# Silver from X-ray film



## crazyboy (May 11, 2008)

My friend and I are amateur chemists and we wouldn't normally have an interest in precious metal recovery but my friend's mom works at a veterinary hospital and they still use X-ray films as opposed to digital methods. He can get about 20-30 X-ray films per DAY and those things weigh a lot. I have heard silver can be extracted from films any tip?



BTW we have the following chemicals that may prove useful:

98% sulfuric acid
70%nitric acid
sodium hydroxide prills
boric acid

etc. We have tons more but I don't think they would be of any use.


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## goldsilverpro (May 11, 2008)

A average pound of standard rare earth x-ray film runs about .1 tr.oz, or $1.68 of silver, @ a $16.80 market. The range is probably from $1.00 to $1.80. The black on the film is the silver. The blacker, the better.

For this purpose, the only thing of value in your list is sodium hydroxide. However, its use is dangerous. I would suggest you read Harold's recent post on its dangers, before you even begin to consider it.
http://goldrefiningforum.com/phpBB3/viewtopic.php?t=2452&start=15


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## Platdigger (May 11, 2008)

OK Chris, what would you suggest?

Dilute nitric?

Sodium thiosulfate?

Other?

btw....Happy Mothers Day! To any Moms that may be on here....
Randy


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## goldsilverpro (May 11, 2008)

Bleach or about 8 to 10% HCl, by volume, will form AgCl, which can be converted to Ag. Dilute nitric can be used. 

No matter what you use, don't plan on profiting from doing it. The Ag is low, the waste is high. The film sheets stick together, when wet, unless you shred them.

The pros either use a enzyme/baking soda or a 4% to 5% caustic soda solution at about 200 deg F. The gelatin and the silver come off the plastic and form a sludge. The sludge is filtered, rinsed, incinerated (the stinkingest stuff I've ever smelled - probably very toxic), and then melted.


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## goldsilverpro (May 17, 2008)

I might also discuss the use of hypo - sodium thiosulfate. It doesn't dissolve silver metal - only silver halides - you have to first convert the black silver to silver chlodide, with bleach, ferric chloride, and/or HCl. Then, the next problem is to remove the silver from the hypo solution. This is normally done electrolytically with a rotating cathode. You could use zinc but it contaminates the silver. You could use steel wool but you will always end up losing some silver. Plus, it's a mess.

All in all, it's best not to use hypo, even though you'll find unknowledgeable people recommending it.


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## crazyboy (May 17, 2008)

Well we got a bunch of X-ray films and cut them up so they fit in a five gallon bucket. Then we added enough bleach to cover them and let it sit after a day or two the once black/gray slides turned a clear blue. The films were removed and the liquid poured into several containers white silver chloride immediately began to settle and we decanted. Unfortunately we realized we didn't have filter so we couldn't really collect the silver chloride or wash it so the conversion got messed up. I will repeat but I will use the sulfuric acid/metal conversion posted by lasersteve rather then the annoying hydroxide/glucose one.


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## Anonymous (Jun 6, 2008)

I'm planning on trying something similar. About how much silver chloride do you think you got out of the 5 gallon full bucket of film?


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## goldsilverpro (Jun 6, 2008)

I assume you're doing this purely for academic interest. You certainly won't make any money doing it.


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## markqf1 (Jun 6, 2008)

From what I've been able to read, there worth about 4 cents apiece.

Mark


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## goldsilverpro (Jun 6, 2008)

Maybe a little more, but not much.


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## Shecker (Jun 15, 2008)

This is a little trick I learned when doing a lot of film from x-rays. The celluloid covering on the film can be removed by a dilute solution of sodium hypochlorite allowing for the silver to washed off. The only problem with it was the NaOCl solution would get saturated with cellulose and cease to work.
A proteolytic enzyme will also remove the cellulose.

Randy in Gunnison


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## crazyboy (Jun 15, 2008)

Shecker said:


> This is a little trick I learned when doing a lot of film from x-rays. The celluloid covering on the film can be removed by a dilute solution of sodium hypochlorite allowing for the silver to washed off. The only problem with it was the NaOCl solution would get saturated with cellulose and cease to work.
> A proteolytic enzyme will also remove the cellulose.
> 
> Randy in Gunnison



This method was mentioned although I noticed bleach would stop working after awhile I never knew why. Everything would be going fine then it would stop and another half gallon of bleach would strip the rest of like magic. 

