Westinghouse Electric Corporation

Young J Kwon

Richard A Stoltz

Harmon A Evans

Edward Jean Lahoda

Herbert A Burgman

Susan M Schulte

A ZrO.sub.2 powder of very fine particle size adapted especially for the making of high density ceramics is produced by chlorinating a zirconium source material, such as zircon sand, to produce crude ZrCl.sub.4 solids; the solids are dissolved to form a ZrOCl.sub.2 solution from which ZrOCl.sub.2 crystals are precipitated; the crystals are dried and milled to a desired particle size; and the crystal particles are subjected to direct oxidation under controlled conditions to produce a very fine ZrO.sub.2 powder especially adapted to the making of high density ceramics.

Production of ZrO.sub.2 powder of very fine particle size

This is a high quality zirconium or hafnium sponge, a fuel element cladding liner having material of the quality of this sponge and a process utilizing this quality sponge to fabricate liner material for lined fuel element cladding. The sponge contains 250-about 350 ppm of oxygen impurity, 50-300 ppm of iron impurity, and a total of 500-1,000 ppm of impurity. This material is much purer than conventional sponge and approaches the quality of crystal bar.

Zirconium and hafnium with low oxygen and iron

A process for distilling zirconium sponge in an iron containing vessel at a temperature sufficiently low to preclude iron contamination of said sponge is disclosed. A distillation temperature near about 934.degree. C. is sufficiently low to minimize iron contamination while being sufficiently high to cause sintering of the sponge to a degree that subsequent comminution does not produce excessive fines.

Process for producing zirconium sponge with a very low iron content

Disclosed is a method for making silane. A silicon tetrahalide having the general formula SiX.sub.4 is reacted with a compound which can be alcohols to C.sub.4, alkanes to C.sub.4, alkenes to C.sub.4 alkenes to C.sub.4 or a mixture thereof, where X is independently selected from the halogens, to produce a product having the general formula SiR.sub.4, where each R is independently selected from alkoxy to C.sub.4, alkyl to C.sub.4, alkylene to C.sub.4 and alkenyl to C.sub.4. The SiR.sub.4 is then reacted with hydrogen to produce the silane.

Manufacture of silane

This is a process for producing high quality zirconium or hafnium sponge. It is especially useful for producing the very high purity zirconium which may be used to line the inner surface zirconium of Zircaloy tubing for nuclear fuel rods. The process uses a combination reduction-distillation vessel which is directly fed with zirconium or hafnium tetrachloride from a molten salt sublimer. A precharge of magnesium chloride is used to prevent reduction of metal outside the inner liner, and thereby facilitate removal of the inner liner after reduction and distillation. The agitator for the molten salt sublimer preferably utilizes a molten metal seal around the agitator shaft.

Process for producing high purity zirconium and hafnium

This is a method for reduction of chlorides of zirconium, hafnium or titanium, and provides a practical method of removing the product metal from the reduction vessel. A seal metal layer is used at the bottom of the vessel. The upper portion of the seal metal layer is liquid and the lower portion is solid. Product metal settles into the liquid portion. Product metal in a matrix of solid seal metal is withdrawn from the bottom of the vessel. Seal metal is predominantly either zinc or tin. Either pure zinc or tin or zinc or tin alloyed with product metal can be recycled to the bottom of the reduction vessel.

Process for reduction of zirconium, hafnium or titanium using a zinc or

This is a method for reducing the chlorides of zirconium, hafnium, or titanium. It utilizes a solidified magnesium (or sodium) chloride matrix in which chunks of the product metal are contained as a seal on the bottom of the reduction vessel. A withdrawal mechanism is used in conjunction with a cooling means (e.g. water jacket) to slowly withdraw the product metal chunks in the salt matrix. This invention makes possible the operation of the reduction process as a continuous process.

Continuous reactive metal reduction using a salt seal

A combination reduction, distillation, reducing metal recovery furnace and process of using the same comprising a pair of vertically displaced vessels in fluid communication wherein the upper vessel contains a perforated inner liner and means to at least periodically charge the top of the vessel with the metal salt to be reduced and a reducing metal, and wherein the lower vessel has a means to periodically withdraw the molten reducing metal salt produced by the redox reaction occurring within the furnace. By initially charging the furnace with sufficient reducing metal salt to establish a liquid level to provide a liquid seal above the bottom of the inner liner and by maintaining this level during the redox reaction, the inner liner can be filled with solid phase reduced metal produced by the reaction (and no reduced metal is produced outside of the liner). Upon completion, the molten reducing metal salt is drained from the furnace, the lower vessel is cooled and the unreacted reducing metal is distilled from the upper vessel and collected in the lower vessel. The unreacted reducing metal can be recycled to the subsequent run by loading a quantity of reducing metal salt into upper vessel and melting it. The reducing metal in the lower vessel is then melted and allowed to float up into the inner liner of the upper vessel where it provides a portion of the reducing metal required for the subsequent run. Such a process and apparatus is useful in producing large quantities of high purity metal such as Zr, Ti, Hf and the like.

Process for combination metal reduction and distillation

This is a control method for large scale batch reduction of zirconium tetrachloride to zirconium metal. Solid zirconium tetrachloride is fed at least periodically into a sublimer and the sublimer heated to vaporize the zirconium tetrachloride. The vaporized zirconium tetrachloride is fed from the sublimer to a reduction vessel and a measurement is made indicative of this feed (e.g., the flow rate or the pressure in the reduction vessel). A condenser is used to conjunction with said sublimer and the temperature of the condenser is controlled to control the feed of the vaporized zirconium tetrachloride. Preferably, a flow restriction is used between the sublimer and the condenser to provide improved control.

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Fruit Heights, UT, United States of America

Young J Kwon