Aluminothermic Technology

Existence of High-Tech Metal-Based Explosives

The best-known explosives are composed primarily of nitrogen, oxygen, carbon, and hydrogen. It's not well known that powerful explosives can be made entirely from metals and oxides of metals.

One of the critiques of theories that thermite was used to destroy the World Trade Center skyscrapers asserts that thermite preparations don't have sufficient explosive power to account for the observed features of the buildings' destruction. This criticism seems to be uninformed by knowledge of some of the aluminothermic preparations known to exist -- particularly those being researched for military applications.

Thermite demonstration

The typical classroom demonstration of the thermite reaction is very pyrotechnic and heat-producing, but is not explosive. The reason for this is that the reaction rate is too slow to cause the rapic increase in pressure characteristic of a detonation, or sharp explosion. It's not for lack of energy: the energy density of thermite (Al + Fe₂O₃) is comparable to TNT on a weight basis, and three times as dense on a volumetric basis.

In contrast to the slow-burning behavior of low-tech thermite preparations, various engineered forms of aluminothermic materials have explosive power resembling conventional high-explosives while retaining higher energy densities. ¹   One method of increasing the reaction rate is to finely mill the metallic powers and mix them thoroughly so as to increase the surface areas of the reaction zones. Other methods involve adding various compounds and elements to the mixture. Some additives are designed to stabilize the preparation so that it won't degrade or accidentally ignite.

A since-removed document posted on the Los Alamos National Laboratory website, under the heading Licensable Technologies, describes an aluminothermic material that has a fast reaction rate.

Enhanced Explosive Materials Using Nano-Particulate Metal Fuels

Summary:
Metal fluorocarbon mixtures have been recognized since World War II as highly reactive pyrotechnics. Their use as explosives, however, has, until recently, been limited due to the inherently low reaction rates of the metal particles with the fluorocarbon material. Scientists at Los Alamos National Laboratory have discovered that these slow reaction rates can be greatly enhanced by substituting nano-sized aluminum for the conventional micron-sized metal powders, enabling various applications heretofore not possible with metal fluorocarbon mixtures.

Nano-sized aluminum acts as a burning rate modifier. Its high surface area allows for fast chemical reactions enabling explosive, propellant, and pyrotechnic applications that could not previously be achieved using metal fluorocarbon mixtures. Additionally, nano-sized aluminum acts as a thickening agent, meaning that one can use a liquid fluorocarbon as part of the mixture. The liquid fluorocarbon completely coats the aluminum particles, while the mixture’s consistency remains suitable for use as explosive, propellant, and pyrotechnic fill material.

The nano-sized aluminum and fluorocarbon mixture has a high weight and energy density compared with standard explosives—-ideal for small and medium caliber bullets. The burning material also produces very bright light, enabling its use in flash devices and flares. Because the compositions ignite only at very high temperatures, they can be used in situations that require resistance to large swings in environmental temperature, such as in actuator applications.
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Since metallic fuels have long been used in rocketry and ballistics, there is a great deal of information on the subject that an operative planning the 9/11 attack could draw upon. Additionally, they would be able to take advantage of recent advances in nano-thermite research by some of the same entities that were involved in the official WTC investigations.

By reading NIST's responses to questions about the use of aluminothermic incendiaries, one could get the impression that NIST's investigators had never heard of super-thermites or nano-thermites. Their August 2006 FAQ asserts:

But, as Kevin Ryan points out in his July 2008 article The Top Ten Connections Between NIST and Nano-Thermites, NIST, including its leadership, has been on the forefront of research into advanced aluminothermic mixutures, also described as energetic nanocomposites, metastable intermolecular composites, and superthermites.

Perhaps this explains why NIST's answers to questions about aluminothermic arson seem so transparently disingenuous, and why NIST avoided even mentioning the material in Appendix C of FEMA's Report.