Explosives that changed the world

Jul 21, 2008 13:30 GMT  ·  By

Similar to most of the chemical explosives available today, dynamite is a mix of compounds that burns rapidly when ignited. It is based on a chemical substance known as nitroglycerin, a powerful liquid explosive, extremely unstable to physical shock. To harness the potential of nitroglycerin without the downside of its well known instability, it is usually mixed with certain absorbent materials and is given the name dynamite, although currently it is rarely used for any applications at all.

Dynamite was originally invented by the famous Swedish chemist and engineer Alfred Nobel who at first used diatomaceous earth, or kieselguhr, to stabilize nitroglycerin. One year after the invention, Nobel patented it in England and Sweden and began selling dynamite under the name of 'Nobel's Blasting Powder'. Soon after, dynamite gained worldwide popularity due to its explosive power and for being as a safer alternative to gunpowder and nitroglycerin.

Dynamite basically consists of 75 percent nitroglycerin, 25 percent diatomaceous earth and a small amount of sodium carbonate. The mix is shaped, usually into a rod, and packed in paper before being commercialized. The problem with this design is that over time the nitroglycerin will start to 'sweat' out of the absorbent material, possibly forming pools in the storage area or crystals on the paper wrapping. Knowing the stability problems of nitroglycerin, this can potentially end in the explosion of the dynamite without the presence of a blasting cap.

Dynamite was primarily used in warfare and in the mining, quarrying or construction industries. However, due to the 'sweating' effect of old dynamite and the fact that it can also become unstable when frozen, it is now considered obsolete and is no longer used as explosive chemical.

Instead, TNT and other more stable compounds are preferred. There is a general belief that dynamite is TNT. In fact, TNT is a chemical substance known as trinitrotoluene while dynamite, as described in the upper paragraphs, is nitroglycerin stabilized with an absorbent. Furthermore, dynamite has an energy density of about 7.5 megajouls per kilogram, as compared to TNT which has a mere 4.6 megajouls per kilogram.