Cheddite

Cheddite (French Cheddite ) is the name for a group of non-homogeneous Chloratsprengstoffen that have been developed and produced from the late 19th century in France, and later in the United Kingdom and Germany. The name derives from the district Chedde in the community Passy (Haute -Savoie ), where Cheddit was first made ​​. The chemist EAEC Street developed the first Cheddit in 1897. As mining explosives obtained Cheddite a great industrial importance, are today but no longer used. Since the mid-20th century, the plastic explosives gelatin Cheddit is used for military purposes.

Composition and types

Cheddite similar in composition to the Sprengel 's Chloratsprengstoffen. By introducing the chlorates in various binders such as oils, resins or gelatin, a relatively high resistance to shock and impact is achieved. The disadvantage is the effect of hygroscopicity of cheap sodium chlorate often used, which can be circumvented by the use of the more expensive potassium chlorate.

There are different types of Chedditen together are each a chlorate and an oily or resinous binder which unhüllt the chlorate and thus reduces the impact sensitivity. Most types in addition contain one or more nitro compounds that are oxidized by the chlorate during the explosion, and partly even have explosive characteristics.

Production

Depending on the type of the nitro compound in an oil or resin is first dissolved at 40-80 ° C, and then the heated chlorate added with stirring. As additional components in small amounts, such as carbon powder, sulfur or ethanol may be added to improve the homogeneity or explosive properties. The resulting mass is mechanically mixed or kneaded and crushed.

Properties and Uses

Due to the high Chloratgehalts are Cheddite friction, impact and fire -sensitive, but to a much lesser extent than mixtures of chlorates with sulfur or charcoal. In a monkey experiment with a five- pound hammer of dynamite detonated similar type 60 with 50 % probability even at 0,253 m drop height. Type 41, however, detonated only ( 50% probability ) at a height of 0,352 m. The explosive was stored over years.

Cheddite were used on a large scale as explosives at the mountain, road and tunnel construction. The Type 60 was used for blasting in very hard rock; Type 41 was mainly used for splitting stones without smashing it completely. Gelatin - Cheddit is manufactured as a military plastic explosive in Switzerland.

Were ignited by Cheddite detonator, about 0.5 to 1.5 grams of mercury fulminate (mercury (II ) fulminate ).