Abstract: The invention is directed to ammonium paratungstate decahydrate containing at least 75% of crystals having a length of at least 200 ?m and having a ratio of length to width of less than 4.5:1.
Type:
Grant
Filed:
May 29, 2012
Date of Patent:
May 14, 2013
Assignee:
H. C. Starck GmbH
Inventors:
Viktor Stoller, Michael Erb, Juliane Meese-Marktscheffel, Michael Lohse, Klaus-Jürgen Marschall, Frank Schrumpf
Abstract: A method for preparing ammonium heptamolybdate with the steps of: i) adding a molybdenum-containing organic phase to a liquid-liquid reextraction apparatus or to a desorption apparatus, and ii) directly cold-crystallization ammonium heptamolybdate by cooling the resulting reextraction or desorption solution.
Type:
Grant
Filed:
January 29, 2008
Date of Patent:
April 30, 2013
Assignee:
H.C. Starck GmbH
Inventors:
Viktor Stoller, Michael Erb, Juliane Meese-Marktscheffel, Benno Decker
Abstract: A dispersion comprising hard material particles and at least one organic binder and/or at least one plasticizer. The hard material particles comprise an inner core comprising a fused tungsten carbide and an outer shell comprising tungsten carbide.
Abstract: A process for digesting molybdenum oxide concentrates includes suspending a molybdenum-containing starting material in an aqueous solution so as to obtain a suspension. While stirring, an oxidizing agent and an alkali solution of at least one alkali metal are metered to the suspension so as to set a pH and produce a product having a molybdenum content of at least 98% of the molybdenum-containing starting material. The alkali metal is selected from the group consisting of Na, K and Li.
Type:
Grant
Filed:
November 4, 2008
Date of Patent:
February 26, 2013
Assignee:
H. C. Starck GmbH
Inventors:
Josef Schmoll, Brigitte Schimrosczyk, Gisbert Ebeling, Joerg Henze
Abstract: The invention relates to a pulverulent zirconium oxide containing metal oxides from the group consisting of scandium, yttrium, rare earths and mixtures thereof, processes for producing them and their use in fuel cells, in particular for the production of electrolyte substrates for ceramic fuel cells.
Type:
Grant
Filed:
July 24, 2007
Date of Patent:
February 26, 2013
Assignee:
H.C. Starck GmbH
Inventors:
Jörg Laube, Alfred Gügel, Ralph Otterstedt
Abstract: The invention is directed to ammonium paratungstate decahydrate containing at least 75% of crystals having a length of at least 200 ?m and having a ratio of length to width of less than 4.5:1.
Type:
Application
Filed:
May 29, 2012
Publication date:
January 31, 2013
Applicant:
H.C. Starck GmbH
Inventors:
Viktor Stoller, Michael Erb, Juliane Meese-Marktscheffel, Michael Lohse, Klaus-Jürgen Marschall, Frank Schrumpf
Abstract: A method for producing a workpiece comprising a layer of an additive-free silicon nitride includes providing a base body of the workpiece. A layer of a slip comprising a silicon powder is applied to an inside of the base body so as to obtain a coated base body. The coated base body is subjected to a reactive firing under nitrogen so as to convert the silicon powder to the additive-free silicon nitride.
Abstract: A niobium suboxide powder comprising niobium suboxide particles having a bulk nitrogen content of between 500 to 20,000 ppm. The nitrogen is distributed in the bulk of the powder particles. The nitrogen at least partly is present in the form of at least one of Nb2N crystals or niobium oxynitride crystals.
Type:
Application
Filed:
May 9, 2012
Publication date:
September 27, 2012
Applicant:
H.C. STARCK GMBH
Inventors:
CHRISTOPH SCHNITTER, Holger Brumm, Christine Rawohl, Colin McCracken
Abstract: The invention relates to a method of recovering molybdenum from a molybdenum bearing sulfide material. The material is contacted with a leaching solution in the presence of iron compounds and mesophilic or thermophilic iron oxidizing microorganisms and subsequently, a leaching process is performed by controlling the molar ratio of dissolved ferric iron to dissolved molybdenum. Preferably, a high amount and molar excess of dissolved iron is used. The presence of high concentrations of ferric iron in bioleach solutions allows iron-oxidizing microorganisms to grow and oxidize iron and bioleach molybdenite at dissolved Mo concentrations as high as 4.4 g/L. Organic metabolites were not required for protecting cells from Mo toxicity. Maximum dissolution rates depend on reactor configuration, with agglomerated material simulating heap leaching of almost 1% Mo/day, but up to 10.2% Mo/day in suspension/stirred reactor configurations, with rate highly dependent on temperature within the range of 25° C. to 40° C.
