Abstract: The invention relates to a method for producing lithium transition metalates of the general formula (I): Lix(M1yM21−y)nOnz, where M1 represents lithium, cobalt or manganese; M2 represents cobalt, iron, manganese or aluminium and is not equal to M1; n is equal to 2 if M1=M, and 1 in all other cases; x is a number between 0.9 and 1.2; y is a number between 0.5 and 1.0; and z is a number between 1.9 and 2.1. According to the method, an intimate solid mixture is produced of oxygen-containing compounds of the transition metals and oxygen-containing lithium compounds and this mixture calcinated in a reactor, whereby calcination takes place at least partly at an absolute pressure of less than 0.5 bar.
Type:
Grant
Filed:
August 19, 1999
Date of Patent:
September 10, 2002
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Ulrich Krynitz, Wolfgang Kummer, Mathias Benz, Juliane Meese-Marktscheffel, Evelyn Pross, Viktor Stoller
Abstract: Refractory metal products, such as tantalum on non-refractory conductive metal backings, e.g. copper, can be rejuvenated after metal consumption in selected zones by powder filling the zones and high energy heating at high scan speed to sinter the added powder, without complete melting of the powder fill, thus establishing a microstructure consistent with the balance of the reclaimed product and avoiding the separation of the copper backing and tantalum sputter plate. The rejuvenation method can be applied to non-mounted refractory metal products that are subject to non-uniform erosion, etching, chipping or other metal loss. The form of such refractory metal products can be as plate, rod, cylinder, block or other forms apart from sputter targets. The process can be applied to, for example, x-ray disks or targets (molybdenum plate on carbon backing).
Type:
Application
Filed:
February 14, 2002
Publication date:
August 22, 2002
Applicant:
H.C. Starck, Inc.
Inventors:
Paul Aimone, Prabhat Kumar, Peter R. Jepson, Henning Uhlenhut, Howard V. Goldberg
Abstract: A method (10) of forming sputtering target (11) from ingots of tantalum or niobium of requisite purity by the process of cutting the ingot to short lengths (12) and pressure working (14, 22, 30, 34) the ingot along alternating essentially orthogonal work axes. Intermediate anneals (18, 26, 38) are applied as necessary to establish a uniform texture thickness-wise and area-wide throughout the target, including the center. The uniform texture is a substantially constant mix of grains with orientation {100} and {111}, thereby improving sputtering performance by providing a more predictable sputter rate to control film thickness.
Type:
Application
Filed:
February 20, 2002
Publication date:
August 22, 2002
Applicant:
H.C. Starck, Inc.
Inventors:
Peter R. Jepson, Henning Uhlenhut, Prabhat Kumar
Abstract: A method of making sheet bar and other precursors of formed products to be made by extensive working. The method includes providing a powder metal, preferably under 100 PPM oxygen content of non-spherical particles, compacting the powder into a coherent precursor form of at least 100 pounds, whereby a precursor is provided enabling extended fabrication to a finished product form. The finished product is resistant to breakup in fabrication due to oxide inclusion effect and produces a low oxygen end product. The method can process multiple species of metals that include at least one higher melting metal and one lower melting metal to produce an alloy or micro-composite of the metals as worked, where one metal is preferably a refractory metal (Ta, Nb, W, Wo, Zr, Hf, V and Re). The process is controlled to cause powder of the higher melting metal to be extended into a fibrous form.
Type:
Application
Filed:
July 16, 2001
Publication date:
April 11, 2002
Applicant:
H.C. Starck, Inc.
Inventors:
Prabhat Kumar, Paul Aimone, Robert W. Balliett, Peter R. Jepson, Anthony V. Parise, Thomas M. Ramlow, Henning Uhlenhut
Abstract: Refractory metal articles having hither than normal impurity levels of concentrations of additive species near the surface that promote chemically enhanced sintering without any adverse effect on function properties, including, among others, tantalum or niobium lead wires that form assemblies useful as electrolytic capacitor anodes and the like, as made by surface oxidation of the wire, embedding a wire end in a loose mass of the powder and sintering to producing assemblies of enhanced structural integrity and affording stable electrical characteristics of electrical devices including such assemblies.
Type:
Grant
Filed:
May 9, 2000
Date of Patent:
March 19, 2002
Assignee:
H. C. Starck, Inc.
Inventors:
Prabhat Kumar, Howard V. Goldberg, Thomas Ryan
Abstract: Ultrafine cobalt metal powder consisting of fine crystallites, wherein the crystallites, wherein the crystallitex exhibit a rice-grain shaped to spherical habit and more than 90% of the crystallites have a diameter in the range of from 0.5 to 2 &mgr;m, a process for the production of the cobalt metal powder via an intermediate stage of cobalt carbonate production, and processes and products re certain uses of the cobalt metal powder and the cobalt carbonate and an intermediate oxide so produced.
Abstract: The present invention relates to cobalt(II) oxide containing metallic cobalt, to a process for the production thereof and to the use thereof.
