Incandescent contact

Contact with selenium or sulfur vapour causes the heated carbide to incandesce. Contact of the carbide with molten potassium chlorate, potassium nitrate or even potassium hydroxide causes incandescence. 

Chemical and thermal burns. The causes of chemical bums include the effect of concentrated acids, alkali, liquid ammonia, chlorosilanes and other aggressive substances. Thermal bums are caused with boiling solutions, hot water, vapour, inflamed gases, incandescent contact mass. Preventive and protective measures mostly include strict observance of all the established technological regulations and equipment maintenance order. 

Boron enflames in contact with IF3 so do P, As and Sb. Molybdenum and W enflame when heated and the alkali metals react violently. KH and CaC2 become incandescent in hot IF3. However, reaction is more sedate with many other metals and non-metals, and compounds such as CaCOs and Ca3(P04)2 appear not to react with the liquid. 

Mg ribbon and fine Mg shavings can be ignited at air temps of about 950°F (Ref 26). Oxides of Be, Cd, Hg, Mo and Zn can react explosively with Mg when heated (Ref 8). Mg reacts with incandescence when heated with the cyanides of Cd, Co, Cu,Pb, Ni or Zn or with Ca carbide (Ref 9). It is spontaneously flam-mable when exposed to moist chlorine (Ref 10), and on contact with chloroform, methyl chloride (or mixts of both), an expl occurs (Ref 4). Mg also reacts violently with chlorinated hydrocarbons, nitrogen tetroxide and A1 chloride (Ref 14). The reduction of heated cupric oxide by admixed Mg is accompanied by incandescence and an expin (Ref 7).Mg exposed to moist fluorine is spontaneously flammable (Ref 11). When a mixt of Mg and Ca carbonate is heated in a current of hydrogen, a violent ex pin occurs (Ref 12). When Mo trioxide is heated with molten Mg, a violent detonation occurs (Ref 1). Liq oxygen (LOX) gives a detonable mixt when... 

Aluminum carbide. Incandescence on heating Ammonia, Surfuric acid. Ammonia is oxidized with incandescence in contact with the per-... 

P pentachloride causes ignition on contact with Al powder (Ref 2), while contact with a mixt of chlorine and chlorine dioxide usually results in expln, possibly due to formation of the more sensitive chlorine monoxide (Ref 5). Interaction with diphosphorus trioxide is rather violent at ambient temp (Ref 3) treatment with fluorine causes the entire mass to become incandescent (Ref 1). Ignition occurs when hydroxylamine is mixed with P pentachloride (Ref 6), while mixts with Mg oxide react with brilliant incandescence (Ref 7). The residue from interaction of P pentachloride and anilide in benz and removal of solvent and phosphoryl chloride in vacuo expld violently on admission of air (Ref 12). A soln of P pentachloride in nitrobenzene is stable at 110°, but begins to de-... 

Several laboratory explns have occurred when using the reaction between P trichloride and acetic acid to form acetyl chloride. Poor heat control probably caused formation of phosphine (Ref 2). Two later explns may have been due to ingress of air and combustion of traces of phosphine (Ref 8). Al powder burns in P trichloride vapor (Ref 4) K ignites and molten Na explds on contact (Ref 3). Each drop of chromyl chloride added to well-cooled P trichloride produces a hissing noise, incandescence, and sometimes an expln (Ref 5). It reacts with fluorine with incandescence (Ref 1), and with ignition... 

In the presence of boron trichloride or trifluoride (Lewis acids), ammonia is likely to detonate. In contact with boron, it causes incandescence. 

In contact with phosphorus, beryllium incandesces (formation of a phosphide ). 

Chlorine has caused numerous accidents with metals. Beryllium becomes incandescent if it is heated in the presence of chlorine. Sodium, aluminium, aluminium/titanium alloy, magnesium (especially if water traces are present) combust in contact with chlorine, if they are in the form of powder. There was an explosion reported with molten aluminium and liquid chlorine. The same is true for boron (when it is heated to 400°C), active carbon and silicon. With white phosphorus there is a detonation even at -34°C (liquid chlorine). 

With ammonia, when it is hot, calcium becomes incandescent. When it is cold, in liquid ammonia, a harmless solution is created. However, the evaporation of ammonia leaves calcium powder, which is extremely reactive. It combusts violently and instantaneously in contact with air. 

The contact of sodium or potassium causes incandescence of the mixture. 

It incandesces with chlorine at 300°C and combusts in contact with bromine vapour at 400°C. 

The same goes for peroxides and superoxides. Thus, tin powdered which was in contact with sodium peroxide in a carbon dioxide atmosphere in the presence of water traces glowed before combusting. With potassium superoxide there is an immediate incandescence of the mixture. 