Type:
Grant
Filed:
July 19, 2007
Date of Patent:
September 18, 2012
Assignee:
H.C. Starck GmbH
Inventors:
Wolfgang Kummer, Wilfried Gutknecht, James Gregory Olson, Thomas R. Clark
Abstract: The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner.
Type:
Grant
Filed:
November 12, 2010
Date of Patent:
July 24, 2012
Assignee:
H.C. Starck GmbH
Inventors:
Viktor Stoller, Michael Erb, Juliane Meese-Marktscheffel, Michael Lohse, Wolfgang Mathy
Abstract: The invention is directed to a process for the continuous preparation of ammonium paratungstate hydrate by back reextraction of a tungsten-laden organic phase with an ammonia-containing aqueous solution in a mixer-settler apparatus. The reextraction is carried out at an NH3:W molar ratio of from 0.83 to 1.30, and a volume feed ratio of the tungsten-laden organic phase to the ammonia-containing aqueous solution of from 5 to 25. The above crystalline is in high purity and in high yield. The production method can be carried out in a simple and energy-efficient manner.
Type:
Grant
Filed:
January 29, 2008
Date of Patent:
July 10, 2012
Assignee:
H.C. Starck GmbH
Inventors:
Viktor Stoller, Michael Erb, Juliane Meese-Marktscheffel, Michael Lohse, Klaus-Jürgen Marschall, Frank Schrumpf
Abstract: In various embodiments, sputter-target formation includes application of a layer having an intermediate coefficient of thermal expansion between the backing plate and the target material.
Type:
Grant
Filed:
November 8, 2007
Date of Patent:
June 12, 2012
Assignees:
H.C. Starck GmbH, H.C. Starck Inc.
Inventors:
Steven A. Miller, Olaf Schmidt-Park, Prabhat Kumar, Richard Wu, Shuwei Sun, Stefan Zimmermann
Abstract: Disclosed is a niobium suboxide powder for the manufacture of capacitors with higher break down voltages, higher temperatures of operation and elongated lifetimes. The powder is doped with nitrogen which is at least partly present in the form homogeneously distributed, x-ray detectable Nb2N-crystal domains. The niobium suboxide powder contains niobium suboxide particles having a bulk nitrogen content of between 500 to 20,000 ppm.
Type:
Grant
Filed:
May 31, 2006
Date of Patent:
May 29, 2012
Assignee:
H. C. Starck GmbH
Inventors:
Christoph Schnitter, Holger Brumm, Christine Rawohl, Colin McCracken
Abstract: The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner.
Type:
Grant
Filed:
January 29, 2008
Date of Patent:
May 1, 2012
Assignee:
H.C. Starck GmbH
Inventors:
Viktor Stoller, Michael Erb, Juliane Meese-Marktscheffel, Michael Lohse, Wolfgang Mathy
Abstract: The invention relates to a process for the production of electrolyte capacitors having a low equivalent series resistance and low residual current, electrolyte capacitors produced by this process and the use of such electrolyte capacitors.
Type:
Application
Filed:
October 6, 2011
Publication date:
March 29, 2012
Applicant:
H.C. Starck GmbH
Inventors:
Udo Merker, Wilfried Lövenich, Klaus Wussow, Ralph Tillmann
Abstract: Process for the production of a powdered spherical tungstic acid by acidification of an aqueous alkaline tungstate solution with mineral acid at elevated temperature, preferably in a continuous stirred tank or a cascade of at least 2 continuous stirred tanks, and tungstic acid obtainable in this way, which is characterised by a high bulk density and spherical morphology.
Type:
Application
Filed:
September 23, 2011
Publication date:
February 23, 2012
Applicant:
H.C. Starck GmbH
Inventors:
Sven Albrecht, Armin Olbrich, Michael Reib, Frank Schrumpf, Juliane Meese-Marktscheffel, Uwe Kutzler
Abstract: A crucible for producing a silicon suitable for producing a semiconductor includes a plurality of components and at least one unclosed joint gap.
Abstract: A process for producing a solid electrolyte capacitor with an anode comprising a sintered fine NbOx powder, where 0.5<x<1.7, includes providing a green anode body. The green anode body is sintered so as to provide a sintered anode body. The sintered anode body is formed so as to provide a formed anode body, wherein the forming is essentially performed without applying a pressure. The formed anode body is provided with a cathode so as to provide the solid electrolyte capacitor.