# Silver scrap - film



## goldsilverpro

I just wrote this blurb and posted it on the "other" forum. I decided that you all might be interested too, so I'm also posting it here. If I've committed a heresy, let me know. I kind of look at this thing the same way I look at being a Christian. I don't have an allegiance to any Christian church but, I do have an allegiance to all the Christians.

I'm really surprised that no one has made any posts in this category. There's probably as much dollar value of silver scrap out there as there is gold scrap. And, there are probably 10 times more gold refiners than silver refiners. There's less competition in silver. I know that gold is prettier but, money is money. It's all metal. Maybe that's my problem on these forums. Since refining is my profession, I often have trouble identifying with the people that look at this as a hobby. I like playing around with this stuff too, but the profit motive is always in the back of my mind. Some of you, if you really got serious and, learn, learn, learn, could quit your day jobs. Harold and I, and a few others, are on your side and can help you get there. When you learn enough to know that you don't know it all, you'll realize that most of the info that Harold and I are providing isn't available elsewhere of the internet. Sometimes, Harold and I don't agree on the details but, both ways will work and both ways have their applications. The biggest difference between Harold and I is the the way that we approached the business. Harold picked a few scrap categories and mastered them. I, however, was all over the map, here and there, and there, and there, refining everything in sight. Both sets of experiences will benefit you.

You NEVER know it all in this business. Even though I've been in the biz for 40 years, I've learned a lot from all of you and, especially from Harold. Knowledge is King in this business. The person that knows the most always wins, moneywise. If I were an amateur, I would copy every scrap of good info from all forums and other places on the net, to my hard drive, to Word docs. There's lots of it out there, if you search. I would then organize it all into categories and, invest a bit in printer ink and print it out. I also would invest in the best books, such as Hoke, Ammen, and, maybe, Loewen. There are also a lot of booklets being sold on the web, mainly on eBay. Some are good and some are bad and it's hard to know what is what, without buying them. But, there's always something in even the bad books that can benefit you. There's always a little wheat among the tares. I even wrote a 100 page book on PM scrap refining and assay methods, in 1989. It needs a little updating and, I know a lot more today than I did 18 years ago. One day, I'll get off my duff and update it, but first I'll have to alleviate my addiction of posting on forums. I'll probably sell it digitally for a lot less money than a paper version. It costs $15-$20 just to print and ship a book version.

For those that are interested, here are a couple of forums that I have posted on in the past. The first is almost dead due to the admin's aversion to amateurs doing their own refining. If you want to read all of the posts, you have to register. After registering, go to search/author and type in my name, "chris owen". I think I made 85 posts. Also, search for the author, "reality". There are others, but I can't remember their ID's. The threads that we participated in usually had something to do with refining, much to the admin's chagrin.

http://www.recyclebiz.com/discuss/

The other is a huge plating forum. There are aspects of plating that mesh nicely with refining, especially the electrolytic part. You have to wade through about 50,000 threads but, there's good stuff on there. I've written 30-40 posts under the name "chris owen". The search engine is here, at the bottom of the page;

http://www.finishing.com/

There is something that took me 20 years to learn. That is: it's oftentimes more profitable to properly prepare the scrap and send it (maybe, go with it) to a refiner than it is to refine it yourself. It's OK to piddle around with refining small lots but, to make money, you have to gear up to run a lot more material. On small amounts, you don't really notice things like waste, chemical costs, fumes, purity, hazards, equipment, getting scrap, shipping, gear up problems, etc. When you get bigger, all of these things come into play.

Well, I've gotten way off the beaten track and better get back on.

The first silver scrap I'll touch on is silver photographic waste. There are several types: film, silver flake, fixer solution, steel wool cannisters, etc. I have a little experience in dealing with this stuff. I'll talk about film on this thread. Today, I'll only give you basic information. If you want more, I'll go into more detail later. 

About 15 years ago, I had a small set up for running about 1000#/day of film, max. I used a stainless steel tumbler from a scrap industrial clothes dryer. My setup was in a scrap metal yard and, therefore, most of my equipment was cheap or free. For a tank, some farmer brought a 375 gal stainless milk cooler in for scrap. I think we paid him $9. It was perfect for the tumbler. It was a tank 6' long by 3' wide with a rounded bottom. Under the stainless, there were insulated cooling coils which we converted to heating coils by circulating water from a standard hot water heater. The solution was a non-toxic enzyme/baking soda mix that ran at about 100 degrees F. It smelled like a septic tank. You can also use a weak (3% -10%), non-odor, sodium hydroxide solution. The silver/emulsion came off as a black sludge. Every evening we stirred the solution and pumped it up to settling tanks. Next morning, we syphoned the solution, off the sludge, back into the strip tank. The same solution was used over and over. The sludge was treated and melted to a purity of 99.98%. Film silver is very pure to start with. If you don't contaminate it, you don't have to refine it. All you have to do it burn the sludge and melt it.

A while back, I spent 4 years, part time, running film assays for a major film refiner. I ran about 30 assays a week, for a total of about 6000 assays. This represented about 50 million pounds of every type film under the sun. I know values.

In order of quantity available: X-ray, litho, industrial, others. The X-ray and litho make up about 95%+ of all film. There is twice as much X-ray as litho. The medical is going digital so, these ratios probably have changed. In order of value: Industrial, litho, X-ray. When I left, the X-ray contained 0.1 ozs/# - today is $1.32/#. When I left, new, lo-silver X-ray started lowering these numbers. The best newspaper litho runs about 0.24 oz/# - $3.19/#. Average black Industrial runs about 0.25 - 0.3. These values are for black processed film. Green undeveloped film runs a lot more. There are about 20 common categories of film, each with it's own set of values. In a category, there are several quality levels.

I'm taking questions.


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## lazersteve

Chris, 

Thank you for being kind enough to share these trade secrets with the forum. I share your perspective on the Christian subject.

The first question I have is very obvious:

Where do you get enough film to make the project profitable?

Steve


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## Noxx

> I just wrote this blurb and posted it on the "other" forum. I decided that you all might be interested too, so I'm also posting it here. If I've committed a heresy, let me know.


No, It's a very good idea, thank you.



> I'm really surprised that no one has made any posts in this category.


Well, this is because this category is only 3 days old lol. :lol: 


This is really great info ! I would like to refine silver too but I haven't found any sources yet...

I plan to start my own business me too (and work at part time). But I must get much more scrap... For the moment I only deal with small quantities.


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## Lucia

Hello Chris, 
Thank you for sharing with us your knowledge. We have right now over 10 pounds of silver contacts (industrial) and I would like to know which is the best way to refine it and of course what kind of chemicals should we buy.


