Metal fulminates copper fulminate

The metal fulminates are all powerfully explosive. Of several salts examined, those of cadmium, copper and silver were more powerful detonators than mercury fulminate, while thallium fulminate was much more sensitive to heating and impact. Formally related salts are also explosive [1]. Sodium, potassium, rubidium and caesium fulminates are all easily detonated by feeble friction or heat. They all form double salts with mercury(II) fulminate which also explode readily, that of the rubidium salt at 45 °C [2],... 

Reactions with metals. When mercury fulminate is boiled with water containing metallic suspensions, the majority of metals (e.g. aluminium, zinc, copper), form their fulminates and mercury is precipitated. Reaction can also occur at room temperature, except with nickel. Other metals may be ranged according to increasing reactivity silver, tin, bismuth, cadmium, iron, lead, copper, zinc, brass, aluminium. With aluminium, the reaction takes only a few hours, yielding a large amount of A1203. 

The other fulminates are of no practical value. They are prepared from mercury fulminate either by reacting the metal amalgam with a suspension of mercury fulminate in water (this is applicable to the majority of metals, including the alkali metals, or simply by the action of the metal itself (e.g. zinc or thallium) which displaces mercury from mercury fulminate (also in water). For example, chips of thallium, zinc, or copper are allowed to stand for some time in a suspension of mercury fulminate in water, the corresponding metal fulminate is gradually formed. 

Martin [64] examined the initiating properties of certain fulminates, and found that silver, cadmium and copper fulminates have stronger initiating properties than mercury fulminate. Table 25 and Fig. 45 show the figures obtained by Wohler and Martin [65], expressed as the smallest amounts of the fulminate of different metals necessary to produce detonation of various high explosives. 

Properties Yellow to red crystals or granules. Does not melt on heating but explodes when heated to 300°. It must be loaded in projectiles by pressing or tamping. Ammonium picrate absorbs moisture and in wet condition reacts slowly with metals, particularly copper and lead, to form picrates which are sensitive and dangerous. Its explosive strength is inferior to that of TNT, but it is very valuable because of its extreme resistance to impact, shock, and friction. It is not detonated by fulminate. Commonly used with a booster of picric acid or Tetryl. Rate of detonation 6500 m/sec. (d = 1.45). 

CHAPTER 4 THE PREPARATION OF METAL AZIDES, FULMINATES, AND NITRIDES room temperature for 24 hours. Thereafter, slowly heat the mixture to about 80 Celsius with rapid stirring, and then carefully add 120 grams of 95% ethanol while stirring the reaction mixture. After the addition of the alcohol, remove the heat source, and allow the reaction mixture to cool to room temperature. Afterwards, rapidly filter-off the precipitated copper fulminate, wash with several hundred milliliters of cold water, and then dry in a desiccator filled with anhydrous magnesium sulfate. Should be stored in a desiccator over sodium sulfate in a refrigerator. 

Mercury can also form such compounds. Similarly, ammonia or ammonium ions can react widi gold salts to form "fulminating gold". Metal fulminates of cadmium, copper, mercury and thallium are powerfully explosive, and some are detonators [Luchs, Photog Sci Eng 10 334 1966], Heavy-metal-containing solutions, particularly when organic material is present, should be treated with great respect and precautions towards possible explosion should be taken. 

In contrast to mercury and silver fulminates, most other metallic fulminates are too sensitive, or physically or chemically unstable. Further, their preparation is too expensive and demanding for practical use. Many fulminates are hygroscopic stable when dry but decompose in presence of carbon dioxide when moist (cadmium, copper(I), copper(n), thaUium) [15, 29, 57, 106]. 

Acetylides of heavy metals (silver, copper, gold, mercury) do not react with moisture and are stable in contact with air. These acetylides are very sensitive to mechanical stimuli and have the characteristics of primary explosives. Their explosive power is considered to be the same as that of azides and fulminates [2]. 

At the beginning of the twentieth century the thiocyanates (rhodanates) of certain metals (e.g. mercury, copper) were recommended as components of cap compositions with potassium chlorate. The rhodanates were intended as a substitute for mercury fulminate, but only lead rhodanate acquired any practical significance. 

In early days Alfred Nobel already replaced mercury fulminate (MF, see above), which he had introduced into blasting caps, with the safer to handle primary explosives lead azide (LA) and lead styphnate (LS) (Fig. 1.17). However, the long-term use of LA and LS has caused considerable lead contamination in military training grounds which has stimulated world-wide activities in the search for replacements that are heavy-metal free. In 2006 Huynh und Hiskey published a paper proposing iron and copper complexes of the type [cat]2[Mn(NT)4(H20)2] ([cat]+ = NH4, Na+ M = Fe, Cu NT = 5-nitrotetrazolate) as environmentally friendly, green primary explosives (Fig. 1.17) [3]. 

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