Silver in photographic paper
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Chumbawamba
Well-known member
Come on! This wasn't even a difficult search.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=7361&p=66841&hilit=photo+paper#p66841
Use the search feature!
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=7361&p=66841&hilit=photo+paper#p66841
Use the search feature!
Is it paper or is it film?
If lithographic film, the plastic is either .004" thick or .007" thick. Determine the thickness and find the silver content on my chart in the link above.
If it is paper, I have no idea. It surely depends on such variables as whether it is color or B & W. Maybe Manuel would know.
If lithographic film, the plastic is either .004" thick or .007" thick. Determine the thickness and find the silver content on my chart in the link above.
If it is paper, I have no idea. It surely depends on such variables as whether it is color or B & W. Maybe Manuel would know.
According to this Kodak document, you can call 716-477-3194 and Kodak will tell you the silver content of specific papers, per 1000 square feet - middle column, page 3.
http://www.kodak.com/eknec/documents/f9/0900688a800f80f9/J210ENG.pdf
In searching, I found a lot of sites that said the silver content of papers was 1.5 grams/square meter, which is about 20, 8x10s. I don't know whether this was for color or B&W. I found some indication that color paper had less silver than B&W.
http://www.kodak.com/eknec/documents/f9/0900688a800f80f9/J210ENG.pdf
In searching, I found a lot of sites that said the silver content of papers was 1.5 grams/square meter, which is about 20, 8x10s. I don't know whether this was for color or B&W. I found some indication that color paper had less silver than B&W.
Juan Manuel Arcos Frank
Well-known member
Yes Sir,color paper contains less silver than B/W.
Silver content varies from brands,including papers of same brand,as Kodak,i.e. there is a different silver content between Kodak Royal and Kodak Supra papers,both are color papers.
It is easy to know how many silver is present in 1 kilo of papel,just weight it and dip that kilo onto a fixer(sodium/ammonium thiosulphate) solution and in 3 minutes you will dissolve all silver,then you can test silver content using many techniques,among copper wire,silver strips testing paper,sodium sulphide,zinc/hydrochloric acid and so for.
You can process all that hundreds of pounds dissolving them in fixer and then recovery silver with sodium sulphide,zinc/hydrochloric acid or electrolytc process.
Hope it helps.
Regards.
Manuel
Silver content varies from brands,including papers of same brand,as Kodak,i.e. there is a different silver content between Kodak Royal and Kodak Supra papers,both are color papers.
It is easy to know how many silver is present in 1 kilo of papel,just weight it and dip that kilo onto a fixer(sodium/ammonium thiosulphate) solution and in 3 minutes you will dissolve all silver,then you can test silver content using many techniques,among copper wire,silver strips testing paper,sodium sulphide,zinc/hydrochloric acid and so for.
You can process all that hundreds of pounds dissolving them in fixer and then recovery silver with sodium sulphide,zinc/hydrochloric acid or electrolytc process.
Hope it helps.
Regards.
Manuel
Speaking of fixer, I have a couple of the 5 gallon canisters that are used in in photo labs for recovering silver by digesting the steel wool that was in the canisters. I am curious to know what the process is to convert the rusty looking remains in these canisters to silver metal. Is there a thread on this topic? Any advice?
Juan Manuel Arcos Frank
Well-known member
Hard to know....if steel wool is almost complete then there is no silver...if canister is exhausted then all inside is a black mud which means that there is some silver.You can process it with nitric acid method using a NOx prevention system like H2O2,NaOH or urea scrubber.
Regards.
Manuel
Regards.
Manuel
Those steel wool canisters aren't easy to process without a furnace. In theory, these would be be run until completion and all of the steel wool has dissolved and cemented out an equivalent of silver. In practice, there is usually a mixture of undissolved steel wool, gray cemented silver, and silver sulfide. Often there is more steel wool than silver. Of the 1000s of canisters I've seen run or have run myself, I would guess that 50% of these contained from 0 - 1 oz of silver. This makes chemical processing a very poor choice unless they contain no steel wool. The standard method is to put the insides into a large crucible furnace with a lot of borax and soda ash along with several lengths of rebar. The rebar should be long enough to stick out of the furnace a foot or two. The iron in the rebar combines with the sulfur from the silver sulfide and enters the slag layer. The result, with proper amounts of fluxes and some know-how, can be a fairly pure silver.
Take a look ad whats on the inside of the canister. If it's nearly full of a rusty looking steel wool, it may not be worth running. At the other extreme, if there's little steel wool left and there is a lot of heavy black/gray sludge, it could be very good. Usually, it's somewhere in the middle.
If one operated these canisters as they should, they can work quite well. However, most x-ray technicians don't have the time or the inclination to mess with them. Usually, the canisters are changed routinely (every month or two) by a service that hooks up a new canister and takes the old one with them. They don't look at the insides to see if they are saturated. They just change them. You end up with a full gamut - those that have nothing but silver (and silver sulfide) to those with essentially no silver.
Take a look ad whats on the inside of the canister. If it's nearly full of a rusty looking steel wool, it may not be worth running. At the other extreme, if there's little steel wool left and there is a lot of heavy black/gray sludge, it could be very good. Usually, it's somewhere in the middle.
