Thermite
Thermite is a pyrotechnnic composition of metal powder and metal oxide. When ignited by heat or a chemical reaction, thermite will under go a reduction-oxidation process in which it produces heat. There are many forms of thermite, and most are not explosive, though nearly all create bursts of high temperature. Generally, thermite burns at around 2,200 °C, or 3,990 °F.
There are many kinds of thermites. Fuels include aluminum, magnesium, titanium, zinc, silicon, and boron, in which the most common is alumium because of its high boiling point and low cost. Oxidizers include bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide. Most forms of rust can be considered iron(III) oxide, which is why it is also common in making thermite.
The thermite reaction was discovered in 1893 by the German chemist Hans Goldschmidt, who obtained a patent for his process. Nowadays, thermite is often found in thermite welding, such as when welding railroad tracks. Thermite is also used in metal refining, disabling munitions, and in incendiary weapons.
Dependencies
- Aluminum, magnesium, titanium, zinc, silicon, and boron, in which the most common is alumium because of its high boiling point and low cost.
- Magnesium or a Sparkler
- Water
- Bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, or lead(II,IV) oxide[1].
Production Method
Thermite is highly flammable and will produce temperatures high enough to melt metal. Do not attempt making this in vicinity of at least four meters[2] (13.1 feet) of anything flammable or metals with low melting points, such as lead, tin, cadmium, or zinc; it will ignite.
Precautions
Alway use a ceramic container to hold the thermite. Plastic will burn and produce toxic fumes, and metal will likely melt and be unable to hold the thermite. Ensure that the container has a high melting point of at least 2,200 °C, or 3,990 °F.
There is no guarantee that the container will not break from the heat. Stand back when you ignite the thermite in case the container does actually break.
- Welding masks or glasses are recommended. The former is better, as it will protect your face from the potential UV radiation emitted while it burns. If you don't have either of those things, a pair of the darkest sunglasses you can find, preferrably with full UV protection, is also good. Do not look at the flames without a welding mask or glasses.
- Heatproof gloves and fireproof aprons are also recommended. The apron should cover your whole body.
- Keep your safety gear on at all times.
- Wear closed-toe shoes and pants and clothes that will cover any exposed skin. This is important because burning clothes are extremely hard to remove and will cause servere burns, in which case you will probably die.
Ingredients
Find a ceramic container. Two or more is better.
Get a propane torch or stick lighter.
Get some powdered iron oxide (rust), aluminum powder, and a strip of magnesium. The rust needs to be finely powdered to react with the alumium. The magnesium should be thin to easily burn and should be at least 6.5cm (2 inches) long. A longer strip will allow more time to step back. If magnesium is unavaliable, you can find sparklers and they may also work. Replace the iron oxide with copper oxide for an explosion. The alumium powder should not be oxidized.
The iron oxide and alumium powder should be in a weight ratio of 3 grams of iron oxide to 1 gram of alumium powder.
Grinding up the metals manually is somewhat dangerous. Already powered materials are preferred. Alumium powder can be found in paint stores or an Etch-a-Sketch.
Preparation
Dry out the iron oxide in an oven or over a Bunsen burner. Set the oven to around 93 °C or 200 °F for 1 hour. If you're using a bunsen burner, place the iron oxide on an evaporating dish over the flame for 1 hour. Remember to shut off the gas supply after the iron oxide has finished drying.
Allow the iron oxide to completely cool.
Mix the iron oxide and alumium powder together in a non-metal container, such as on a sheet of paper. Generally, the 3:1 ratio is a good rule of thumb to go by when making high amounts of thermite. Remember to never mix them in a metal container to prevent contamination of thermite.
Pour the resulting mixture in the ceramic container in the aforementioned. If you have a second ceramic container, put the one with the mixture into the second container. Do not use ice to control temperature. It will likely explode.
Deployment
Once the thermite reaction has started, the only way to stop it is with a high-pressure water jet from far away or extremely compressed air, and that may not even work. This is because the reaction produces its own oxygen, and therefore it will burn as long as the two powders are still there. If you are unsure if you want to continue, stop now.
Insert the magnesium strip or sparkler into the mixture. Light the magnesium strip with a propane torch or stick lighter. Do not use matches, as some of the phosphorous will drop into the thermite and it will burn at your face.
Wait for the reaction to end.
- ↑ Kosanke, K; Kosanke, B. J; Von Maltitz, I; Sturman, B; Shimizu, T; Wilson, M. A; Kubota, N; Jennings-White, C; Chapman, D (December 2004). Pyrotechnic Chemistry — Google Books. Journal of Pyrotechnics, Incorporated. ISBN 978-1-889526-15-7. Retrieved 23 May 2025.
- ↑ https://edu.rsc.org/experiments/the-thermite-reaction-between-aluminium-and-ironiii-oxide/724.article