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.

 

[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

 

[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.

 

[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.

 

[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

 

[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.

 

[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

 

[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

 

[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.

 

[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 .

 

[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.

 

[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

 

[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

 

[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.

 

[Harold_V]

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

 

[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

 

[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

 

[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.

 

[Harold_V]

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

 

[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