Why does tnt explode not burn

Each of these molecules share the property of being highly strained structurally. Secondary high explosives are those chemicals that do not have to be contained to explode and are relatively stable and safe to handle. They require an electrical spark, fuse, intense heat, or sharp blow to initiate their explosion. Secondary explosives are relatively insensitive to heat, shock, or friction and will normally burn rather than detonate if ignited in small quantities in the open air.

Dynamite, TNT, Semtex plastics are some common examples of this type of explosive. Huge Explosion! Funkyyyyyy YouTube. The process for examining evidence at the site of an explosion is very similar to the process followed at the scene of a fire. Ion Mobility Spectrometer. An Ion-mobility spectrometer IMS is an instrument that detects and separates ions in the gas phase. The technique passes absorbed gases through a tube using a carrier gas to promote flow.

The walls of the tube are electrified so that ions with greater charge are more attracted and move slower through the tube. Large ions also move more slowly through the tube. A detector at the end of the tube recognizes the ions based on their charge and shape. The technique is heavily used by both military and law enforcement purposes; not only detecting explosives but also having use for identification of drugs.

Stephanie R. Secondly, it is not too unstable - allowing it to be handled reasonably safely during manufacture and operation. TNT will not spontaneously explode, and in fact can be treated quite roughly. In order to initiate the explosion, TNT must first be detonated using a pressure wave from another, more easily induced explosion from another explosive called a detonator. One such detonator is lead azide , Pb N 3 2 , which explodes when struck or if an electric discharge is passed through it.

Plastic explosives have been around for a couple of decades. They typically consist of an explosive mixed with an oil or wax plastic resin. One example is C4 plasticized RDX , which has been used by the military and safecrackers! RDX is cyclotrimethylenetrinitramine , another high explosive with a tight, constricted ring structure similar to TNT except containing even more energy-providing N atoms.

This fire then spread to the ammonium nitrate pile which started to burn giving off NOx products, water as a gas and nitrogen. As the ammonium nitrate burnt the gaseous products within the pile could not escape causing the burn rate to increase.

When the speed of the burn became supersonic greater than the speed of sound through the material the ammonium nitrate detonated resulting in a supersonic shock travelling through the material which became a blast wave when it travelled through the atmosphere. The blast wave can travel great distances causing damage to buildings, cars, people etc.

Is there anything that you can tell from the extent of the damage and how away the blast was felt? The pressures would cause damage to the ear drums, lungs, organs, and result in broken bones. The high temperatures would result in burns to the skin and lungs. Ammonium nitrate absorbs water and becomes over a period of time, a hard solid rather than a powder. The velocity of detonation increase with density so the power of the explosion is greater in a solid compared to a powder.

It is found naturally but is made in large quantities by reacting the gas ammonia with nitric acid. In itself it is quite innocuous, being non-poisonous like sodium chloride and stored properly in water-tight containers is relatively stable. Its main applications are as a fertiliser and as a component in explosives used, for instance, in mining. If in an open space where the heat can escape, if heated it decomposes to oxides of nitrogen which are a health hazard and water vapour but will not catch fire.

However, if it comes into contact with an intense source of heat and ignition, such as a detonator or an intense fire for some time, and is present as a large bulk mass e. It decomposes rapidly to gases, because of the confinement heat cannot escape, the gases rapidly expand and the explosion occurs. This releases an enormous amount of energy, and sends out a shock wave as the surrounding air is rapidly compressed which propagates very rapidly over the surrounding area and does enormous damage to buildings and people.

This is what seems to have happened in Beirut yesterday. So this indicates that there may have been a fire close to or even inside the store, which was probably the source of heat and maybe of ignition for flammable packaging which set off the explosion of the tonnes of ammonium nitrate reportedly stored there.

When the explosion happened, a new mushroom shaped cloud rapidly developed and expanded rapidly over a wide area, inland over the port and out over the water. The mushroom type cloud is formed by the rapidly expanding gases which rise upwards as they are heated and so have a lower density than the surrounding air.

The pressure shockwave radiates outwards through the air much more quickly and its effects are felt much further away within seconds. You can see buildings raised to the ground instantly when the pressure wave reaches them.

You can imagine what this will do to any humans in its wake. They stand little chance of surviving. This just illustrates how much energy was released so rapidly from almost tonnes of this chemical. It confirms that a large amount of material must have been involved and that the fire transitioned to a detonation limit to give such a large, rapid explosion. It could be that long-term storage had caused some deterioration of the ammonium nitrate and made it more susceptible to explosion.

For instance, if the storage was not airtight, in the humid conditions of Beirut, the salt could have taken up large quantities of water from the air which would cause the granules and pellets to fuse over time into a large consolidated mass from which heat and gases from the decomposition could not escape as easily as from a dispersed granular, free-flowing pile of fine particles.

This would have just added to the confinement effect which increased the risk of an explosion once a source of heat was applied. The lessons are learned for a while but unless the safety precautions are improved and then permanently monitored, and there is a change in culture that this is a continuous process that requires constant vigilance, not just putting in place a few improved measures at the time. Big accidents include:.

As well as putting much better safety mitigation measures in place and making company management embrace a top-down safety culture, communication between manufacturers and users of these and similar materials across the world is very poor — largely because embedding ensuring the users know about all the lessons from the past and bring in best practice is still not widespread practice. We must do better to learn the lessons of the past, those lessons are written in blood.