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## austexjwlry

Yesterday we came across a 1,600 ft spool of film almost 16 mm wide on the plastic spool weighing almost 4lbs. I cut up about 2 oz covered with full strength nitric. It went to work with very little fuming or the usual red cloud. The film cleared in color then became a celluloid mess,just formed a glob in my coffee pot.The nitric turned a pinky/red color, I'm not sure why?
Then I decided to burn some in a large cast iron frying pan. It burned well with the assistance of a bernzomatic torch,creating less smoke than expected. My wife said it smelled like burnt candy! We only burnt a few onces, then covered the ash with nitric full strength. It went to work right away with to usual red fumes. I have'nt precip. with salt yet. 
I'll have to burn the rest of it at our place in the country to avoid upsetting our neighbors here in town.I've read the celluloid bace has value if you have enough.
Not much fun for very little money!

Thanks for your info.
Wayne


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## goldsilverpro

What kind of film do you have? Is it color or black and white? There's no silver on developed color film. All of the silver goes into the chemistry. Dyes are left over and this could be the source of your red color.


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## austexjwlry

This film has the name Plio-Magic on the spoon, does this possibly mean the film is made by that company or just the spool? Its black & white film for sure.I got it out of the dumpster at apts. across the street from us. A homeless friend of ours saw me get it and told me there had been 2 more rolls in it before the dumped it last week. He said he would collect them for me from now on! We live 5 blocks from the university of Texas and the students throw away a lot of computers working or not. This guy just leaves it by my front door and I pay him when I see him next. It pays to be nice to everyone!
Thank You Again,
Wayne


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## aflacglobal

Don't know about that film. :shock: :shock: 

Great , great post Chris. You sound like me. All over the board. can't just learn one thing. Interesting topic about silver v.s. gold. 

I wondered if that was your book.
I like the money to. Production>>> That's my way of thinking.

Ralph


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## goldsilverpro

You've got your work cut out for you, Austex. Laborwise, doing film on reels is the worst, especially, when you don't have a shreader. That film is long! It won't even hardly burn, without unreeling it. Youll have to cut it up. If you have a band saw, you might try cutting the reel and film in half. That could save a lot of work. It might, however, weld the cut ends together and make the pieces harder to separate. Try it if you can. I can't think of any other type saw that might work.

Any chemical that you use will make the gelatin all stick together. I wouldn't run much at a time - maybe, 1/2 pound in a bucket or plastic tray. You'll probably have to use gloved hands and work the strips of film in the solution, in order for the chemical to get in between the film.

Ideally, you could use a long (or deep) tank, with the reel(s) of film at one end and a take-up reel(s) at the other. You would have to use a solution that would work fast. A little agitation will help. I think that some strength of nitric might work the fastest. 

Another advantage of nitric is that all the silver becomes dissolved. This makes the separation of silver and plastic simpler.

Don't expect much from this type film. I wouldn't expect much over 1/2 to 1 ounce of silver on the 4#. Maybe less, depending on how much black is on the film. The only way to process this type of film, profitably, is to process it in tonage weights, in a full fledged process line. 

I have never used nitric to strip film. I have played with it and I know what happens. I had better methods but, for you as a hobbyest with a small amount of film, I think nitric would work the best. It's the simplest. 

*1)* Concentrated nitric was a bad choice. To experiment, I would start with about 35% nitric, by volume. I think that it will be too strong but, when you start high, you can simply go lower by adding an increment of distilled water. It is my guess that 25% (and, maybe a little less - maybe only 10%) will be the best. You want a strength that is quick enough, yet not too strong to be uncomfortable to work with. Try to use the lowest strength that still strips pretty fast. The silver is stripped when the black is gone.

*2)* First off, try putting about 1/2#, in 6" strips, in a 5 gal. plastic bucket or about a 3 gallon plastic tray. Cover the film with about 3"-4" total of solution. Work the film with your gloved hands until the black is gone. Remove the plastic with your glove, shake it a bit and put it in some rinse water.

*3)* Add more film to the same solution. When it slows down too much or stops working, add a little nitric and maybe about the same amount of water. You may have to sooner or later make up a fresh batch(s). 

*4)* Collect all the solutions and rinses together in a bucket(s). Either allow the crap to settle and pour the clean solution off or filter the whole thing. 

*5)* You can get the silver out in 2 ways. You can either make silver chloride or you make silver metal directly. In this case, the silver chloride will ultimately make much purer metal. The silver on film is quite pure. If you don't contaminate it with other metals, it will end up pure. To cement the silver metal out directly with copper, you will contaminate the silver, somewhat.

If you choose the silver chloride method, add salt water or HCl, in increments - stir after adding, until no more silver chloride drops out (observe white cloud). Keep the silver chloride wet at all times. Either use the Karo syrup/lye or aluminum method to convert to silver metal. It's all somewhere on the forum.


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## fafrd

i have been reading this and i am wodering what type of chemicals would you use goldsilverpro if you were a joe of the streets to process used film? i have a supplier of used film (about 65-80 covered in black ) that comes from making voting ballots. i get about 40 lbs a month from them. plus i have some used dental film and pet x-ray. i could save this up for a year and send it out to be refined but if i can do it in small doses at home cheap enough it might be worth it .


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## goldsilverpro

I'm assuming you want to make some money on this. Unless you can generate several thousand pounds a month, you probably should save the film and sell it. You should get between $1 and $1.50 per pound, depending how close your buyer is to the refiner. By your description, your film is about C Litho. Maybe, C+. Keep it dry.


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## fafrd

thank you goldsilverpro i was just going to save it for right now and wait for larger amounts. been trying to get the 2 local hospitals to tell me what they are doing with their used x-ray films. according to a person that works at one of them they just threw 3 stand up freezer boxes of used x-ray in the garbage. my bad for not acting sooner


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## tyoon21

Hi y'all...just ran across this thread and found it really interesting.

As to gathering x-ray film, one thing I would consider would be to contact dental or medical offices. Most states have a limit as to how long doctors have to hold onto the charts. Once the limit is up, most docs want to get rid of these old charts as office space is limited. Offer to take old charts off their hands and provide secure destruction for free or even charge a small amount for your time. Granted, it takes a long time to shred all the charts and paper, but you will get a lot of x-rays as well as white ledger paper which can be sold as well.

