On 30 Jul 2014 at 17:05, Dennis Miles via EV wrote: > Silicone dioxide is glass, and aluminum oxide is clay, which when > heated becomes ceramic, for example...
Maybe it's splitting hairs, but (even though I took freshman chem a LONG time ago) I don't know that I'd say "aluminum oxide is clay." If I'm not mistaken, potter's clay contains aluminum compounds (silicates). I think you can chemically extract Al2O3 from it. Maybe you could say that potter's clay CONTAINS aluminum oxide, but aluminum oxide isn't clay per se. I would further disagree with "Silicone dioxide is glass," for two reasons. First, as with clay, glass does CONTAIN silicon dioxide. However, it also contains other compounds, such as sodium carbonate and lime. And being a language stickler, I should also point out that the words "silicon" and "silicone" are not interchangeable. Silicone CONTAINS silicon, but silicone is not an element, nor does it occur in nature. It's a synthetic (man-made) chemical compound. There is no such critter as "silicone dioxide." To bring this back on topic, aluminum is not the best conductor, and aluminum oxide is a pretty poor one. Unfortunately making al requires a lot of energy to reduce the bauxite, and this high embedded energy means that Al is always in a big hurry to turn itself into aluminum oxide. To keep this from happening, you have to keep air away from it. In practice, you apply your NoAlOx or other grease within moments after you abrade aluminum terminals (and aluminum wire, if you're using it). In fact the instructions with at least one of those glops tells you to slather it on the (aluminum) wire, then wirebrush the wire with the goop already on it. As a side note, aluminum's high embedded energy and eagerness to oxidize also makes it potentially (pun not intended) useful to power EVs. In the past, EV projects have tried out aluminum-air batteries. (Unique Mobility teamed up with AlCan for one of them in the 1980s.) There are big problems with al-air, though. For one thing, they're primary (non-rechargeable) cells - in some ways more similar to fuel cells than to batteries. Thus, you don't recharge them, you replace them, or at least rebuild them in place. Also, al-air batteries aren't very efficient. They deliver only about 15% of the energy that went into refining the aluminum. I don't think that includes any energy use factors for transporting the alumnum to where the EVs would load it in, so that would make for a further efficiency hit. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
