A Comprehensive Guide to its Reactions, Applications, and Safety

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Introduction to Thermite

Thermite, a mixture of aluminum powder and iron or other metal oxide is known for its intense heat, has captivated the curiosity of scientists, engineers, and enthusiasts alike. Although most compounds are not explosive, thermite can be used to create a heat source in a controlled or uncontrolled manner. Due to the drastic reactivity difference between the atoms, when uncontrolled it can reach temperatures of over 2,500ºC.

When thermite is ignited, a chemical reaction occurs when the oxygen atoms separate from the metal oxide and attach to the aluminum atoms as aluminum forms stronger bonds with oxygen than iron. The products of the reaction are a stable aluminum oxide, iron (or other metal if a different metal oxide is used), and a large amount of heat.


Thermite was first discovered at the end of the 19th century by German chemist Hans Goldschmidt while attempting to refine metals without the use of carbon. It began to be used in welding shortly after.

Understanding Thermite Reactions: Science in Action

To fully appreciate thermite, we must first delve into the chemistry that powers its reactions. Thermite mixtures typically contain a metal oxide and a reducing agent, with the most common combination being iron oxide and aluminum powder. When ignited, the reducing agent steals oxygen from the metal oxide, producing intense heat and molten metal as a result. This exothermic reaction can reach temperatures of up to 4500°F (2500°C), making it an incredibly powerful source of energy.

Common Applications of Thermite

In an industrial context, thermite is used in a variety of welding applications, particular for welding very large sections of iron or steel. For example, thermite can be used for welding railroads in situ which can save time and money as it does not require bringing in more expensive equipment.

Thermite can also be used to purify the ores of other metals, however this is not a common use. For example, the so-called thermite process was used in the Manhattan Project to obtain pure uranium.

Thermite being used to weld rail road tracks.

Thermite being used to weld railroad tracks

BiSN Applications of Thermite

BiSN uses a thermite heater in our tools to melt the bismuth alloy that creates permanent, V0 gas tight seals in downhole applications. Through years of research, development and testing, engineers at BiSN have discovered a way of controlling the thermite reaction so that it is safe and predictable for commercial use.

BiSN’s team of scientists and technicians have been able to harness the power of thermite in a safe, predictable manner, making it perfectly safe for commercial use.

BiSN now creates its own custom, thermite crumbles to accommodate several environmental factors including length of burn, length of heater and temperature requirements. This allows BiSN tools to be used in different applications and environments including both on and offshore contexts.

Thermite heaters are used when working with our bismuth alloys for the following reasons:

  1. A large amount of energy is required to melt bismuth alloy
  2. The speed of the reaction once the thermite is triggered
  3. The ease of ignition from surface using BiSN’s developed triggering mechanism

How Does BiSN Safely Use Thermite?

BiSN has developed several thermite crumbles that can be safely used with different properties. These crumbles are densely packed into a heater element that does not allow the ignited thermite to escape or spray. The thermite is safely ignited through a developed triggering mechanism and the burn is completely controlled and contained.

How Does BiSN Safely Use Thermite?

Demonstration of BiSN's controlled thermite burn process

Future Development

BiSN is constantly innovating, bringing new thermite crumbles, heater designs, new alloys and applications through a cycle of research, development, and testing.

Currently BiSN engineers are in the last stages of testing a liquid thermite application that stands to remove the need for section milling altogether and revolutionise the industry.

Future Development

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