Dental offices are a great source of x-rays. Unlike our physician counterparts, all dentists carry x-rays on all their patients. Dentists tend to take x-rays on a 6 month basis to check for cavities or periodontal disease so the amount of x-rays can really pile up in offices. As more offices go digital, dentists are looking for more ways to get rid of the paper and will gladly give you charts and x-rays for recycling / refining. Also, you can ask them for the lead foils that come with the x-rays. Most of the time dentists will keep the lead separate because if OSHA comes around and finds lead in your trash it could be an unpleasant visit. 

On a personal note, I generate anywhere between 15 - 20 pounds of scrap x-rays a month from casual chart destruction. This number could greatly increase if I had someone come and just take all these charts off my hands. Right now I save it and hopefully can sell it as a large lot.

Not sure what would be more profitable, refining it yourself or selling it. Most companies I called only want 1000 pounds or more at a time for a decent payout. I found a local company in my area that was offering 20 cents a pound. Not sure if it's a fair price or not.

As for refining, I heard you can soak your x-rays in fixer solution for an extended period of time to wash the silver off. Then by using steel wool you can exchange the silver for the iron ions. Companies will buy the steel wool for refining. Being new to the whole recovery / refining field, I don't know the reliability of this technique. Does anyone know of a step by step process for small timers?

Hope this helps! Please feel free to message me anytime.

Tom


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## goldsilverpro

As I mentioned before, I once spent 4 years doing some 6000 assays for one of the largest film refiners. During that time, they processed about 50 million pounds of film. Every type of film known to man was represented except for dental x-rays. To me, the reason was obvious. Dental x-rays are so small in size that the labor, collection, and other costs would override any profits. This is an educated guess, but I would imagine it would take 10,000, or more, of them to get 20 pounds. Also, there is the paper problem.

The 20 cents per pound sounds low. I haven't assayed any of them, but I would assume the silver content would be about the same as medical x-rays. They run about 0.1 troy ounce of silver per pound. At today's silver market of $13.28, the silver content would average about $1.33/pound. The more black that's on the film, the higher the silver. 

There are usually 1 or 2 sets of middle men in the film buying business and everyone has to make a profit. The last middle man has to go to the expense of collecting, storing, sorting, and shipping the material to the refiner. There aren't many film refiners around but, if you can find one, you will get a higher price by selling directly to them and avoiding the middle men. The company I worked for bought any sized lot at their dock. On the east coast, the refiners are mainly in South Carolina and Tennessee. I think there is a incomplete list of buyers and refiners on the Kodak website.

The fixer/steel wool is not a good idea, especially in the small quantities you're talking about. It's impossible to just look at the steel wool and tell how much silver is in it. It's never uniform and therefore it can't be simply sampled and assayed. Therefore, the buyer or refiner will pay you very little for it, just to cover their butts. There are also inherent problems in collecting all of the silver from the fixer, in the steel wool. There are companies that make canisters of steel wool and other metals for silver removal from fixer. The solution is pumped through the cannister at a fairly slow rate. Here again, though, you'll have problems getting a good value when selling them.

Unless you get quite large, maybe several thousand pounds per month, you're better off selling the film. If you want to play with refining, you can strip off the emulsion, along with the silver, using a 5% to 10% sodium hydroxide solution, at about 100 degrees F for the 10% NaOH and probably about 150F for the 5%. Agitate the film while stripping. It will go slow because, when wet, the film sticks together and the solution has to work it's way between the layers. You might put the film in a small plastic bucket, with holes drilled in it, and bob it up and down in the solution. *Wear a full plastic face shield and gloves - a drop of NaOH can blind you.* Remove and rinse the clear film plastic (PET), when stripped, and let the sludge settle. Pour off the liquid and filter and rinse the sludge. Burn the sludge outside (it really puts off vile and, most probably, toxic fumes) to get rid of the emulsion. Melt the residue in a crucible furnace with borax and a small amount of soda ash. If you haven't contaminated it with other metals, the silver should end up about 99.95% pure. The sodium hydroxide method is the most common method used commercially. There is also a very safe enzyme/baking soda method that is sometimes used but, it makes the entire building smell like an outhouse..

You can also use dilute hydrochloric acid to strip the emulsion/silver. The silver will be converted to silver chloride. You can then use the Karo syrup method to convert this to silver metal. The hydrochloric method is not used commercially because of the fumes and it's corrosive properties. Also, silver chloride is a bear to work with, especially in large quantities.

Chemically, the very best way to process film is in a cyanide solution. The film is stripped and the silver is directly plated out of the same solution. The same solution is used over and over. In the '70's or early '80's, if I remember right, some guy died in a film processing plant in Chicago. The TV show, 60 Minutes, did a blurb on it. Since then, no more cyanide is being used for film, at least not in the US.

As far as I know, no one is collecting dental x-rays. If anyone was, I would have seen it at that place that I worked. It's one of those items that's probably thrown away, due to the expense of collecting it. If you can figure a way to collect it and handle it, profitably, you'll be a rich man. Every dentist has only a little bit of it but, there are a lot of dentists. Maybe you could guarantee to give half (or, ?%) of your profits to a good charity, if the dentists will separate it and ship only the film to you. Dentists may bite on that ploy.

Every post I make about film, I warn people to *NEVER allow the film to get wet, if you plan on selling it.* If you do, you'll get much less money for it. When it dries, it will be glued together and can't be easily processed. It can be incinerated (very dense toxic black smoke) to light gray ash and then the ash can be melted to get the silver. Before EPA, this was the main method (cyanide was probably #2) that was used for all film. During incineration, about 30% of the silver goes up in smoke. Commercially, the smoke was collected in a high dollar baghouse.

You might also ask the dentists if they have any out-of-date undeveloped (green) film or scrap green film that has been accidentally exposed. Green film runs about double the value of developed film.

You may find that more money can be made from just collecting the lead foil. You also should ask about their dental gold scrap after you learn how to buy it. Dentists will also have silver bearing fixer solutions containing about half of the silver that was on the film. They may dump it down the drain, although, if it contains silver, it is illegal to do so. The smaller dentists may use steel wool cartridges to remove the silver. Usually, they have an exchange contract with the cartridge provider. You may also find that large dental offices have electrolytic cells, with rotating cathodes, to plate the silver out of the fixer solutions. The resulting silver is called "silver flake." It will usually run from 60% (or, worse, especially when wet) to 98% silver. The lower value flake is black and slimy and the good stuff is hard and white in color. Before weighing the flake, it should be dried out. Heat drying produces a lot of stink, since the black slimy stuff contains a lot of sulfur.


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## Harold_V

goldsilverpro said:


> In the '70's or early '80's, if I remember right, some guy died in a film processing plant in Chicago.