If one operated these canisters as they should, they can work quite well. However, most x-ray technicians don't have the time or the inclination to mess with them. Usually, the canisters are changed routinely (every month or two) by a service that hooks up a new canister and takes the old one with them. They don't look at the insides to see if they are saturated. They just change them. You end up with a full gamut - those that have nothing but silver (and silver sulfide) to those with essentially no silver.
Manuel,
Thanks, I'm familiar with that method and will try it. Gracias, mi Amigo!
goldsilverpro,,
Yes, the steel wool has been completely digested, I have had marginal success with firing in a furnace. I've got a nice, new furnace, molds, crucibles. Do you recommend grphite or will coated clay work as well? The melting flux is probably my only concern. I have the basic flux components. The rebar is a good idea. The furnace is a Vecella (sp) front loader.
I have heard mention that nitric acid can be reclaimed - Is NOx mixed with H2O or H2O2 and if so, how?
Thanks, I'm familiar with that method and will try it. Gracias, mi Amigo!
goldsilverpro,,
Yes, the steel wool has been completely digested, I have had marginal success with firing in a furnace. I've got a nice, new furnace, molds, crucibles. Do you recommend grphite or will coated clay work as well? The melting flux is probably my only concern. I have the basic flux components. The rebar is a good idea. The furnace is a Vecella (sp) front loader.
I have heard mention that nitric acid can be reclaimed - Is NOx mixed with H2O or H2O2 and if so, how?
I also have a Vcella furnace that I use as an assay furnace. An electric box furnace would definitely not be the best furnace to do this in. First of all, melting this material is messy. It is easy to get spills and an electric furnace is very prone to damage with spills. I, personally, do not like to melt anything but pure metals in an electric furnace. With a lot of fluxing, you can have problems with the elements and the refractory. Don't ruin your furnace. If I remember right, a re-build kit for the Vcella runs about $900. In my opinion, what you need for this is a workhorse, top-loading, gas-fired crucible furnace. If you do use the Vcella, do it in small batches and take care you don't overload the crucibles.
If most all of the material is silver without a bunch of undigested steel wool, you should probably try it chemically. Try small amounts until you get a workable process.
If most all of the material is silver without a bunch of undigested steel wool, you should probably try it chemically. Try small amounts until you get a workable process.
Yes, thanks for the advice!
I have a top loader, gas furnace, too. It seems to take a long time to get up to temp. patience... patience!!
This appears to contain a lot of oxide i.e. iron oxide, would it be recommended to get it up to temp and then shut it off and close up the ports including top to get a reducing atmosphere? I tried charcoal in prior attempts in a mix - it didn't seem to reduce the silver. In theory, the carbon creates co2 which consumes oxygen and reduces the oxide to metal. The paradox with the gas furnace seems to be that you can't get a reducing environment and maintain combustion of the gas.
Photographic paper would supply carbon to that type of silver recovery in a furnace. Maybe too much!
I have a top loader, gas furnace, too. It seems to take a long time to get up to temp. patience... patience!!
This appears to contain a lot of oxide i.e. iron oxide, would it be recommended to get it up to temp and then shut it off and close up the ports including top to get a reducing atmosphere? I tried charcoal in prior attempts in a mix - it didn't seem to reduce the silver. In theory, the carbon creates co2 which consumes oxygen and reduces the oxide to metal. The paradox with the gas furnace seems to be that you can't get a reducing environment and maintain combustion of the gas.
Photographic paper would supply carbon to that type of silver recovery in a furnace. Maybe too much!
Geowizard, trouble with metal oxide's in furnace, carbon burns off so how can you have too much, if removing oxide from the metals is your purpose? unless ash is of concern.
maybe using a cover crucible lid, with flux and carbon, may help in converting oxides in melt to metal, (muffle for your furnace ?), shield melt from oxygen introduced at burner, if furnace is feeding excess air you may be burning up all the carbon using air introduced at burner, and carbon is not extracting the oxide from metals, limiting air to burner may also help.
maybe using a cover crucible lid, with flux and carbon, may help in converting oxides in melt to metal, (muffle for your furnace ?), shield melt from oxygen introduced at burner, if furnace is feeding excess air you may be burning up all the carbon using air introduced at burner, and carbon is not extracting the oxide from metals, limiting air to burner may also help.
Absolutsecurity
Well-known member
I have two of these Silver ion exchange filters made by Silver Sure. One looks newish with clean looking steel wool in white fiber gauze roll (might very well be new) and the other cansiter was full of red liquid (rust right). Can you just do a hydrochloric digest on the steel wool and furnace whats is left after rinses? Or since I have limited access to a crucible furnace wait and do the steel rod method??
Just looking for the easy way as usual! LOL!!
Just looking for the easy way as usual! LOL!!
manorman
Well-known member
I have a few boxs of old unexposed glass photo plates, how would i recover the values? Im sure someone collects these but i have never found a buyer.
MIke
MIke
qst42know
Well-known member
geowizard said:
Carbon monoxide scavenges oxygen forming carbon dioxide but in this case the important reaction is iron rods scavenge the sulfides. This is much like a fire assay technique for dealing with sulfides. Excluding oxygen might not be beneficial in this case.
etack
Well-known member
manorman said:
Are they usable?
Eric
