making electrolyte with pure silver and nitric, dissolution didn't proceed immediately, and was accelerated by dilution. To say that heat helped would be an understatement. Sorry, but I still say you should have heated the solution. We most likely wouldn't be having this conversation now had you, because I truly believe that what you have is silver, and nothing more. My money says you should revisit the dilute nitric dissolution, but not until you have melted the piece once again. With all the screwing around you've done, it's entirely possible there's a thin crust of silver chloride that may prevent immediate penetration of the nitric. I've seen that on many occasions, although generally with a gold alloy, where the silver chloride turns a gray/green color.

So then, melt the glob, cool, then place in dilute nitric and dissolve until it is gone. if there's any Pt or Pd present, you'll know by the color of the solution. If it's nothing but silver, as I suspect, it will dissolve completely, leaving no solids behind. Solution will be, at best, a hint of yellow, or maybe even slightly green, depending on if there's any nitric gasses present after dissolution. Pretty simple, at least in my mind.

Heating the acids would not have got me on the right path anyway – being as how I am dealing with a sulphide.

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Wrong. You are NOT dealing with a sulfide---at least not the piece you showed. If you've seen silver in a sulfide, you'd know that wasn't the case with your piece. The piece you attempted to dissolve is metallic in nature--it is not a sulfide, It should have reacted with nitric, assuming it's silver, and I expect that it is, and that it will. Follow the tip I provided (re-melt) and do the test, only this time heat the solution.

Also I did both a search on the forum & referred to Hokes before posting to the forum – So I guess what I am trying to say is –I think I am following procedure when dealing with an unknown. Run some tests, do some research, if your not finding the answer, ask a question.

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I made an issue about heating for good reason. All too many here do not use heat. It's critical that it be used if you hope to achieve acceptable results. What may take a day to accomplish at ambient temperature may demand only a few minutes when heat is applied. Beyond that, you generally achieve better results from the volume of acid used. While there are some tests that can be accomplished at room temperature (stannous chloride and Schwerter's solution being amongst them, along with a drop of nitric on an unknown non-ferrous alloy to determine the presence of copper or nickel), heat is almost always beneficial. Next time you try a test similar to this one and you don't achieve the results you expect, make sure you apply heat before drawing any conclusions.

And as always Harold – thank you for getting me on the right path with the sulphide, flux, scrap steel answer. It gave me the info I needed for a forum search that alluded me other wise.

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I hope it helped, and I have hopes that my somewhat misguided attempt at humor in making the comments I did in my previous post are helpful as well. There's some very good information in my comments, information that will spell the difference between success and failure.

Love to hear more when you get back to the project. I'm curious if flux and scrap will increase the yield.

If, by chance, there's any traces of either gold or platinum in the material, you'll know almost immediately. Unlike the good Doc's comments, if you dissolve the resulting material, there's no way in hell it can escape you unless you're a complete fool. I expect that is not the case, but I also expect that neither of those elements will be present.

Harold

As always Harold - thanks for your feed back - your advice (as always) is well recieved. It is the kind of advice that helps to clear the stumbling stones from the path of learning.

Kurt

Dr. Poe said:

GOLDSILVERPRO You happen to be addressing an issue of which I am way more experienced than you.
OK, use bismuth instead of lead. There is most certainly gold in color photography. Apparently you know nothing about color photography, recycling hypo or the refreshing tank. The silver is a hundred times more plentiful because the base of color photography is the silver bromide emulsion. I think that maybe you have processed a bucket before and left the gold, platinum and palladium in the silver. If you don't agree, let's move this discussion to debates and discussions where I will be glad to educate you further. Also, where you worked, I doubt if you were in on all of their secrets. Dr. Poe

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Since Noxx locked the other thread, I'll continue with this one. I was wrong and Dr.Poe is right about there being gold, etc., being used as a sensitizer in at least some of the color film. However, info concerning how much is very sparse on the internet. I did find an early 70s Kodak patent that used 5 mg/Mole of silver. However, that was as a gold compound, so it would be a little less. I found one other reference that said 3mg/M of Ag. So, if the figure is, say, 3mg/M Ag, that would mean that there is $.15 in gold per $101 worth of silver or, dollar-wise, 1 part of Au per 673 parts of silver, if my math is right. Weight-wise, this is .00003 parts of Au per part of silver.