That's correct. The parties responsible for his death were charged with murder. Several were tried and convicted in Illinois, but one of them, a Utah resident, and son of the man that laughed in my face when I told him that I wanted to learn to refine, was protected by the State of Utah, which refused to extradite him for prosecution. As I understand it, those that were convicted had the conviction overturned at a later date. 

Here's a link that gives some of the details on the attempt to prosecute the Utah connection:

http://www.highbeam.com/doc/1P2-3743516.html

As an aside, here's a link that discusses the spent film.

spent film

Harold


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## tyoon21

Great post goldsilverpro! I think you are right about just collecting and selling the x-rays. Makes sense for us small timers. Especially since the process sounds fairly toxic and complicated.

As for the dental x-rays I am finding that the tiny x-rays are indeed a pain in the rear to collect. They usually come in a series of 2, 4, or 16 and are mounted in a plastic film cover. This is getting a little tedious to remove and collect.

However, there are newer x-rays that dentists are taking which are much larger, don't have paper labels (usually) and are in one piece. Dentists, and dental specialists such as orthodontists, periodontists, and oral surgeons will take films called panoramic's which will x-ray the whole mouth. Orthodontists will also have skull films called lateral cephalmetrics which are large as well. Dental specialists tend to only see their patients for a very short period of time and have tons of these things lying around, especially the oral surgeons.

Also, periodontists and oral surgeons are using CT scans more often for larger bone grafting and dental implant surgery. Generally, these scans are really large and bulky and for some reason only about 25% of the actual scans are used in surgery, the rest are thrown away or hidden in some closet.

I wish I knew about the "green film". I just dumped some when I was cleaning out my closets. Dental schools would be a great source of this as they order film by the bulk and a lot of times don't use it all. All dental schools have a radiology department and there are tons of students taking films. Since they are also learning, they waste a ton of film which most of the time goes in the garbage. Also, the schools will collect lead foils which I am sure they would be happy to give to anyone that would haul it away.


Thanks again for all the help!

Tom


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## goldsilverpro

Good post, Tom. I learned a lot from it. Thinking back, they took a panoramic x-ray the last time I went to the dentist. I also hadn't thought of dental schools as a source of scrap.

Chris


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## hyderconsulting

Just a little side note, Harold, but that cyanide poisoning case was a landmark case in that it resulted in Material Safety Data Sheets being born and required by law whenever any chemicals are shipped are handled by anyone. The operators of that refinery had scrapped off the content labels and the skull and crossbones off the barrels of cyanide the Polish worker was using. He didn't know what he was handling. Not a nice bunch of people to work for!!!!!! Regards, Chris.


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## Harold_V

hyderconsulting said:


> Not a nice bunch of people to work for!!!!!! Regards, Chris.



Heh! 

If my contact with Byron McKay (the father of Michael McKay) is any example, I'm in total agreement. I went to this man with a good introduction, he having worked for the grandfather of my (then) wife in the sampling mill of a large smelter in Utah (now defunct). He was indebted to the grandfather for considerable education, which eventually lead to his founding his refinery. That they were not a nice bunch of people to work for is an understatement. 


I was unaware of that case being the basis of requirements for MSDS. Thanks, Chris. 

Harold


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## junkelly

Thanks all for the advice about silver film. I have about 100# of x-rays that I would like to process. I understand this is more of a hobby or to see 'if I can do it' than a profit making venture. I am thinking about rinsing the films with dilute NaOH and then processing the black sludge. I am just wondering if it is recommended to use distilled (Cl-free) water during any of these steps, or if it is acceptable to use tap water.

JunKelly


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## goldsilverpro

If they're modern medical x-rays, you can expect about 10 oz of silver, total, from your 100 pounds. If you run full sheets, you will find that the sheets will stick together, causing the stripping to go very, very slowly and complete stripping may be impossible. Since you're just playing around, I would suggest you first run the film, a sheet at a time, through an old decent paper shredder. This will make the stripping go much faster and you will be less frustrated. 

Some of the newer film may be Dryview, which is developed by heat instead of by chemicals. It will strip slower and you may find that you'll have to raise the temperature of the solution considerably. Dryview is detected by *briefly* holding a lighter underneath a non-black clear area of the film - maybe on the border. If it is Dryview, the spot will turn black. This has to be done right. If you don't leave the flame long enough, nothing will happen. If too long, even regular film will burn and turn black, although the black color is different - it's more like a very dark brown. A second or two or three should be long enough. Some big film refiners won't buy Dryview because it's such a pain to process. Some Dryview requires special in-house secret solutions to get good stripping. 

Stripping is complete when all of the black has been removed and you're left with just blue (usually) plastic.

Stripping time in a NaOH solution is a function of chemical strength and temperature. The weaker the NaOH, the higher the temperature required. A 3% solution requires about 200 F. A 10% solution, about 100 F to 120 F. With the 10% solution, you may get away with room temperature but it may go slow. Tumbling is always best in production. In your case, I would drill some holes in a small bucket, put some film in it, and slowly bob it up and down, every so often, in the solution that is contained in a larger bucket. After stripping, bob the film in a couple of buckets containing rinse water. Wear a full plastic face shield to keep drops of NaOH solution from flying into your eyes. After the silver/emulsion sludge has settled and been removed, the solution can be reused, over and over. If if slows down, you can add a little more NaOH. Never get NaOH under your fingernails or you'll be in pain for a long time. Don't ask me how I know this. Always wear good rubber gloves with no pin holes in them.

Everyone uses tap water. You could lose traces of silver as silver chloride, however. Some of the chlorine in the water can be eliminated by filling buckets with water and, with occasional stirring, letting the water stand for a few days before using it. As Harold said in a recent post, the value of the silver lost is less than the cost of distilled water.


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## Harold_V

goldsilverpro said:


> Never get NaOH under your fingernails or you'll be in pain for a long time. Don't ask me how I know this. Always wear good rubber gloves with no pin holes in them.




Speaking from the position of a guy that once got a direct hit in the eye with a drop of nitric acid (which popped out of a beaker as it was poured), be damned careful about not getting any NaOH in your eyes. 

It took but seconds for the surface of my eyeball to peel. It turned an ugly yellow color, then fell off. I feared I had done permanent damage. A quick trip to an ophthalmologist was very revealing. He informed me how fortunate I was (sure as hell didn't feel like it) having been exposed to nitric instead of lye. He said that when lye enters the human eye, one has but 15 seconds to prevent blindness. According to what he said, the human body can neutralize nitric fairly easily, which is not the case with lye. It continues to do damage until it has been totally consumed--which is far beyond the time it takes to blind an eye. 

