I believe you should be able to fire the black purifiers in an oxygen rich atmosphere (plain air), and the carbon should burn off. Otherwise you could remove it with something like carbon disulfide and maybe carbon tetrachloride, but then you would have a pretty smelly and toxic chemical that you would then have to get rid of as well.
Marshall Reid Harvey wrote: > 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 > http://www.purifier.com.np > > -- > The silver-list is a moderated forum for discussion of colloidal silver. > > Instructions for unsubscribing may be found at: http://silverlist.org > > To post, address your message to: [email protected] > > Silver-list archive: http://escribe.com/health/thesilverlist/index.html > > List maintainer: Mike Devour <[email protected]>
