I can remember my first experience of observing a fire created by exothermic chemical reaction using KMnO 4 (potassium permanganate) , sugar, and acid during my after-school Science Club in Junior High School. Little did I know then that it would become my primary “Firecraft – Chemical Category” demonstration.
Typically, most chemical exothermic reactions involve some kind of liquid to initiate the reaction process. Although there are many chemical combinations to create a KMnO 4 fire, to my amazement, there is a fire method that does not require a liquid element in the equation. When mixed with sugar in a 1:1 ratio (a pile of each element about a quarter size in diameter) and mixed, you can lay a knife blade on it’s side or use a flat rock on top of the pile and press down firmly and begin rapid short strokes forward and backward. You will begin to hear small “pops” at some point the combination of heat by friction combined with the mixed chemicals will ignite. This typically produces sparks and embers that can be pushed together and coaxed into a flame using fine dry tinder layed next to the grinding site in ready position. Or sometimes, when technique and conditions are right, it may just erupt into a flame on it’s own as shown in the photo.
Since “9/11″ pyro-related chemicals have become restricted and more difficult to obtain. Potassium permanganate is a chemical oxidizing agent that is used for medicinal purposes and water purification and may be found at pharmacies and veterinarian supplies. It is also used to remove iron from water sources and can be found at chemical supply houses. It would be a good item to carry in portable first aid kits.
Should you decide to pursue this fire method, take care to stay upwind from the fumes. When using liquids for a reaction, it may take a little time to react, so don’t walk away from your experiment or abandon the set-up until you see a reaction and be sure to disassemble it altogether when finished. Potassium permanganate will stain deep magenta when moistened, so be thorough when cleaning up.