Be very careful.

Harold

PS-----my eye turned out fine, although it did take several days.


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## loco

GSP!!!! Harold !!! or anyone that can HELP!! 

I have come into some possible good luck today while at my day job (telecommunications contractor...mostly 2 way communication satellite systems IE: internet) I was talking to my customer who happens to be be in the X-Ray business and says he personally goes threw about 2 semi's loads worth of equipment monthly and knows 8 other guys that do the exact same as him. They have the scrap parts and so far don't do much with it from my understanding. They know it contains silver but not much else. I'm just courious if you might be able to help me see if this is indeed something I would like to wet my feet with. The help is GREATLY APPRECIATED!!

-Rich


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## Harold_V

Can't provide much input until you can identify the nature of the material. If it's plated, could be it wouldn't be worth messing with. Can you provide more information?

Harold


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## loco

ok found out some more info on it. appears the guys company works on a system called Pack or pac or paq or something like that. basicly from my understanding it is what they use to backup x-rays, on a regular basis, digitally. It has something to do with networking so gold may also be found in it. And today when the guy called me back he offered me a job. why?? especially when I told him my focus was I am making an effort to check out refining/recovery of pm's. anyone know anything about this system and why they need such regular serviceing. the gent said he's been doing it for the last 47 yrs.


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## Harold_V

Interesting, but totally lacking in information regards what you might expect in the way of metals. You need far more information before you can expect a helpful response, unless one of the readers has knowledge of the system you mentioned. I'm at a complete loss.

Harold


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## loco

ok sorry I don't know more. but I can clarify thanks to good ol' google it is called PACS or PAC system. the PACS returned the best results when I googled "x-ray+PACS" minus qoutes. not sure that helps any more but that is all I know so far.


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## goldsilverpro

From what I read, it sounds like PACS is a non-silver, digital x-ray system.


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## GeeDub

Hi GSP.

This is going to sound like a strange one, but did you know what the gelatin turned into after the enzymes?

I decided to atone for the (vast) ecological sins of my youth by developing zero residue refining technology. This means nothing comes out that is not water vapor, CO2 (I don't accept that as a pollutant), or a usable product. (Many tell me it can't be done, I love a challenge).

I expect to use the film waste as part of a solid industrial fuel product. I would try to sell it as scrap PETE, but as I understand it some new films are mixed with another plastic. Saw a patent on separating the 2, but I think it would be easier for me to turn into fuel. 

My thinking for the gelatin residue is fertilizer but I would like to know what I would be starting with.
-G


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## goldsilverpro

The gelatin breaks down to Amino acids, I think.


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## wolfville

hi I have 2000 kg of virgin xray film , and i get 500 kg of dryview, i really need help, I'm trying with the process of manuel, fixer, sodium sulpnide, salitre, borax, but. There are other method? , and , what i can do with the dryview films?,i get this films for free, please help me.
ERICK


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## jimdoc

wolfville said:


> HI I HAVE 2000 KG OF VIRGIN X RAY FILM, AND I CAN GET 5000 KG OF DRYVIEW, I REALLY NEED HELP , I'M TRYING WITH THE PROCESS OF MANUEL FIXER SODIUM SULPHIDE, SALITRE, BORAX, BUT THERE ARE OTHER BETTER METHOD? AND WITH THE DRYVIEW?, I CAN GET THIS FILM FOR FREE, SO I CAN'T SAY NO, PLEASE HELP ME
> ERICK



Please edit out the all caps.
It will help you get a response.

Jim


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## wolfville

excuse me, i need a good method to recover silver from dryview films and virgin x-ray film, thanks
Erick


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## wilstyle

Hi There,

This might sound stupid but why does B&W movie films contain silver but color movie films don't?


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## goldsilverpro

wolfville said:


> excuse me, i need a good method to recover silver from dryview films and virgin x-ray film, thanks
> Erick



Standard virgin rare earth x-ray film is usually processed with hot sodium hydroxide (NaOH) solutions. The NaOH breaks down the emulsion, converts the silver halides to silver oxide, and removes the emulsion and silver oxide from the plastic film base, forming a sludge. The sludge is then filtered, rinsed, incinerated, and the ash is flux melted and the pure silver is poured into bars.

Another way is to leach the virgin film in a sodium thiosulfate (hypo) solution. This dissolves the silver halides and the solution is the put into an electrolytic cell with a rotating cathode to plate out the silver.

Dryview is different. As I understand it, the silver compound is applied to a thin layer of mylar (saran) which is applied to the PET plastic film base. To remove the silver, the bond between the mylar and PET must be broken. This requires reaction in a very hot alkaline solution with the addition of a 2 or 3 proprietary additives for an extended period of time. There's a lot more to this than I've mentioned. Very difficult to do. This company claims to be the only one to do this successfully. 
http://www.petag.net/


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## goldsilverpro

wilstyle said:


> Hi There,
> 
> This might sound stupid but why does B&W movie films contain silver but color movie films don't?


Virgin color films contain quite a bit of silver. During the developing, all of the silver is removed from the film and is replaced by dyes, as I understand it.


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## ilikesilver

I love this post thank you folks. film on another hand is way out of my league, living in such a little state like vermont, the rural factor would kill me trying to find stuff like that. As the avatar name suggest, yes i like silver, and thats what i do concentrate on. gold and platinum is not my thing. When i first got into scraping, boy i would scrap everything. But it was out of control, then one day i looked at my pile of stuff that ive been building up and just decided to concentrate on one thing. silver it is, i dont think its easier then gold or platinum, i just like it better for some weird reason. so slowly i have traded off some of my piles.

What i have thought of doing is finding someone that would take my PM materieals, say for instance all my chips and process them, they keep the gold and they send me the silver back. I know that i would probably loose in the end, by it would be a means to a end. what do you all think? tim


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## medusa

goldsilverpro said:


> .... The silver/emulsion came off as a black sludge. Every evening we stirred the solution and pumped it up to settling tanks. Next morning, we syphoned the solution, off the sludge, back into the strip tank. The same solution was used over and over. The sludge was treated and melted to a purity of 99.98%. Film silver is very pure to start with. If you don't contaminate it, you don't have to refine it. All you have to do it burn the sludge and melt it....
> 
> 
> 
> I'm taking questions.



Please excuse the bumping of an ancient thread, but rather than create a new one...

