# Need Help Filtering Super Fine X-ray Silver



## jamiedrchiro (Aug 11, 2014)

Hi All. I have been experimenting with silver removal from some of my outdated xrays from my clinic. First they are silver halide films. I soaked in bleach to remove silver to form AgCl. My problems start here. The AgCl is soo fine, it is super difficult to filter and wash. 
I started out using gravity filtration, and then built a homemade vacuum filtration. The vacuum helps but literally takes 2-3 hours to to vacuum filter approximately 1/2 oz. of AgCl (not including wash). This is using a 7cm, medium 8 micron filter paper.
So, what I have been doing: settle, decant, add more H20, settle and decant, repeat. This helps but Im allowing 24 hours to settle. So it is very slow process. Just last night I tried GSP's wick filter. I am still unsure about it as of now. I also have some elemental silver I converted using NaOH and Syrup. It is harder than the chloride to filter . My main goal is to have high quality silver. But really how can you "wash" something that will just be soaking in the liquid for hours before the the liquid is removed thru filtration?

I have read and read, watched videos (thanks Lasersteve), but it seems like most silver produced in videos is granular and easily settles when agitated. My 1/2 oz Ag in solution of 1 quart of water will stay cloudy for well over 24 hours.

Does anyone have any suggestions? Would it be just as easy to incinerate before melting? 

Im not looking to make money at this, I am intrigued by the process and really enjoy studying and learning about the chemistry involved. 

Thanks in Advance


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## Barren Realms 007 (Aug 11, 2014)

Have you tried heating you solution to see if it will settle faster?


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## jamiedrchiro (Aug 11, 2014)

Thanks for the reply. 

Yes I have tried heating the solution. Most times after I decant, I add boiling hot water, stir and let it settle again for at least 24 hours.


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## Lou (Aug 11, 2014)

egg white?


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## jamiedrchiro (Aug 11, 2014)

Egg White??? I'm sorry, I do not know what you are referring too. 

Am I missing something?


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## Lou (Aug 11, 2014)

Egg white to flocculate the fines and clarify the solution if the pH is not so extreme as to denature the proteins.

Lou


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## jamiedrchiro (Aug 12, 2014)

Thanks Lou, I searched the forum for this (using egg whites as flocculating agent), I cannot find any posts showing/explaining how to do it. Can you point me in the right direction?

Also I played around with the wick filter setup a little more. Is it possible for some of the silver to be transferred via capillary action thru the wick and into the collecting vessel? Based on my understanding, it is not, but would like to hear from others.

Thanks


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## Lou (Aug 12, 2014)

Have you ever made an omelet?


and no, if the silver is in a zerovalent (that is, metallic state) the most it will do is infiltrate the pores of the wick and stay there as the liquid is drawn up.

May be easier to just make the whole kit and caboodle acidic, add in some coagulating agent (50 ppm) of aluminum chloride perhaps, then raise the pH until the aluminum brings it all down. We use that trick all the time.

Lou


PS...apparently works well on ponds too:

http://www.backyardaquaponics.com/forum/viewtopic.php?f=26&t=6907


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## jamiedrchiro (Aug 12, 2014)

Thanks Lou, Interesting posting about the eggs in ponds.

You learn something every day..


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## Juan Manuel Arcos Frank (Aug 18, 2014)

Jamiedrchiro:

LOL!!!!!!!!!!!!!!!!!!!!!!!!!...Have you ever heard about egg white´s flocculant properties?...LOL!!!.

Lou´s advice is wonderful and keep your eyes open for all what he says because he is the greatest chemist in this Forum.

You are in the right boat but in the wrong river,I mean,bleach is the right process,the way you are doing it is wrong,Why?...because your are invoking a very bad Demon...we all know his name:COLOID,so you are forming a silver chloride coloidal solution which never will precipitate.Lou sent you to the kitchen to prepare an omelet and it was OK,now you and me will make an exorcism to send COLOID Demon away:

First of all,you have to discharge the silver chloride coloidal solution by boiling it for 1.30 hrs,at least,then let it rest for a while until a white mud is formed,now you can process the white mud by Karo syrup,metallic replacement or Na2CO3 processes.


Bleach breaks gelatine in film emulsion,forming silver chloride is a mistake,so you need to add some NaOH to your bleach solution to prevent Cl2 production.One of our Brotherhood´s member has posted a patent about this process,for 1 Kg. of film:

Water 8.3 lt
NaOH 20 gr
Bleach 0.432 lt

the result is a black mud which settles down in a couple of hours,filter,dry,melt with Na2CO3 and you will get 0.999 nice white silver.

