By Joni Goodman & Courtney Jolley Chipola Junior College Thermite Reactions A chemistry honors project By Joni Goodman & Courtney Jolley Chipola Junior College

What is a thermite reaction? A thermite reaction is an exothermic reaction in which aluminum metal and iron oxide react to form aluminum oxide and iron metal. It reaches very high temperatures and causes the metals to melt due to the heat reached.

The chemical equation for a thermite reaction is:

Uses for Thermite Reactions It is often used in welding for things such as railroad tracks. It can be used in weapons such as bombs and grenades as incendiary devices. It is used as an oxidizer with ammonium perchlorate to provide the thrust for the space shuttle. It has also been used to purify some ores of metals such as uranium.

A thermite reaction can be mixed and stored and be considered generally safe because it has such a high initial ignition requirement.

An example of a thermite reaction:

Another thermite reaction:

History of the Reaction Soon after metallic aluminum was first isolated, both Sainte-Claire Deville and Wöhler noted that, if mixed with oxides of certain metals and supplied with enough heat, it would melt the metals. In 1895, Dr. Hans Goldschmidt applied this process and discovered what we call the thermite reaction.           

Natural Occurrences of Thermite Reactions      On April 6, 1999, a fire occurred at a filling station in West Yorkshire during a road tanker delivery involving the operation of stage 1b vapor balancing equipment. It was when the HSL scientist noticed the combination of aluminum and rusty steel in the form of aluminum couplings and steel banding on the delivery hose, that incendive sparks from a thermite reaction were suspected.

In a recent incident at a chemical plant, two beds of titanium structured packing in a distillation tower ignited. Ignition occurred while a hand held battery powered grinder was in use as part of an inspection activity. Sparks formed when the grinder touched stainless steel or titanium are believed to have initiated a thermite reaction between the thin sheet titanium structured packing and a dried iron oxide layer that had accumulated on the packing surfaces.