I'm a jeweller and my husband is a photographer and has about 50l of spent fix which is being stored in a dustbin in the yard. We know we can convert the silver in the fix by dumping some wire wool in it, but what about the black sludge which will be produced? Most of the refining stuff I've read says that the sludge should be taken for refining, but these are photographers and need very pure stuff. I would really like to use the silver recovered to make an anniversary gift... a kind of mixing of our two crafts if you like. So the silver doesn't have to be 99.99% pure, in fact I'd need to add some of my old 800 fineness to make it more useable. 

I'd like to know do I need to refine the sludge and if so, how (simplest DIY method please!) or, can I just smelt it down and work from the ingots produced.

Look forward to hearing suggestions.

M


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## FrugalRefiner

medusa said:


> Please excuse the bumping of an ancient thread, but rather than create a new one...
> 
> I'm a jeweller and my husband is a photographer and has about 50l of spent fix which is being stored in a dustbin in the yard. We know we can convert the silver in the fix by dumping some wire wool in it, but what about the black sludge which will be produced? Most of the refining stuff I've read says that the sludge should be taken for refining, but these are photographers and need very pure stuff. I would really like to use the silver recovered to make an anniversary gift... a kind of mixing of our two crafts if you like. So the silver doesn't have to be 99.99% pure, in fact I'd need to add some of my old 800 fineness to make it more useable.
> 
> I'd like to know do I need to refine the sludge and if so, how (simplest DIY method please!) or, can I just smelt it down and work from the ingots produced.
> 
> Look forward to hearing suggestions.
> 
> M


M,

Welcome to the forum. You can find all the information you need here on the forum, but it will take some time and research. There are several ways to recover the silver from fixer. If you use the search function found at the top of each page you'll find numerous posts on the subject. Try a search with the words "recover silver fixer", without the quotes.

The first rule is to be safe in everything you do. Before you jump into any of the processes you see discussed here, be sure you understand the potential hazards and do everything you can to minimize the risks. Read EVERYTHING in the Safety section of the forum, especially the Dealing with Waste topic. No amount of precious metal is worth jeopardizing your health or the health of those around you. 

Just to get you started, here's a link to a thread in the "Silver" category of the forum titled: Recover Silver From Fixer.

Once you recover and refine your silver, you would be better off adding fresh copper to it to alloy to the final fineness you desire. Each time you melt an alloy that contains base metals (e.g., the copper in your 800 silver), some of the base metals will oxidize. Remelting your 800 will produce more oxides. These oxides will result in porousity in your finished product. Pure, fresh copper is easy to find and inexpensive. Copper wire used in home wiring is electrolytically pure. So starting with refined silver and copper wire, you can create any alloy you want, melt it only once, and experience a minimum amount of problems.

Dave


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## medusa

Thank you for the welcome, Dave 

My bad, I did a search for "Silver Fixer sludge" and alighted on this discussion.

I regularly use Hydrochloric and Hydrofluoric acids in my workshop (or rather yard... hydrofluoric is pretty horrifying stuff), so I'm pretty up to date on safety and storage but some useful other info in there.

I'll ask in the correct thread.

M


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## FrugalRefiner

When I first joined the forum I found the search function less than helpful. The more you read, the more you will learn the keywords that will help you find what you seek.

I hope you keep some calcium gluconate gel on hand at all times. Hydrofluoric acid is indeed some horrifying stuff. I can't imagine anything I'd need to do in my yard that would be worth exposing myself to its dangers.

The first rule here is to be safe in everything you do.

Dave


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## medusa

Hi Dave,

the HFA is for removing enamel. Not something I use on a daily basis thank heavens and I tend to save up all enamel stripping I need to do so I can do it in bulk once or twice a year. I keep powdered lime to hand in case of accidents although I have a kind of outdoor double gloved chamber thing I do it in plus respirator. 

I try to use minimal amounts of acid of any kind and have switched from nitric acid to Ferric Nitrate for etching because it's rather less scary.

chemistry was never my strong point, but hopefully I'll manage to get something out of all this fix.

I'll do some small tests comparing the zinc and wire wool methods.


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## FrugalRefiner

M,

You obviously have more experience using HF than I. I haven't touched the stuff since I was a chemistry aid in high school. But I don't believe powdered lime is a substitute for calcium gluconate. HF passes through the skin quite quickly. If you're going to keep HF around, you MUST keep some calcium gluconate gel on hand.

Starting with some small tests on your fixer is definitely the way to go. Find what works for you, then scale up a little at a time.

Stay safe,

Dave


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## ayu

Hi Goldsilverpro, thank you for your effort sharing all your info and experience with us, particular those newbies. 

I have a question please. What is the best method to recover silver from some kind of Ag/AgCl electrode. This kind of electrode is made of very thin layer of Ag and AgCl on plastic film, i.e. Ag on the film, AgCl on the Ag. The electrode is very small, 16mm x 6mm. From one side it can see shining silver color, from the other side, half is the shining and the other half color likes unused photographic film (brown). I guess the silver density is pretty high.

Is it the method NaOH+Sugar the better one for starter? Or maybe only NaOH alone plus heat? Well, for a newbie, can you teach me what equipment should I own to start? Thank you. 

BTW, I can send you some of the electrode see how much silver you can get out of it! 8)


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## goldsilverpro

ayu said:


> Hi Goldsilverpro, thank you for your effort sharing all your info and experience with us, particular those newbies.
> 
> I have a question please. What is the best method to recover silver from some kind of Ag/AgCl electrode. This kind of electrode is made of very thin layer of Ag and AgCl on plastic film, i.e. Ag on the film, AgCl on the Ag. The electrode is very small, 16mm x 6mm. From one side it can see shining silver color, from the other side, half is the shining and the other half color likes unused photographic film (brown). I guess the silver density is pretty high.
> 
> Is it the method NaOH+Sugar the better one for starter? Or maybe only NaOH alone plus heat? Well, for a newbie, can you teach me what equipment should I own to start? Thank you.
> 
> BTW, I can send you some of the electrode see how much silver you can get out of it! 8)



Assuming the electrode is composed of only Ag and AgCl, I would probably dissolve the Ag in 50/50 HNO3, precipitate AgCl with HCl, and convert all to Ag with Karo syrup and NaOH.


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## ayu

Thank GSP for your reply. I don't think HNO3 is cheat from the market, so does bleach (HClO) react with Ag to obtain AgCl? I believe Ag can't even react with high concentrate HCl alone. Since there is free Ag already, can I just use NaOH only to deal with the AgCl? Hm, but how to strip Ag off the plastic film? Can I burn the electrode film to get the free Ag first then deal with the AgCl?

