Iron Powders

A little iron powder or ferric benzoate can be used as a catalyst. 

Fig. 10. Scanning electron micrograph of amorphous nanostmctured iron powder produced from the ultrasonic irradiation of Fe(CO). ...

A mixed valency pale yeHow crystalline iron pentafluoride heptahydrate, FeF 7H20, is prepared by dissolving iron powder in 40% HF in the presence of air (16). No appHcations have been reported for this material. 

Values given are typical of iron powder samples. Numbers in parentheses represent mesh sizes. 

Specific Surface. The total surface area of 1 g of powder measured ia cm /g is called its specific surface. The specific surface area is an excellent iadicator for the conditions under which a reaction is initiated and also for the rate of the reaction. It correlates in general with the average particle size. The great difference in surface area between 6-p.m reduced iron powder and 7-p.m carbonyl iron powder (Table 3) cannot be explained in terms of particle size, but mainly by the difference between the very inregular-shaped reduced and the spherical carbonyl iron powders. 

The raw precious metal concentrate is totally dissolved in hydrochloric acid—chlorine solution to form the soluble chloride ions of each of the metals. Silver remains as insoluble silver chloride and can be filtered off. Gold, in the form of [AuClJ, is extracted with, eg, tributyl phosphite or methyl isobutyl ketone. Base metals are also extracted in this step, and are removed from the organic phase by scmbbing with dilute hydrochloric acid (HCl). Iron powder is then used to reduce the gold species and recover them from the organic phase. 

Other Uses. The production of finished shapes from iron powder by compacting and sintering utilizes about 100,000 t of iron powder aimuaHy copper powder (2—10 wt %) is normally added as a sintering aid. Addition of 2% tin powder or equal amounts of tin and copper powder considerably lowers the sintering temperature and time of sintering at a cost saving. The tin addition also improves dimensional control. Iron powder plus 10 wt % powdered lead—tin metal is pressed and siatered to make pistons for use ia automotive hydrauHc brake cylinders. 

For solvent extraction of a tetravalent vanadium oxyvanadium cation, the leach solution is acidified to ca pH 1.6—2.0 by addition of sulfuric acid, and the redox potential is adjusted to —250 mV by heating and reaction with iron powder. Vanadium is extracted from the blue solution in ca six countercurrent mixer—settler stages by a kerosene solution of 5—6 wt % di-2-ethyIhexyl phosphoric acid (EHPA) and 3 wt % tributyl phosphate (TBP). The organic solvent is stripped by a 15 wt % sulfuric acid solution. The rich strip Hquor containing ca 50—65 g V20 /L is oxidized batchwise initially at pH 0.3 by addition of sodium chlorate then it is heated to 70°C and agitated during the addition of NH to raise the pH to 0.6. Vanadium pentoxide of 98—99% grade precipitates, is removed by filtration, and then is fused and flaked. 

A Japanese patent has claimed improvements in the direct condensation of menadione with phytyl chloride in the presence of a reducing metal such as 2inc or iron powder (30). Tin chloride has been reported to be a useful catalyst for this condensation (31,32). 

Carbonyl Iron Powders, General Aniline and Film Corporation, New York, 1962. 

Liquid benzene is chlorinated in the presence of metalhc iron turnings or Raschig rings at 40 to 60°C (104 to 140°F). Carbon tetrachloride is made from CS9 by bubbling chlorine into it in the presence of iron powder at 30°C (86°F). 

Magnetite and cai bonyl iron powders used in biomedical pui poses ai e not consistent with above-mentioned requirements. 

In a 250-ml. three-necked flask, fitted with a mechanical stirrer, a reflux condenser, and an inlet for admission of nitrogen, is placed 100 ml. of tetrahydrofuran (Note 1). With stirring, 27.1 g. (0.166 mole) of anhydrous ferric chloride is added in portions, followed by 4.7 g. (0.084 gram atom) of iron powder (Note 2). The mixture is heated with stirring under nitrogen at the reflux temperature for 4.5 hours, giving a gray powder with a brown supernatant liquid. 

The quality of the iron used in preparing the ferrous chloride has a marked effect on the yield of ferrocene. The checkers employed Rascher and Betzold (730 N. Franklin, Chicago, 111.) 300-mesh iron powder, reduced by hydrogen. When 40-mesh iron filings were used, the yield of ferrocene was much lower (ca. 33%). 

All precautions with regard to the purification of tetrahydrofuran, the quality of the iron powder, the rapid stirring, the maintenance of a nitrogen atmosphere, and the handling of cyclopentadiene, described in the preceding preparation, are followed. 

Stirring was attempted during the ARC tests, but the iron powder interfered with the mechanically coupled stirrer [4],... 

The antiparasitic drug clorsulon (206), contains a rather unusual trichloroethylene group. This function is established early in the syntliesis by treatment of the perhalogenated compound 203 obtained from reduction of 202 with iron powder. Chlorosulfonation of 204 by means of chloro-sulfonic acid, followed by conver.sion of. sulfonyl chloride 205 to the amide, gives clorsulon (206) 153],... 

A new selective reduction of nitroalkenes into enamides has been carried out by a combina-m of iron powder, a carboxylic acid, and the corresponding anhydnde fEq 6 64)... 

For the preparation of nitrocymene a method developed in the Colour Laboratory and described in the Jour, of Ind. and Eng. Chem. in 1918, p. 453, was used. The nitro group enters in the ortho position with respect to the methyl group. The reduction of this compound to aminocymene or cymidine was accomplished by means of iron powder and hydrochloric acid in exactly the same way as nitrobenzene is reduced to aniline. 

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