Zirconium Metal Producers

Blumenthal, W.B. (1958) The Chemical Behavior of Zirconium. Van Nostrand, Princeton, NJ. 

Hedrick, J.B. (2003) Zirconium. In Mineral Yearbook 2003, US Geological Survey, Washington, D.C. 

Lustman, B. Kevse, F., Jr. (eds.) (1955) Metallurgy of Zirconium. McGraw-Hill, New York. 

Larsen, E.M. (1970) Zirconium and hafnium chemistry. Adv. Inorg. Chem. Radiochem., 13,1-333. 

Roskill (1995) The Economics of Zirconium, 8th ed. Roskill Information Services, London. 

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Other Reductions. Ductile, pure zirconium has been made by a two-stage sodium reduction of zirconium tetrachloride (68) in which the tetrachloride and sodium are continuously fed into a stirred reactor to form zirconium dichloride [13762-26-0], heating with additional sodium yields zirconium metal. Leaching with water removes the sodium chloride from the zirconium. Bomb reduction of pure zirconium tetrafluoride with calcium also produces pure metal (69). 

Electrolysis. Electrowinning of zirconium has long been considered as an alternative to the KroU process, and at one time zirconium was produced electrolyticaHy in a prototype production cell (70). Electrolysis of an aH-chloride molten-salt system is inefficient because of the stabiUty of lower chlorides in these melts. The presence of fluoride salts in the melt increases the stabiUty of in solution, decreasing the concentration of lower valence zirconium ions, and results in much higher current efficiencies. The chloride—electrolyte systems and electrolysis approaches are reviewed in References 71 and 72. The recovery of zirconium metal by electrolysis of aqueous solutions in not thermodynamically feasible, although efforts in this direction persist. 

Hydrides. Zirconium hydride [7704-99-6] in powder form was produced by the reduction of zirconium oxide with calcium hydride in a bomb reactor. However, the workup was hazardous and many fires and explosions occurred when the calcium oxide was dissolved with hydrochloric acid to recover the hydride powder. With the ready availabiHty of zirconium metal via the KroU process, zirconium hydride can be obtained by exothermic absorption of hydrogen by pure zirconium, usually highly porous sponge. The heat of formation is 167.4 J / mol (40 kcal/mol) hydrogen absorbed. 

Qua.driva.Ient, Zirconium tetrafluoride is prepared by fluorination of zirconium metal, but this is hampered by the low volatility of the tetrafluoride which coats the surface of the metal. An effective method is the halogen exchange between flowing hydrogen fluoride gas and zirconium tetrachloride at 300°C. Large volumes are produced by the addition of concentrated hydrofluoric acid to a concentrated nitric acid solution of zirconium zirconium tetrafluoride monohydrate [14956-11-3] precipitates (69). The recovered crystals ate dried and treated with hydrogen fluoride gas at 450°C in a fluid-bed reactor. The thermal dissociation of fluorozirconates also yields zirconium tetrafluoride. 

The tlrree impurities, iron, silicon and aluminium are present in the metal produced by the Kroll reduction of zirconium tetrachloride by magnesium to the extent of about 1100 ppm. After dre iodide refining process tire levels of these impurities are 350, 130 aird 700ppm respectively. The relative stabilities of the iodides of these metals compared to that of zirconium can be calculated from the exchange reactions... 

These methods may prove useful in the qualitative analysis of organic compounds, once the selectivities of the precipitants are understood. The metallic oxides suffer from the disadvantage of producing a precipitate which is difficult to filter, while calcite and zirconium phosphates produce relatively well-mannered precipitates. Even when the efficiencies of collection of various model compounds in seawater is known, the immense variety of organic compounds in seawater will keep this technique largely qualitative. 

Zirconium metal is produced from its tetrachloride by reduction with magnesium by the Kroll process. The oxide obtained above is converted to zirconium tetrachloride by heating with carbon and chlorine. In practice, the oxide is mixed with lampblack, powdered sugar, and a little water, and pelletized. The dried pellet is then heated with chlorine in a chlorinator to produce ziro-conium tetrachloride ... 

Zirconium tetrachloride is reduced by heating with sodium, potassium or magnesium at high temperatures. Such reduction of tetrachloride has been the commerical method of producing zirconium metal ... 

