I never filtered my silver nitrate solutions when I was recovering silver, even if I had traces of silver chloride (which I routinely had). I never processed silver for the purpose of refining it-----it was used for inquartation. Only when it was used in that fashion and recovered with copper did it get a final refining. Totally irrelevant in the scheme of things, but there was method to my madness.
I found that even if I missed my inquartation and the gold broke up in fine powder, all it took was a few hours of settling, far less time than filtering. I also didn't filter when I washed the collected cement silver. Only when I was ready to dry it did it see a filter. I'd simply wash it with tap water, allow it to settle, then decant. I'd do this until the wash water was clear (usually only three times or so). It took almost none of my time aside from siphoning the solution.
When the wash was clear, I'd siphon off the last wash, then get the entire lot of silver in a large buchner. At this point, it filters very well, so it takes no time to pull the remaining water out. At that point it would have shrunk considerably, and pulled cracks in the silver. I'd compress the entire lot with the butt end of a pestle, then wash down the funnel well to insure all the silver was collected.
This process shrinks the volume of the silver tremendously, making it much easier to handle. When the water was extracted to my satisfaction, I'd them dump the silver in a large evaporating dish, where it was force dried on a hot plate. The silver was then ready to be melted with flux (borax only-----no soda ash). The silver, once molten, was poured into a large cone mold, so the flux could be separated.
When cooled, the buttons were chipped free of flux, then re-melted and cast as anodes, ready for the parting cell. The fluxing operation removed anything that was unwanted aside from traces of copper, so if you have a trace of silver chloride, it is removed in that phase of the operation. No big deal, really.
I reprocessed all my flux, including it with low grade wastes when processing residues in my large furnace. The flux reduced any chloride present, with the resulting silver acting as a collector for higher values. In a sense, the process I developed worked to my advantage, because I needed a collector anyway.
You might keep this in mind if you see more refining in your future. The benefit is you don't waste valuable time screwing around with a few cents worth of silver chloride, and it pays huge dividends when you recover it by collecting traces of values from low grade waste materials that might, otherwise, be lost.
That's my story, and I'm stickin' to it!
Harold