There is a subject similar to this on science madness a member striped a lot of silver chloride of X-ray films then dissolved it in sodium thiosulfate solution which he mixed with NaOH and glucose.


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## Juan Manuel Arcos Frank (Sep 3, 2008)

Guys:

Why do not you take a look at my recent post about silver recovery from radiographies?..it is in the process index.Good Luck.

Manuel


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## Ignatz61 (Nov 16, 2008)

OK,
I stripped a bunch of photoghraphic film with bleach. The black came off and left nice clear plastic.
I now have a grey liquid with clumps of white (looks like egg whites when poached.) Can I filter the cumps out? I am assuming they are not the AgCl.
I watched Steve's video converting the AgCl to Ag with a pice of copper and a pice of iron. But that was a Nitric solution. Will the same thing work for the bleach solution I have?
If not what is the best way to convert this to silver?
thanks,
john


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## Juan Manuel Arcos Frank (Nov 18, 2008)

John:

The grey powder that you have got is silver chloride (AgCl) with pure silver,this is the problem of this process and you have to refine the powder.Try Steve`s process to convert AgCl to silver,then you will have to refine all the powder with nitric acid process.

Better than this use the oxalic process,it is right here in the forum and you will get pure silver easily and fast.

Have a nice day

Manuel


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## lazersteve (Nov 18, 2008)

John and Juan,

The two silver reactions demonstrated on my website are focused on silver recovered from gold and silver refining waste not from photographic waste solutions.

The silver produced by any cementing method will not be 'pure'. For truly pure silver you will have to cast anodes and electrolytically part the silver.

This cemented silver will work great for inquarting karat gold as is.

Even if you do not part the cemented silver, its purity is very high (>98%) with proper washing techniques.

As an added bonus with gold and silver refining wastes, the copper nitrate formed in the silver cementing process can be recycled back into nitric acid or used 'as is' in the parting of sterling silver to produce extremely high purity silver, then recycled back into nitric acid.

When working with Silver Oxalate be sure to practice excellent safety habits as it can be explosive when heated. 

Oxalic Acid and Oxalate compounds are typically toxic. 

Here's an MSDS on Oxalic Acid that specifically mentions silver oxalate and it's hazards in the 'Stability and Reactivity' section..

Oxalic Acid MSDS

Steve


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## Juan Manuel Arcos Frank (Nov 18, 2008)

Steve:

All I know about the recovery of gold I have learned from you,for you all my admiration,respect and recognition and without wishing to contradict you I must say that the oxalic process is the best for silver film recovery.The process is described step by step in the section "Chemical Process" (titled "Film silver recover,a new process").

Sending you a big hug.

Have a nice day.

Manuel


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## lazersteve (Nov 18, 2008)

Jaun,

I know next to nothing about silver recovery from photographic films.

The oxalic process for silver films you promote sounds good to me.

I just wanted to stress the importance of safety to the members using any recovery/refining process.

Please don't take offense at this or any of my previous comments. I genuinely feel you have made some very good contributions to the forum.

Steve


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## Juan Manuel Arcos Frank (Nov 18, 2008)

I am with you,Steve,safety is very important in all our process.You are the greatest,you have posted more than anyone,I have read all your posts and I have never seen an offense yours.

Best regards

Manuel


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## Ignatz61 (Nov 18, 2008)

Juan,
I found a boat cleaner that has Oxalic acid in it but also phosforic sp?acid will that screw things up? I can't find straight oxaclic acid. 

I tried the boat cleaner on a small batch, it stripped them leaving a white cloud. I'll re-read your post on the process.
john


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## qst42know (Nov 18, 2008)

Oxalic acid is sold as one type of wood bleach. Hardware stores that sell woodworking, refinishing supplies should carry it as well as online. It definitely removes iron stains from oak wood. I think I read some where phosphoric is bad for your glassware.


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## Juan Manuel Arcos Frank (Nov 20, 2008)

Ignatz61:

You need pure oxalic acid.gst42know is right,oxalic acid is a common product.Please,observe how to handle pure oxalic acid.You have to disssolve it at 5% (w or v).

Regards.

Manuel


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