GSP, can I send some to you per the address you mention on your e-book purchase post? For sure, when I start my hobby I will buy your ebook. That would be a short cut to me to search and learn... :lol: If you have time do you mind helping me to find out how much Ag can be recovered per electrode? Thank you in advance.


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## JHS

That would be a short cut to me to search and learn... :lol: If you have time do you mind helping me to find out how much Ag can be recovered per electrode? Thank you in advance.[/quote]

You will find that shortcuts are fiercely frowned upon on the forum.
if you want to learn,then you should start by learning the necessary safety first.
safety is paramount.you would not tell your child to cross the street,without first teaching him how.
then read hoke,as Harold said until you understand.
then use the search to gain the understanding you did not get from hoke.
then ask an educated question.
it has been pointed out that if you just go about asking newby questions on the forum,that you want to be spoon fed and that will now get you banned from the forum.
SAFETY FIRST you can fix a mess,but not a lung.
john


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## ayu

From where and what makes you think i am not concerned with safety? Nothing wrong with 'search and learn', is it?


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## goldsilverpro

ayu,

Don't send me anything. I'm not set up to do any lab work.


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## rickbb

ayu said:


> Thank GSP for your reply. I don't think HNO3 is cheat from the market, so does bleach (HClO) react with Ag to obtain AgCl? I believe Ag can't even react with high concentrate HCl alone. Since there is free Ag already, can I just use NaOH only to deal with the AgCl? Hm, but how to strip Ag off the plastic film? Can I burn the electrode film to get the free Ag first then deal with the AgCl?
> 
> GSP, can I send some to you per the address you mention on your e-book purchase post? For sure, when I start my hobby I will buy your ebook. That would be a short cut to me to search and learn... :lol: If you have time do you mind helping me to find out how much Ag can be recovered per electrode? Thank you in advance.



I have seen a patent that uses bleach to strip used x-ray film. But it dissolves the gelatin emulsion and allows the Ag salts to drop to the bottom of the stripping solution. Not sure that would work on your material. (And it seems the bleach is used up quickly in the process.)


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## ayu

thank you all. I have tried to boil with water but Ag/AgCl layers do not peel off. I add some HCl then they do. I collect and dry them up, plan to burn them and see what remains.


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## butcher

ayu,

Do you have pictures of the electrodes?

I do not know what you have, but maybe I can give you some things to think about.

silver chloride if heated can decompose to silver and chlorine, But the silver chlorides can also be volatile so you can burn off your silver in the white smoke, so normally we do not want to try and melt silver chloride, we normally change it back to silver metal before melting using one of the conversion methods, like NaOH and karo syrup, HCl and aluminum or dilute H2SO4 and iron, another way is to convert it (or reduce it) to silver in the melt using sodium carbonate in the flux.

Silver will dissolve in dilute nitric acid, silver chloride will not dissolve in nitric acid.

Silver nitrate can be precipitated with HCl to form insoluble silver chloride (leaving nitric acid as the byproduct, if excess HCl used it would form a type of aqua regia, leaving some chloride in solution).

NaCl will also precipitate silver from a silver nitrate solution, leaving sodium nitrate as the byproduct.

Both of the above methods produce silver chloride which needs conversion back to metal before melting as described above.

Copper will cement silver from a silver nitrate solution, or replace the silver in solution, this gives us a powdered silver metal that can be washed and melted without much trouble or loss (the byproduct would be copper nitrate solution).

Silver chloride can be dissolved in a thiosulfate solution, it can be cemented out of solution with steel wool, or electrolysis used to recover silver. 

Silver chloride will also dissolve in an ammonia solution, if doing this you should acidify the solution to precipitate the silver from solution and make it safer, as the silver ammonium complex can be dangerous if dried.

Silver metal will not dissolve in thiosulfate or ammonia.


It sounds like you have the silver/ silver chloride separated from the plastic, but at this point you still have a good portion of your silver as a chloride, melting it at this point you could burn off a good portion of your silver as white smoke, to prevent loss of your silver you should to convert the silver chloride to silver metal before the melt, or use a flux with sodium carbonate Na2CO3 also called soda ash, or washing soda, in the flux melt to convert the silver chloride to silver during the melting process.

Edit to add thoughts.
Silver chloride AgCl does not dissolve in HCl (although with high concentration and heat you may put a tiny bit into solution as AgCl2, dilution will precipitate it out of solution, my thought here is that with using HCl to remove the Ag/AgCl form the plastic you could still have chucks of silver chloride (which could be a bit more difficult to convert to silver metal by the normal conversion methods that we normally use on powders, where exposure to each grain of the salt is needed).


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## ayu

Hey butcher, appreciate all your time and your writing details about AgCl. I know I should search and learn more from the forum. Though I took chemistry (and quantitative chem) at school long time ago, for the specific case in melting metal it will be my first time. I have to get my hand dirty first before I can get any sense from all theories and other people's experiences. 

Sure I will upload a picture how my stuff looks like later. As I don't have quantitative lab setup, so I have no way to find out what's the ratio of Ag/AgCl on the film. If their thickness is the same, the ratio will be 2:1. 

According to wiki, melting and boiling point for AgCl is 455C and 1547C; while for Ag is 962C and 2162C. When using a propane/Map-Pro torch, I assume when they are heated to above 1547C but below 2162C (i think it is hard to control temperature), AgCl will be completely vaporized. I believe liquid Ag can be vaporized too during AgCl boiling, just assume and hope the amount can be minimized before the boiling point 2162C. My plan is to do a direct melting and a wet method too. Find out what different mass is between them.

Will update here. Thank all advices from you guys.


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## goldsilverpro

butcher said:


> silver chloride if heated can decompose to silver and chlorine


I know there are websites that make this claim, but it's not true. I don't want to give anyone the false impression that all they have to do to decompose AgCl to Ag metal is to heat it - it won't work. In the CRC Handbook, it gives the boiling point of AgCl as 1550C. If it were going to decompose before that temperature, the CRC would have surely said so. I also read that someone in an old mining book on Google had experimented and concluded that AgCl will start vaporizing at about 600C (1112F). When you put a torch on AgCl, the copious white smoke coming off is AgCl. I have seen many incompetent melts that started off with just borax, silver powder, and some unconverted AgCl. Most were heated to at least 2000F (1093C). After being poured and cooled, there was always an intermediate unconverted AgCl layer between the flux and the silver bar (some AgCl had surely vaporized, though). To me, this proves that AgCl doesn't decompose with heat. It will melt at about 455C and then start vaporizing at about 600C.


