Hi Reid, I'm not chemistry minded but you said "Feel free to speculate" so I'll run off at the mouth for a while. If you want "to gain capacity to saturate with AgNO3" I believe that "OLE BOB" posted to the list that the HVAC method of production introduced NO2 and NO3 into the CS solution. I guess I don't understand why you want to make silver nitrate - AgNO3. Then you go on to say that you want to "burn off the nitrate." Now I'm really confused.
I would think that you would just mix the powdered clay with CS instead of water, fire it and be done with it. I don't understand the idea of burning sawdust and clogging up the pores with carbon. I also don't understand the need to make NO3 and then try to burn it off. Are you dissolving silver in acid to get a higher concentration or something? The melting point of silver is 962C. If you are firing at 475C you should be okay unless the clay has lead or tin in it. My expertise in ceramics is a few classes in high school 30 years ago so if I sound like a fool that is why. Best regards, Andy (^_^) From: Reid Harvey Silver Friends, As some of you may know I work with ceramic water filters that are saturated with CS. Now I want to gain capacity to saturate with AgNO3, and I'm hoping that some of those who are chemistry minded may be able to guide me. Specifically I want to better understand how to burn off the nitrate. Following I explain a problem I have, and I'd be grateful for a response on this. What I have done in the past is to saturate the fired purifiers with the silver nitrate, then place these in a kiln and fire to the first visible red. I've done this in darkness so as to better judge this, the temperature around 475C. Then I reach into the kiln with tongs, place the purifiers in a bucket and cover with sawdust and a lid. The sawdust begins burning and the combustion, seeking oxygen, pulls some of this out of the purifier as NO3. Thus metalic metal remains, probably bonded to the ceramic. (Extraneous nitrates that may remain are flushed out with the first water put through the purifiers.) The problem is that the heavy oxidation implicit forces a lot of carbon into the pores, these having been vacated by the oxygen, so the purifiers turn black. My fear is that prospective purifier users will be put off by the blackness. So here are my *QUESTIONS:* Do I even need the the oxidation in the first place? If so, can I minimize the oxidation, in such a way as to pull out the nitrate, without forcing in the carbon? (Feel free to speculate.) At what temperature will I have gone too high, burning off the silver? I am looking for simple answers that will allay the need to determine these points with a lot of testing. Thanks! Reid <A HREF="http://www.purifier.com.np/";>http://www.purifier.com.np</A>
