Rick Miller said:
Thanks for the input, I have considered stripping with caustic. Even so far as drawing up ideas for an automatic unroller. After learning that 25 to 30 percent is lost in burning, may lean this way.
Of course, you don't want to use a solution strong enough and/or hot enough that will pulp the paper and create a big mess, which 20% caustic might do. In large scale production (10,000 pounds per load), we only used a 3-4% NaOH solution for film, but it ran at 200F for an hour. In my last refinery, I ran 10% caustic on film, in a tumbler, at about 140F for about 15 min. You might be a able to shred the paper in a fairly heavy duty paper shredder, which might also do the unrolling for you. That could solve the horrible thought of spending several years running one piece at a time. You could probably tumble shredded paper, in a solution, in a small portable plastic cement mixer, in batches. Another way is to use a small bucket, with holes in it, inside of a larger bucket containing the solution. The shredded paper is put into the smaller bucket and bobbed up and down, gently, ever so often.
I spent several years in a plant that ran a million pounds of film per month, but we NEVER ran paper. We (and, everybody else) sent the paper we got out for incineration. If I were to use chemicals, with paper, I would want to dissolve the silver halide, which NaOH won't do. NaOH attacks the emulsion and the silver, as an oxide, falls off with the emulsion, which is sort of like a gelatin. Sodium thiosulfate (photo hypo or fixer) is the only safe chemical which will dissolve the silver halide without removing the emulsion (the only other two possibilities are cyanide or ammonia). If you search for refining photo fixer on the forum, there should be a lot of info on how to recover the silver from the hypo. I always used an electrolytic cell, but the special type needed is quite expensive.
I foresee a TON of very small, lab-size experiments in your future. I would try anything and everything, including the caustic. By the way, what kind of paper is it. If it's for photos, whether color or B&W, it could run pretty good in Ag. If it's like old FAX paper, not nearly so good. If you know the manufacturer, and what it's used for, you might be able to find out the silver content, usually given in grams of silver per sq. meter, I think. I know Kodak used to publish that info for their products.
Another possibility. For about a year, I tumbled and stripped the emulsion/silver from film using a proprietary enzyme (protease type, I think). The solution contained about 45 to 60 grams/liter of baking soda (gave a pH of about 8.5, if I remember right) and about 110-120F. The tank was about 250-300 gallons and, every morning, I added only 400 ml of the high dollar liquid enzyme, which lasted all day and worked great. Very safe solution. The only problem was that it smelled like an outhouse. I've always been curious as whether a septic tank enzyme, like Rid-X, might work. Worth a small test in about a 250 ml beaker.
Were it mine, I would probably play with it for awhile and end up burning it.
Where in SW MO? My home town is Nevada, MO. I just moved to Arkansas from there couple of years ago.
Good luck!