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## 9kuuby9

goldsilverpro said:


> butcher said:
> 
> 
> 
> silver chloride if heated can decompose to silver and chlorine
> 
> 
> 
> I know there are websites that make this claim, but it's not true. I don't want to give anyone the false impression that all they have to do to decompose AgCl to Ag metal is to heat it - it won't work. In the CRC Handbook, it gives the boiling point of AgCl as 1550C. If it were going to decompose before that temperature, the CRC would have surely said so. I also read that someone in an old mining book on Google had experimented and concluded that AgCl will start vaporizing at about 600C (1112F). When you put a torch on AgCl, the copious white smoke coming off is AgCl. I have seen many incompetent melts that started off with just borax, silver powder, and some unconverted AgCl. Most were heated to at least 2000F (1093C). After being poured and cooled, there was always an intermediate unconverted AgCl layer between the flux and the silver bar (some AgCl had surely vaporized, though). To me, this proves that AgCl doesn't decompose with heat. It will melt at about 455C and then start vaporizing at about 600C.
Click to expand...


So if i'm correct from the information written above AgCl doesn't decompose at the temperature of "550°C", So incineration would have no effect on AgCl? 

How should we recover the Ag from AgCl? using the ammonium method?


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## butcher

GSP, 
Thank You for clarifying that point, that we cannot decompose the silver chloride to silver and chlorine by heating, I have read that statement several places, but never could find details of temperature or conditions that it might happen, I also never considered it as a replacement method to reduce silver chloride back to silver metal as we do in our recovery or refining processes. 

I assumed that decomposition of the silver chloride with heat back to silver and chlorine would be something like how light will reduce silver chloride (or other silver halides like bromide or iodide) back to metal, like what is used in photography, but what works for photography would not work in refining, or would be impractical for use in the refining process as you would not be able to thoroughly convert all of the silver chloride easily, only the crystal's on the outer surface exposed to light would convert back to metal with the majority of the powders or crystals of silver chloride left unconverted not exposed enough to light to complete the process.

I do know for fact heating silver chloride to melt it, much of the silver will be lost in the white fumes.

I also have read where gold or silver with chlorides involved are volatile even at the temperatures used to roast ore, so they will also be volatile if we are incinerating gold or silver powders with chloride salts involved, or we would have some loss of silver if we attempted to incinerate a silver chloride powder. 


How should we recover the Ag from AgCl?
Convert it back to silver metal.


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## 9kuuby9

The problem I'm having sounds as follows; I have completely leached MLCC powders which is like white sand that turns into mud when water is added. Together whit that sand I have lots of AgCl. So even If I tried to convert it I would still have Ag With the MLCC powders. And I don't know if something will go wrong if I did the usual AgCl conversion method. Which brings me to think that If I do convert it together with the MLCC powders Then I'll have Ag and powders, Incinerate to eliminate most of the Chlorides? and the wash thoroughly whit hot Distilled water washes to remove any residual Chlorides. And then Leach the sludge with HNO3 for Ag?

I might give it a try, Can someone give me a link to Harold's incinerating method? I really couldn't find it Via the usual search and the search engine on Steve's Website.

:mrgreen:


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## butcher

If you have silver chloride mixed with white sand, you can dissolve the silver chloride with ammonia, and then remove it from the sand, and filter the solution and precipitate the silver chloride back out of solution with HCl, (for safety sake acidify the silver diammine solution as soon as possible).

I think it takes a lot of ammonia to dissolve the silver chloride.

one thing I would look into doing is to try and separate as much of the silver chloride from the majority of the sand as I could by mechanical means.

if the sand particles are large enough a filter screen sometimes works to separate most of the larger particles from the finer powders like silver chloride (some times a little stirring and crushing with a glass rod to get the finer powder rinsed through the plastic screen.

Another thing to consider silver chloride is fluffy and will usually float around for a while when heated in a solution, while sand or heavier metals, salts or material will settle for the most part fairly fast, you can also try this to attempt to separate at least a portion of the silver chloride and sands, stirring the heated solution letting the sands settle and cypher off solution with the floating silver chloride powders ( a suction bulb tool that looks like a turkey baster tool works great for transferring liquids). 

The mechanical separation will transfer some of the finer sand.

The other option is to convert the silver chloride to metal, I would use one of the replacement methods (Iron and dilute H2SO4) or (aluminum and HCl) methods, I think these would work better with the contaminates you have, than the NaOH karo method which does not seem to work well with contaminates.

once silver chloride is converted back to metal in the powders and sands, they can be washed in a solution of NaOH and then rinsed well to remove the salt water, then dried crushed and incinerated to red hot, cooled and are now ready to use the dilute nitric to remove silver and or Palladium


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## 9kuuby9

Thank you for the explenation; butcher.

It really helps when someone else has a bigger light bulb then myself; great information emerges! :mrgreen:


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## butcher

Just another thought here, if you have palladium incinerating it can form palladium oxides it may or may not convert all of the palladium metal powders to oxides.

Palladium metal or powders will dissolve in dilute nitric acid or aqua regia.

Palladium oxide will not dissolve readily in dilute nitric acid or aqua regia.

Palladium metal will not dissolve in HCl (unless strong oxidizers are added).

Palladium oxide will dissolve in HCl.

In Hokes book we learn we can take a mix of palladium oxide and palladium and put them both into solution, by heating HCl and adding it to these powders, which will put the palladium oxide into solution (but not the palladium metal powder) then without filtering, we can add HNO3 and water to form aqua regia which will also put the palladium metal into solution.


Something to consider if you do have palladium in with these white sands, incinerating is very likely to oxidize at least some or all of the palladium, so if you use nitric after the incineration to dissolve the silver, you would be able to dissolve any palladium metal powders, but not the palladium oxide into that nitric solution, in this case one option would be to test the nitric solution for palladium, if it tested positive, then it will be very likely the remaining white sands would contain palladium oxide.

There can be different methods to recover metals, sometimes we have choices and need to make a decision of what approach would be best in our situation, to help us decide a good understanding of how these metals react in different situations or solutions helps us decide how we will approach the problem, this is where our education shines, and Hokes book, her getting acquainted experiments, and understanding what she teaches helps us to decide how to approach the problem, or how not to create a problem, or how to get out of the problems we create.

Someone else may have a different or even better idea of how to recover the metals from those white sands. Keep studying Hoke's book and you can come up with a better solution or method.


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## 9kuuby9

Your help and wise explanation is appreciated butcher! :mrgreen:


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## niteliteone

9kuuby9 said:


> Your help and wise explanation is appreciated butcher! :mrgreen:


Appreciated by many of us


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