On Wed, 8 Jul 2020 12:15:21 -0400 Gene Heskett <ghesk...@shentel.net> wrote:
> On Monday 06 July 2020 00:43:30 Chris Albertson wrote: > > > On Sun, Jul 5, 2020 at 3:33 AM andy pugh <bodge...@gmail.com> wrote: > > > You say this a lot, but I have never heard anyone else say it. What > > > is your source? > > > > THis might be a "Chemistry 101" question. It should be easy enough to > > figure out except that I last studied this stuff in the last 1970s > > > > We all know that burning carbon produces a lot of heat. The chemical > > equation is > > C + O2 --> CO2 -394 kJ / mole > > > > The corresponding equation of aluminum is > > 4Al + 3O2 --> 2Al2O3 -1676 kJ/mole > > Aluminum produces more heat per mole than carbon and also more heat > > per gram than carbon. It would make good fuel except for combustion > > stops once the oxide layer is formed. > > > > Next, I looked up the specific heat of aluminum. It is very close to > > 1.0 kJ / (Kg K). So it only takes 1 Joule to heat one gram of > > aluminum one degree K. > > > > So there is plenty of energy and the metal is also easy to heat. But > > what we don't know is the fraction of aluminum that is oxidized. You > > could figure this out if you had a good enough scale and could collect > > all the chips. We could see how much mass the chips gained from the > > added oxygen. > > Difficult to do since the chips would have to be collected in an inert > atmosphere, ... If you want to avoid oxidation you could use inert gas, maybe nitrogen or co2 as then welding? _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