A pyrotechnic mixture of sulphide/potassium chlorate/aluminium has led to regular detonations. This sulphide incandesces as soon as it is in contact with chloric acid. Mixtures of antimony trisuiphide with alkaline nitrates, which are probably used for pyrotechnic purposes, also lead to detonations. Bengal lights has been made with this mixture, which was used in small quantities in mixtures and no accidents were experienced. Finally, dichlorine oxide detonates in contact with this sulphide. 

There are other sulphur derivatives which react violently. Lead peroxide combusts in contact with sulphuric acid. It forms an explosive mixture with sulphuryl chloride and incandesces in sulphur dioxide. 

Bismuth trioxide incandesces with sodium or potassium. Bismuth halogens (chlorinated, brominated, iodated) detonate in contact with potassium. 

When gaseous fluorine comes into contact with phenylamine, N,N-dimethylaniline or pyridine, there is incandescence. 

Fig.4.3. Experimental arrangement for investigation of pyrolysis of molecules by the method of semiconductor sensors 1 - reaction vessel, 2 - quartz slab with a ZnO film (sensor), 3 - filter, 4 - contacts, 5 - incandescent filament, 6 - thermocouple, 7 - cell with a substance, 8 - lamp - manometer, 9 - pin, 10 - flask, 11 - sealing bulkhead, 12 - trap, 13 - thermostat.

In contact with finely divided (reduced) silver, incandescence occurs. 

Powdered aluminium ignites in the vapour of arsenic trichloride or sulfur dichloride, and incandesces in phosphorus trichloride vapour [1], Above 80°C, aluminium reacts incandescently with diselenium dichloride [2], The powder ignites in contact with phosphorus pentachloride [3],... 

Chlorine Trifluoride Tech. Bull. , Morristown, Baker Adamson, 1970 Incandescence is caused by contact with bromine, iodine, arsenic, antimony (even at -10°C) powdered molybdenum, niobium, tantalum, titanium, vanadium boron, carbon, phosphorus or sulfur [1], Carbon tetraiodide, chloromethane, benzene or ether ignite or explode on contact, as do organic materials generally. Silicon also ignites [2],... 

The carbide bums incandescently at red heat in contact with dinitrogen mono- or tetra-oxides. 

Masdupay, E. et al., Compt. rend., 1951, 232, 1837-1839 It is much more reactive than the diacetylide, and ignites in contact with water or ethanol in air. It may incandesce on heating to 150°C under vacuum or hydrogen, the product from the latter treatment being very pyrophoric owing to the presence of pyrophoric carbon. 

Finely divided (pyrophoric) cobalt decomposes acetylene on contact, becoming incandescent. 

Contact with water vapour slowly causes incandescence, while a limited amount of water or dilute acid causes rapid incandescence with ignition of evolved ammonia and hydrogen. 

Mellor, 1941, Vol. 2, 292 1956, Vol. 2, Suppl. 1, 380 1943, Vol. 11, 26 Liquid chlorine at —34°C explodes with white phosphorus, and a solution in heptane at 0°C ignites red phosphorus. Boron, active carbon, silicon and phosphorus all ignite in contact with gaseous chlorine at ambient temperature. Arsenic incandesces on contact with liquid chlorine at —34°C, and the powder ignites when sprinkled into the gas at ambient temperature. Tellurium must be warmed slightly before incandescence occurs. 

Borondiiodophosphide, phosphine, phosphorus trioxide and trimercury tetraphosphide all ignite in contact with chlorine at ambient temperature. Trimagnesium diphosphide and trimanganese diphosphide ignite in warm chlorine [1], while ethylphosphine explodes with chlorine [2], Unheated boron phosphide incandesces in chlorine. 

Contact with the heated oxide causes incandescence. 

Above 150-200°C, incandescence occurs with fluorine, chlorine or iodine. In presence of moisture, contact at ambient temperature with carbon monoxide or carbon dioxide causes ignition, while dry sulfur dioxide causes incandescence on heating. 

Arsenic trioxide and calcium oxide incandesce in contact with liquid hydrogen fluoride. 

Aniline, dimethylamine and pyridine incandesce on contact with fluorine. 

Arsenic trioxide reacts violently and nitrogen oxide ignites in excess fluorine. Bubbles of sulfur dioxide explode separately on contacting fluorine, while addition of the latter to sulfur dioxide causes an explosion at a certain concentration [1], Reaction of fluorine with dinitrogen tetraoxide usually causes ignition [2], Interaction with carbon monoxide may be explosive. Anhydrous silica incandesces in the gas, and interaction with liquid fluorine at — 80°C is explosive [3,4], Boron trioxide also incandesces in the gas [3],... 

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