If you can provide links that more closely define these quantities (also of Pt and/or Pd), please post them.

To me, that small amount of gold isn't worth going after, especially with that long involved process that you propose. If one wanted the gold and/or Pt, the simplest method would be to melt the silver and then run it through a silver cell.

Since I was the chemist at that place, I knew everything technical that went on. We probably ran at least 100,000# of steel wool canisters during the time I was there. However, most all of this was from x-ray processing. We also ran maybe 20,000# of undeveloped "film ends" from photo processors, but, thinking back, I seem to remember Au being present in the final silver in trace amounts - too little to worry about.

In the canisters, when we melted the black sludge that had been separated from any undissolved steel wool, we didn't get all of the silver without the use of rebar. This indicates to me that at least some of the silver was in the form of silver sulfide.

In the photo, the chunk of silver on the right is most definitely from an electrolysis unit. This silver is never pure and always includes some silver sulfide. After running 1000s of pounds of this "silver chip" or "silver flake", the highest purity I've seen is about 97%. In most cases, however, the Ag from the electrolytic unit doesn't look like that. Unless the operator runs the unit perfectly, much of the silver can be in the form of a black sludge, which is mainly silver sulfide and the silver content of the dried sludge can run as low as 80%. I would bet that the black material in the photo is from an electrolytic unit and not from a steel wool canister. If a company is using an electrolytic unit, they often use a steel wool canister to "polish" or remove that last bit of silver from the solution. These canisters are generally exchanged periodically by the seller of the canisters. They take the used canisters and then pay for whatever silver they contain (uh-huh). For this reason, there would be no reason for the 1-hour photo shop to ever open a sealed canister. The stuff in the photo is from an electrolytic unit.

17 months ago I tested a silver bar made from a photo shop canister. It was sold to us as pure silver, but it contained 1% gold.
Normally, not a big deal except we were using silver salts in lieu of lead or bismuth for our cupel assays. We did this because a lot of the ore being tested had electrum which needed inquartation to process. The amount of gold contaminate from the silver that would be in the final bead (from using that bar), would be unacceptable. So I rejected that bar of silver.
It would have given a false assay. Often in some literature, a mistake is made concerning percents. 1% is erroneously printed as 0.01% (one part per ten thousand). When the writer can't make up his mind to print 0.01 or 1% . I can't tell how much chromium has replaced gold in the emulsions since I first started in 1966. I do know that cheaper film and cheaper print paper would have more chromium and less gold. At the time that one ounce troy silver bar sold for $9 and gold for around 1400.
That made the true value of that silver bar $22.91. Yet as an assay metal, it was worthless.
Wether or not it's worthwhile to further refine a silver bar to 5 9"s depends on the refiner's needs.
I do know that some companies (like Kodak) pay a premium for 999.99 silver and will reject 99% silver as unsuitable.
This will be my last reply on this subject. 8) If someone wants to discuss it further with me, they should e-mail me.
Dr. Poe

Dr. Poe said:

This will be my last reply on this subject.

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You obviously have a lot to offer to others,that want to learn about this subject.Do not make this your last public post,just do not make it "personal" when someone says you are wrong about something.
This forum is a place for others to come and learn,why not help those out? Our son taught us a good phrase that he learned in the military,I am sure you have heard it...."All gave some,some gave all".GoldSilverPro is one of the few that has given his all to this forum,and showed his humility by apologizing.The least you can do is help the new members,that come here in the future.Share your knowledge,for once it is written here,it will remain long after all of us are gone.
I apologize for what I said also,I take that sort of thing very persoanally.With a lot of help from several members,I am much better than I was 4 years ago.So please accept my apology,and keep this going.
Johnny

Dr. Poe,
I also apologize. We are all here to learn, some are here to teach or share their knowledge.
I just don't think there should be a contest of who is the smartest one here. That is what it was starting to appear to me.

Jim