The migratory insertion of alkyl and aryl isocyanides into metal alkyl bonds produces an iminoacyl function. The early transition metal iminoacyl, like its oxygen counterpart, has been shown to bond in a dihapto fashion.62 It has recently been shown that it is possible to couple either an acyl and art iminoacyl or two iminoacyls on the metals titanium or zirconium to produce enamidolate and enediamide ligands, respectively (equation 34).62,63... 

Ziegler, an organic chemist who had little experience with polymers, recognized that this unanticipated result might lead to a method to make linear polyethylene. He knew that there would be a demand for such a material from any number of industrial companies, and he wanted to be the one to hold the first patents. He told his student, Heinz Breil, to test the reaction with ethylene systematically with as many other metals as he could find. In a short time, after trying a number of different metals, Breil ran a reaction laced with zirconium and produced a large quantity of linear polyethylene. 

SYNS ZIRCAT ZIRCONIUM (ACGIH,OSHA) ZIRCONIUM, dry, coiled wire, finished metal sheets, strip (UN 2858) (DOT) ZIRCONIUM, dry, finished sheets, strip or coUed wire (UN 2009) (DOT) ZIRCONIUM METAL, dr , chemically produced, finer than 20 mesh pardcle size (UN 2008)... 

ZIRCONIUM METAL, dry, chemically produced, finer than... 

Many zirconium alloys are available. They are used to make flash bulbs, rayon spinnerets (the nozzles from which liquid rayon is released), lamp filaments, precision tools, and surgical instruments. These uses make up only a small amount of the metal produced, however, compared to its application in nuclear power plants. 

Chlorination of zircon has been the process mainly used in the United States because it produces ZrCU, which is used in the Kroll process for making zirconium metal (Sec. 8.3), and because ZrCU was the feed material for the first process developed for separating hafnium from zirconium, using thiocyanate extraction (Sec. 7.3). 

Two recent patents [M2, M3] by J. A. Megy describe a process in which zirconium metal is reduced from a salt and separated from hafnium in the same step, thus shortening the long series of steps in present processes for producing reactor-grade rirconium from natural zircon. 

In the United States, practically all zirconium metal is now being made by the Kroll process. This process was an adaptation to zirconium of a similar process for titanium developed by W. J. Kroll. The work of Kroll and metallurgists of the Albany, Oregon, station of the Bureau of Mines culminated in a plant to produce 135,000 kg zirconium/year at the station. A similar plant was operated by the Carborundum Metals Corporation, at Akron, New York. These have been superseded by the plant of the Teledyne Wah Chang Albany Company, at Albany, Oregon, with a capacity in 1978 of 3.4 million kg/year. 

The largest cell developed [R2] produced zirconium at a rate of from 4 to 6 Ib/h, and 30 to 40 lb of zirconium metal per run. A cell could be used for a minimum of six runs before the operation was terminated by buildup of NaF and KF formed in the overall reaction... 

Draw up a detailed material flow sheet showing the quantities of electric energy and chemicals required to produce 1 lb of hafnium-free zirconium metal. Where information is lacking, make what you consider to be plausible assumptions regarding material losses and the extent to which recycling of materials would be necessary and practical. What is the cost of chemicals and electrical energy consumed in producing 1 lb of zirconium ... 

Zircon is a sihcate of formula ZrSi04 and occurs as the gemstones hyacinth and zirconite. Synthetic gemstones are prepared from zircon and from the oxide Zr02. Zirconium metal is difficult to produce. Its production requires treatment of the tetrachloride ZrC with magnesium metal. Zirconium metal is silvery-gray, ductile, and malleable. 

From the study of cell potentials, the equilibrium constants for various reductions in the equimolar sodium-potassium chloride melt were calculated 550) (Table XXVII). The high values of the equilibrium constants indicate that zirconium metal should reduce any tetravalent or trivalent zirconium present to the divalent species. The reduction in both cases should he quantitative. It can also be predicted that zirconium trichloride in solution does not disproportionate to any significant extent, and that the reaction between zirconium dichloride and tetrachloride to produce zirconium trichloride proceeds almost to completion. 

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