Iron picrate

A fire, followed by an explosion at Huddersfield in 1900 was also caused by detonation of iron picrate (presumably Fe++). The iron picrate had been formed on the surface of steam pipes located in the Picric Acid drier shop. It ignited when a plumber, unaware of the fact, struck one of the pipes with a hammer. The flame spread along the pipe and set the drying Picric Acid on fire... 

If, however, the material is concentrated in a small area or when it is in a confined space, explosion may occur. Burning Picric Acid containing metal picrates may result in explosion. Similarly a potential danger exists when burning Picric Acid is in contact i ith metals, since in the molten state it forms picrates which may initiate explosion. This depends largely on the metal lead, iron, copper should be considered particularly dangerous ... 

Picric acid, in common with several other polynitrophenols, is an explosive material in its own right and is usually stored as a water-wet paste. Several dust explosions of dry material have been reported [1]. It forms salts with many metals, some of which (lead, mercury, copper or zinc) are rather sensitive to heat, friction or impact. The salts with ammonia and amines, and the molecular complexes with aromatic hydrocarbons, etc. are, in general, not so sensitive [2], Contact of picric acid with concrete floors may form the friction-sensitive calcium salt [3], Contact of molten picric acid with metallic zinc or lead forms the metal picrates which can detonate the acid. Picrates of lead, iron, zinc, nickel, copper, etc. should be considered dangerously sensitive. Dry picric acid has little effect on these metals at ambient temperature. Picric acid of sufficient purity is of the same order of stability as TNT, and is not considered unduly hazardous in regard to sensitivity [4], Details of handling and disposal procedures have been collected and summarised [5],... 

The appearance of only one XPS peak for a mixed valence compound is consistent with a delocalized ground state (and excited state). Bifeirocenylene (II, III) picrate, whose structure is shown in Fig. 8, probably fits in this category. The Mossbauer spectrum of the complex indicates only one kind of iron atom, and the Fe 2p3,2 spectrum consists of only one peak with a weak shoulder at higher binding energy 29). It should be recognized, however, that even in the case of a localized system in which two XPS peaks are expected, if the chemical shift between the two peaks is less than the resolution of the spectrometer, only one peak will be observed. 

The conductivity of pyridine is considerably increased by addition of iron carbonyl and corresponds to that of potassium picrate in the same solvent 91 Likewise, DMSO, alcohols, or ammonia95,as well as soft ligands such as triphenylphosphine, may serve as donor molecules 10°1 ... 

Brydon and Roberts- added hemolyzed blood to unhemolyzed plasma, analyzed the specimens for a variety of constituents and then compared the values with those in the unhemolyzed plasma (B28). The following procedures were considered unaffected by hemolysis (up to 1 g/100 ml hemoglobin) urea (diacetyl monoxime) carbon dioxide content (phe-nolphthalein complex) iron binding capacity cholesterol (ferric chloride) creatinine (alkaline picrate) uric acid (phosphotungstate reduction) alkaline phosphatase (4-nitrophenyl phosphate) 5 -nucleotidase (adenosine monophosphate-nickel) and tartrate-labile acid phosphatase (phenyl phosphate). In Table 2 are shown those assays where increases were observed. The hemolysis used in these studies was equivalent to that produced by the breakdown of about 15 X 10 erythrocytes. In the bromocresol green albumin method it has been reported that for every 100 mg of hemoglobin/100 ml serum, the apparent albumin concentration is increased by 100 mg/100 ml (D12). Hemolysis releases some amino acids, such as histidine, into the plasma (Alb). 

One gram of powdered picric acid and as much by volume of litharge (PbO) are mixed carefully on a piece of paper by turning the powders over upon themselves (not by stirring). The mixture is then poured in a small heap in the center of a clean iron sand-bath dish. This is set upon a tripod, a lighted burner is placed beneath it, and the operator retires to a distance. As soon as the picric acid melts and lead picrate forms, the material explodes with an astonishing report. The dish is badly dented or possibly punctured. 

According to both the NFPA Guide and Bretherick (Refs 5 13), sulfuric acid causes explosions and/or fires when in intimate contact with a large number (over 70) of materials including acetic anhydride, acet and nitric acid, acrolein, alcohols, alcohols and hydrogen peroxide, anun hydroxide, aniline, bromine and metals, carbides, chlorates, cyclopentadiene, ethylene glycol, various hydrocarbons, hydrochloric acid, iron, mercuric nitride, powdered metals, perchlorates, picrates, pyridine, Na carbonate, steel, sucrose, vinyl acetate, and w. Illustrative... 

All picrates, especially lead, barium, calcium, iron and nickel picrates, should be considered as highly undesirable in picric acid. They have caused a great number of accidents. Among them only potassium picrate has found some practical uses, viz. in some high explosive and propellant compositions no longer in use at the present time. 

A paste of chloride of lime was first prepared and pumped into a vertical vessel of enamelled iron where it was mixed with calcium picrate prepared previously by mixing picric acid with water and an excess of lime. The mixture was allowed to react at ordinary temperatures for about 2 hours and then a current of steam was introduced at the bottom of the vessel. In these conditions the rise in temperature accelerated the reaction and at 85° C. the chloropicrin began to distil. Distillation was continued until no more chloropicrin came over. 

Tessier introduced the use of cryolite (AlNaaF ) for the yellow coloring of stars, lances, and Bengal lights. In his second edition he includes a chapter on the small pyrotechnic pieces which are knonm as Japanese fireworks, giving formulas for them, and another on the picrates, which he studied extensively. The picrates of sodium, potassium, and ammonium crystallize in the anhydrous condition. Those of barium, strontium, calcium, magnesium, zinc, iron, and copper are hygroscopic and contain considerable water of crystallization which makes them unfit for use in pyrotechnic compositions. Lead picrate, with 1 H3O, detonates... 

C. 1.2 g of picric acid is soluble in 100 g of cold v/ater and 7.2 g in 100 g of hot water soluble in alcohol, ether or benzene. It forms picrates, which are sensitive to shock and friction, in combination with lead, iron, copper or other salts. 

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