Experiment 38: Iron Thermite!

After years of anticipation, I finally succeeded in making iron thermite, the king of infernos!  I used the aluminum powder from Experiment 35: Ball Mill & Aluminum Powder for Thermite and the iron (III) oxide from Experiment 37: Making Iron (III) Oxide for Thermite mixed intimately in a 1:3 mass ratio.  The resulting mixture was a somewhat golden color and had the consistency of flour.  I placed the powder in a depression dug in a pan of sand and lit it with a 2" magnesium ribbon.  The reaction exceeded my wildest expectations - it was an utterly brilliant ball of orange flame, totally engulfing the pan with its furious power.  Check out the video below for footage of the event:

Also, I have now started a Summer of Thermite playlist on YouTube, so be sure to subscribe to my blog by email or to my channel via YouTube to keep up with these firey experiments.  I plan on doing many more reactions similar to this one.

After the slag cooled, I removed it from the sand and broke it into fine pieces using a hammer.  For the most part, it was bubble-filled glassy alumina that easily fractured.  In some pieces, I found small blobs of iron produced by the reaction.  I cleaned the black oxide off the pieces of iron using vinegar and then swished them around with sand to abrade off other surface contaminants.  After weight the resulting product, I was absolutely astonished to find out that I had only recovered 16 grams of iron from the reaction!  Without even calculating anything, that is a terrible yield, considering I converted over 200 grams of iron in my iron (III) oxid
e producttion.  But since I like chemistry, I did some simple stoichiometry to reveal that starting with 322 grams iron (III) oxide, the theoretical yield would be 225 grams iron metal, so I got a 7% yield.  I believe most of my iron flew up during the reaction and rained down to earth as tiny iron droplets.  Honestly, though, the yield is of little concern to me considering how exciting the reaction was.  :)