Well,he have defeated COLOID Demon and keep in mind that the best thing about Demons is to stay away from them and never ever invoke them.

If the going gets rough,please,let me know.

Kindest regards.

Manuel


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## butcher (Aug 18, 2014)

Juan Manuel Arcos Frank,
You deserve a good cigar after that post.


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## jamiedrchiro (Aug 19, 2014)

Juan thanks for the information. I thought I had rad about all the different ways to process silver from x rays. But I never heard of a solution of bleach and lye together. Is there a thread where it is discussed in detail. I like details. 

Also, Juan, I thought you were oxalic acid all the way? I have some oxalic acid and would like to try using it, but I do not have a suitable container for the acid and x rays. 

Thanks for all the help.


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## MarcoP (Aug 19, 2014)

Such a great post, hope you enjoyed your well deserved cigar!

I'm learning my way through so forgive me if I'm wrong about this but I'm really curious by nature and when I see 1/1000 precisions, rocks start tumbling in my head. Is the amount of caustic used taking account of Cl- coming from tap water?
Some concentration rises up to 1gr Cl-/L so we could end up with, just say in the worst case, 8gr Cl- per Kg of films ready to react back with Ag+ coming from halides?

I only hope I'm not far out of the path.


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## Juan Manuel Arcos Frank (Aug 25, 2014)

Sorry guys,I offer you an apology because I am late.let us see:

Butcher,My Dear Friend:Thanks for the big cigar,I hope we could together smoke one,with a big bottle of whisky and some pretty girls.I send you a big hug.

Jaimedrchiro:Here is the patent,so take a look.Oxalic process will work well but it needs high temperature and stainless steel vessel,try bleach process,it works at room temperature.

MarcoP:Chlorine gas(Cl2) only exists in acidic condition,so to prevent forming it you need an alkaline condition,that is why you have to add some sodium hydroxide to keep pH high.The mud formed is a mixture of organic matter and silver,no silver chloride is formed.

Have a nice day

Manuel


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## jamiedrchiro (Sep 2, 2014)

Juan, Thank you very much for the link. I read and tried out a test batch to make sure it would work properly. It did not turn out very well. Here is what I did, using the numbers given in the patent link (just used a smaller batch). I used 1 pint water, 1/2 pint 8.25% bleach and 3 grams NaOH. Added solution to a 1 quart mason jar and placed 2 film strips 1inch wide by 8 inches long into solution. Waited 15 minutes and well nothing. Tried rubbing, and stirring also. Then waited 3 hours and checked again. The solution weakened the emulsion, but was not going to come off easily. So I gave up. 

Has anyone used this process before with success? Does the solution need constant agitation? Once again any help is appreciated. 

Juan, by the way, I really enjoy reading your posts. I am sure you are a great story teller.


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## rickbb (Sep 2, 2014)

The batches of x-ray film I've done needed some heat, I heated the solution to between 150F and 170F and the emulsion came off in a few minutes. 

Some agitation helps as well to keep the film from sticking to each other.


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## dannlee (Sep 2, 2014)

Just a factoid: There is hydroxide(s) in laundry bleach as preservative(s), molar balanced I'm told - so diluting laundry bleach (or cheap bathroom cleanser to stretch number of uses) for cleaning chores etc. should be only as needed and not in days/weeks advance as the chlorine will have dissipated when going back to use it later on...


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## Juan Manuel Arcos Frank (Sep 5, 2014)

Sorry,guys...I am late again.

First,I was working very hard in Mexico City processing 4000 lt of spent fixer.Second,when I was in my way to home,a nice lady,who was my girlfriend when we were young, crossed my way and I spent 3 days with her..until she walked away because her husband was really upset.Finally,on September 01 it was my 50 th birthday and I got drunk.I offer,all of you guys,an apology.

Jamiedrchiro:

Look,I use 14% sodium hypochlorite and a washing machine because good agitation is needed.Probably,you are using a dilute solution of sodium hypochlorite.A year ago,I processed some X ray films from jet´s turbine blades,these films gave some problems because emulsion was very thick so I had to process them twice but it was a great...silver yields were pretty high.

My advice to you is to use 14% sodium hypochlorite and good agitation...even by hand,with a wood rod.

Keep us posted about your progress.

Kindest regards.

Manuel


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