Type:
Grant
Filed:
December 17, 1999
Date of Patent:
August 21, 2001
Assignee:
H. C. Starck GmbH & Co. KG
Inventors:
Astrid Görge, Juliane Meese-Marktscheffel, Dirk Naumann, Armin Olbrich, Frank Schrumpf
Abstract: Production of low oxygen forms of tantalum and other refractory metals providing hydrided powder of the metal, forming a tube (10), pouring the metal into the tube, dehydriding the powder in the tube and sealing the tube and extruding to form a rod encased in the tube and further fabricating the rod.
Abstract: The present invention discloses a tantalum powder for capacitors and a method for making said tantalum powder wherein agglomerated tantalum powder is produced by means of thermal agglomeration of starting tantalum powders in the presence of hydrogen.
Abstract: Tantalum scrap of high oxygen content is recovered and processed to metallurgical grade tantalum by fine participation. Blending with carbon or other appropriate solid reducing agent, melting in a plasma furnace (20) at about tantalum melt temperature while suppressing partial pressure of tantalum oxide gas to minimize tantalum loss of the process.
Type:
Grant
Filed:
February 17, 1999
Date of Patent:
March 6, 2001
Assignee:
H.C. Starck, Inc.
Inventors:
Robert A Dorvel, Leonid N. Shekhter, Ross W. Simon
Abstract: The invention relates a tantalum powder free of alkali and fluorine, which for a relatively small primary particle size has comparatively large secondary particles and is suitable for producing capacitors with a specific charge of between 100,000 and 180,000 &mgr;FV/g at specific residual currents of less than 2nA/&mgr;FV.
Abstract: Metal powder from the group Ta, Nb, Ti, Mo, W, V, Zr, Hf preferrably Ta or Nb, is made in a fine powder form by reduction of metal oxide by contact with a gaseous reducing agent, preferrably an alkaline earth metal, to near complete reduction, leaching, further deoxidation and agglomeration, the powder so produced being sinterable to capacitor anode form and processable to other usages.
Type:
Grant
Filed:
May 6, 1998
Date of Patent:
January 9, 2001
Assignee:
H. C. Starck, Inc.
Inventors:
Leonid N. Shekhter, Terrance B. Tripp, Leonid L. Lanin
Abstract: The process comprises the reduction of niobium and/or tantalum oxides by means of alkaline earth metals and/or rare earth metals, wherein the first reduction stage is carried out as far as an average composition corresponding to (Nb, Ta)O.sub.x where x=0.5 to 1.5 and before the second stage the reduction product from the first stage is freed from alkaline earth oxides and/or rare earth metal oxides which are formed (and optionally from excess alkaline earth metal and/or rare earth metal) by washing with mineral acids.
Abstract: The invention concerns metal powder granulates comprising one or a plurality of the metals Co, Cu, Ni, W and Mo. The invention further concerns a method for the production of these granulates and the use thereof. The production method is characterized in that a metal compound comprising one or a plurality of the groups comprising oxides, hydroxides, carbonates, hydrogenocarbonates, oxalates, acetates, formiates with binder and optionally in addition between 40 and 80% solvent, relative to the solids content, is granulated as the starting component, and the granulates are thermally reduced in a hydrogen-containing gaseous atmosphere to form the metal powder granulates, the binder and the solvent, if used, being removed completely.
Abstract: Tungstate solutions are purified by a precipitation process followed by two anion exchange processes to reduce molybdenum and arsenic impurity content. The precipitation involves acidification of the original highly basic tungstate solution to pH of 7 to 10 without addition of precipitating agents and separates out the bulk of impurities other than Mo, As. The first anion exchange process removes As. Then a remaining filtrate from the latter process is treated with sulfides to form thiomolybdates from impurity Mo content and the thiomolybdates are then separated out from the tungstate solution in a second anion exchange process.
Abstract: The performance of capacitor-grade tantalum powder that is vacuum packaged is enhanced. Preventing contact with air reduces the quantity of oxygen that passes through the oxide film and dissolves in the substrate. Lower oxygen in the powder can lower DC leakage in the capacitor made from the powder. Over a 4-month period, vacuum/argon packaging reduces oxygen pick-up in a 50K-class powder by over 200 ppm compared with the same powder stored in conventional packaging.
Type:
Grant
Filed:
June 7, 1995
Date of Patent:
June 27, 2000
Assignee:
H.C. Starck, Inc.
Inventors:
Ross W. Simon, Katsuo Iwabuchi, Hirobumi Ishikawa, Dieter Behrens
Abstract: The present invention relates to cobalt metal agglomerates consisting of peanut-shaped primary particles with average particle sizes in the range from 0.5 to 2 .mu.m, to a process for the production thereof and to the use thereof.
Type:
Grant
Filed:
April 24, 1998
Date of Patent:
February 1, 2000
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Astrid Gorge, Katrin Plaga, Armin Olbrich, Dirk Naumann, Wilfried Gutknecht, Josef Schmoll
Abstract: The present invention relates to cobalt metal agglomerates consisting of peanut-shaped primary particles, to a process for the production thereof and to the use thereof.
Type:
Grant
Filed:
November 21, 1997
Date of Patent:
January 18, 2000
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Astrid Gorge, Juliane Meese-Marktscheffel, Dirk Naumann, Armin Olbrich, Frank Schrumpf
Abstract: A method for the preparation of sodium tungstate by the oxidation of hard metal scrap and/or heavy metal scrap in a molten salt mixture of hydroxide and sodium sulfate.