I do not know much chemistry, or even if its some reaction happening... But the very coolest thing that I've done with thermite only uses about 100 grams of Fe3O4 + Al mix, poured into a brick hole, topped with pennies throughout the mixture. The pennies cause explosions like eruptions from a volcano! It's pretty damn cool to do and I highly recommend it (I'm not responsible for burned property or personal damages or loss of anything caused by you trying this) lol...
I really need a picture to show you, but it's really amazing and I'd love to know what the hell causes this violent eruption!