What happens when you mix rust and aluminum?

It is called thermite and as the previous answer indicated it burns ferociously reaching temperatures of over 2500 C. Aluminum with a variety of metal oxides are also thermites. Copper and manganese work really well. read more

Nothing! But if the rust and aluminum are powedered and wll mixed and you have something that can be used to ignite it, such as a strip of magnesium, a reaction will start that gets very, very hot. Aluminum has a higher affinity for oxygen than iron does and ‘steals’ it from the iron. The result is aluminum oxide and molten iron. read more

One responder commented, "If you add enough aluminum powder in a full load of concrete, eventually, there'll be enough gas to cause the mix to expand, and eventually the fresh concrete spills out of the drum. read more

Quick explanation of thermite: A mixture of iron oxide Fe2O3 (rust) and aluminum powder. When it is ignited the aluminum powder reacts with the O3 part of the rust in a highly exothermic reaction, the resulting product is molten iron. Thermite is commonly used in welding, because the molten iron has the ability to seep into cracks in metal. read more