[NewCandle] Quick update on my silver displacement experiments

[Nick Reiter]

Hi Keith,

Great dendrites, man!  tres cool.

I wonder if the black material is a reaction product of the silver nitrate with alloy components in the Al.  Do you have an assay of the aluminum alloy, or an idea of the grade?  Is it the same stock as you sent me a while back?  If so, you might be able to pick out a culpret from there - I dont recall 100% but I think there may have been some Fe and Mg going on.

Also, you use the term electrode - were you supplying outside current, or is this term covering the electrical currents and potentials presumably arising from the reaction at the surface?

n


> 
> Just a quick update on my on-going experiments with the
> silver/aluminum
> system. I fabricated some electrodes; aluminum rods ground
> into lozenge
> shapes, with a hole in the center to allow for support
> inside a test
> tube. They were mechanically polished with aluminum oxide
> sandpaper
> to a bright finish. The tubes contain .2M silver nitrate
> solution. This shot
> shows three
> tubes, all the same except for the size of the electrodes,
> after 8 days.
> 
> http://www.kpnconsulting.com/newcandle/download/k_silver1.jpg
> 
> The surface area of the electrode determines the reaction
> rate so
> you can see roughly what the surfaces looked like at
> different points
> in the 8 day timeframe. The black anode area coating
> eventually begins to
> break off
> along with gas being generated. Why this material tends to
> get stuck to
> the silver is a puzzle to me, outside of the obvious fact
> that
> it is getting stuck on the way to floating to the surface.
> Yet it seems to "crawl" around to other parts of
> the electrode?
> What is this stuff? I assume the gas in H2, but I
> haven't tested it
> yet. Clearly the available silver has either been depleted
> or
> enough aluminum is in solution to start a competing
> reaction
> to the silver displacement.