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- Feb 25, 2007
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goldsilverpro said:
It wasn't that large, although I don't recall exactly how large it was. Were it not for notes I provided to the buyer of the refining business, I'd not even have the information at hand that determined the acid consumption. My guess would be that the cell held about 2½ gallons, total. I was never very interested in silver----it was a necessary evil, so I ran it.
Fact is, the amount I'd start with would consume almost the entire amount of silver, but not quite. I'd heat until there was no more action, then add a tiny amount of acid until I was satisfied with the traces of silver remaining, and the pH was acceptable. All of it went in the cell, including the undissolved bits of silver, which was just crystal from a previous refining. I think the 100 ounces/gallon is actually quite accurate.
When I first started refining, I purchased some reagent grade nitric, but ended up using it almost expressly for making critical solutions. The nitric I was purchasing appeared to be of high quality, so I, like you, used tech grade with excellent results. I watched for the formation of silver chloride when making electrolyte, but that was never an issue. I, of course, used distilled water.
Absolutely! While I'm not a chemist, one of the things I've read about is the hydronium ion. When you introduce nitric to silver, you find that it does very little work. Even when heated, it doesn't attack the silver with gusto. Add the slightest amount of water and all of that changes. My total volume of silver nitrate/water was held to about a half gallon while being produced, but, of course, was diluted for the cell. If I allowed my solution to cool, it immediately grew silver nitrate crystals.
It's been so long now that I don't have a clear memory of the things I'd experience, but one thing I seem to recall is that what little fuming I got was slow to leave the beaker. Fact is, I used the presence, or lack thereof, of brown fumes in the beaker to help identify when there was no further action. Like you, I have no clue if what I did was helpful, or not, but it did help keep the solution from getting contaminated from outside sources. I even kept my silver cell covered to exclude any dust that might settle.
I fully agree. Considering I was the only person to use my equipment, I was all too aware of the losses one experiences in refining. It's the reason my fume hood had a filter, which, for the most part, collected the majority of values that were lost from the vessels. While the amount of gold recovered from the hood wasn't large, as compared to the volume of gold that was processed, I recovered no less than eight ounces about every other year, and that was strictly from cleaning out the hood, that did not include the filters that were changed on a regular basis. You'd have to see how the hood was built to have this make sense. I had built a chamber for such material to accumulate, secure in the knowledge that there were losses. I should also comment that my hood was built entirely of asbestos, and was used for incinerating polishing wastes and filters from jeweler's benches. I have no doubt that some of the losses were from dusting in incineration, not just vapors.
Yeah, that's what I was alluding to. Somewhere in my library, all of which is in boxes aside from the odd book, I have something that discusses that very thing. Given enough time, I'll finish the house I'm building and unload the boxes.
I did a search a while ago to see if I could find books and other information pertaining to refining, but came up only with the loose-leaf you and I discussed some time ago, the one about the seminar in California. Couldn't even find my two copies of Hoke's book! We have a huge amount in storage----and I'm not up to spending enough time to sort through all of it at this point.
Harold
