In 1856, however, the financial situation changed completely as, with the end of the Crimean War, the military cancelled their orders for equipment. So, Nobel and his father began to look for new products (Fant, 12-14).
It was probably through his chemistry teachers Professors Yuli Trapp (1809-1882) and Nikolay N. Zinin (1812-1880) that Alfred Nobel first heard about nitroglycerine (pyroglycerine). This explosive substance had been discovered some years earlier by a young Italian chemist, Ascani Sobrero, while he worked in Pelouzes laboratory in Paris (Fant, 15-21).
Encouraged by Zinin, Alfred Nobel began to experiment with nitroglycerine as an explosive in construction work, and his father took an active part in these studies. However, Immanuel Nobel and his company were once again facing bankruptcy, so Immanuel, his wife and the youngest son, Emil, returned to Sweden in 1859 (Sohlman, 93).
Alfred stayed on in St Petersburg, in an apartment that he shared with his brothers. He turned the kitchen into a laboratory and undertook very dangerous experiments to find out how to manufacture nitroglycerine in large quantities. In the winter of 1862-1863, Alfred Nobel and his brothers carried out test explosions on the ice of the river Neva, and developed naval mines. But his brothers, Ludvig and Robert, soon focused on reconstructing the family business and became very wealthy after successfully developing the oil industry in the southern part of the Russian Empire.
In 1863, Alfred Nobel obtained his first Swedish patent on the use of the mercury percussion detonator of nitroglycerine (blasting oil) as an explosive in construction work. One of the first main applications was in blasting a railroad tunnel that joined the main north/south railway line in Stockholm. However, several explosions which included one in 1864 that killed Nobels brother Emil and several other people convinced the authorities that the use of nitroglycerine was exceedingly dangerous. In Stockholm, experimentation with nitroglycerine was forbidden within the city limits, and Alfred Nobel had to move his studies to a barge, which was anchored on Lake M¤laren, close to Stockholm.
However, Alfred was not discouraged and in 1864 he was able to start mass production of nitroglycerine. During a brief visit to Paris, he also managed to obtain a large loan from a French bank. He founded nitroglycerine companies in Sweden (1864), Norway (1865), Germany (1865) and the United States (1866). But, after several accidents in Europe and the United States, the authorities introduced regulations that restricted the possibilities of manufacturing and transporting explosives (Sohlman, 156-63).
Invention of Dynamite
To make the handling of nitroglycerine safer, Alfred Nobel experimented with different additives. While working on a raft which was anchored on the river Elbe outside Hamburg, he found that mixing nitroglycerine with silica (Kieselguhr, diatomous sand) would turn the liquid into a paste, which could be shaped into rods of a size and form that was suitable for insertion into drilling holes. In 1867, he patented this material under the name dynamite. To be able to detonate the dynamite rods, he had to modify his original blasting cap. (Alfred Nobel His Life and Work)
Dynamite is by far the most widely used blasting explosive, Trinitrotoluene (TNT) is the main high explosive ingredient of shells and bombs. Black powder (a mixture of charcoal, sulfur and potassium nitrate) was the only industrial explosive till Alfred Nobel introduced liquid nitro glycerine for rock blasting in 1863. Black powder is still used in pyrotechnic devices. The modem era of Industrial explosives began with Nobels invention of the detonator in 1865, and of the first dynamite and blasting gelatin during 1867-75. This invention is of great importance since dynamite has much greater safety and shattering power than black powder and at much lower cost (Waal, 223-228).
Dynamite was made by mixing nitroglycerin with diatomite. The diatomite absorbed the liquid nitro, stabilizing it. The resultant paste was formed into sticks that were safe to transport and handle. Blasting caps were used to set off the dynamite.
Uses of industrial explosives in-dude blasting ore, coal and rock in mining and construction, seismic prospecting for oil and gas, stimulating and perforating gas and oil wells, bonding sheets of dissimilar metals, synthesizing of Industrial diamonds, metal forming etc. (Waal, 223-228).
To avoid toxic fumes underground or fumes that can give secondary explosions when mixed with air, industrial explosives are usually oxygen-balanced to minimize CO, NOx, and H2 in the reaction products. In typical modem dynamite, nitroglycerine containing a nitrocellulose thickener is adsorbed on a mixture of ammonium nitrate and cellulosic fuel to form a cohesive, plastic mass which is packaged in paper cartridges (Waal, 223-228). The composition, including the cartridge, is approximately oxygen balanced, that is, the oxygen balance is about zero.
In an oxygen-balanced composition, the amount of oxygen present is just sufficient to oxidize all the carbon CO2 and all the hydrogen to H2O and any metals present to their oxides. If the oxygen is insufficient to do this, the oxygen balance is said to be negative, and if it is more than sufficient, it is said to be positive. Explosive containing only C, H, N and O exhibit their maximum energy at a slightly negative oxygen balance and a minimum production of toxic NOx and CO at about zero oxygen balance.
Most industrial blasting is done with ANFO, a free flowing mixture of ammonium nitrate (AN) in the form of small spheres (prills) and six-percent No.2 diesel fuel oil, sometimes with aluminium powder to increase the energy. AN prills are made by the solidification of droplets of molten AN during free fall in a short tower. ANFO is a very low-cost, oxygen balanced explosive with adequate sensitivity and energy for most industrial blasting in dry holes of relatively large diameter. Prilled AN alone is a relatively weak explosive having a positive oxygen balance. It is too difficult to initiate and has too large critical diameter to be a useful explosive in itself.
Most military explosives are simple compositions formulated for high energy density, loading in a munitions plant, and long storage life. Most of them are based on explosive chemical compounds that incorporate both oxidizer and fuel components in the same molecule.(Explosive)
The most important use of dynamite are in construction, mining and demolition industries. However, modified versions of explosives & techniques have substituted for the conventional dynamite in many applications. The use of dynamite, in underwater blasting has continued the in the same way as it was originated, several years ago. Dynamite has been excessively used in armed conflicts, mainly to demolish bridges and altenatives of travelling, to put a stop to the advancement of the supplies or the enemy troops. Enthusiasts interested in decomposing the compound have deliberately seperated nitroglycerin from dynamite.
Dynamite is very commonly used in ski resorts as well. The safety patrolers make use of the sticks of the explosive device, delibrately, to create avalanches so the runs can be safe once the skiiers arrive (Perrings, 129-135).