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: 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: 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 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.
Abstract: An intermetallic nickel-aluminum base alloy has a microstructure which predominantly includes the binary phase NiAl and further contains the elements chromium and tantalum. The content of the elements chromium and tantalum is in total at most 12 atom %. Preferred contents ranges are 0.3 to 3.8 atom % tantalum and 1.0 to 9.0 atom % chromium. The intermetallic nickel-aluminum base alloy is distinguished in particular by high oxidation resistance at high temperatures, such as for example 1350.degree. C. It is therefore suitable for producing components which are exposed to a high long term temperature stress such as, for example, gas turbine blades. Depending on requirements, additional layers protecting against oxidation can be dispensed with due to the high oxidation resistance.
Type:
Grant
Filed:
November 21, 1996
Date of Patent:
August 10, 1999
Assignees:
Siemens Aktiengesellschaft, H. C. Starck GmbH & Co. KG
Abstract: The present invention relates to novel organometallic compounds of the general formula M(OH).sub.y (A).sub.V (B).sub.z, wherein M is Ti(IV), Nb(V) or Ta(V) and x +y+z=5 for Nb and Ta and x+y+z=4 for Ti and A means an alkoxide ligand of diols and/or glycol monoethers and B is a carboxylate ligand of fatty acids of a carbon chain length of C.sub.6 -C.sub.19, and to processes for the production and use thereof.
Type:
Grant
Filed:
June 3, 1997
Date of Patent:
June 22, 1999
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Karlheinz Reichert, Wolfgang Simon, Harald Troger, Gisbert Ebeling
Abstract: The present invention relates to a process for removing antimony from hydrofluoric acid solutions which contain Ta/Nb and have an acidity of >18 N, by addition of a base metal reducing agent to the solution and heating at 40 to 60.degree. C. for 4 to 8 hours.
Type:
Grant
Filed:
April 30, 1997
Date of Patent:
June 1, 1999
Assignee:
H.C. Starck GmbH & Co KG
Inventors:
Walter Bludssus, Karlheinz Reichert, Uwe Bohmke
Abstract: Method of preparing metal disulfides of the general formula(Sn.sub.x Me.sub.1-x)S.sub.2,whereinMe represents one or more of the elements Ti, Mo, Fe, Cr, Ta, Nb, Mn, Bi, W and Cu, andx can have values between 0.5 and 1,by mixing Sn, alone or with Me and/or Me sulfides, with a superstoichiometric quantity of S and reacting the same together, in the presence of halide compounds, in an exothermic reaction in an inert atmosphereand the further processing the disulfide product thereof to form dimetal trisulfides.
Abstract: The present invention relates to a process for the production of pure ammonium metallates of the metals W, Mo, V, Cr and Re, wherein alkaline metal salt solutions are adjusted to a pH value in the range from 5 to 9 by reaction with CO.sub.2, these metal salt solutions are passed through an anion exchanger in carbonate form, wherein, in addition to the alkali metal carbonate solution, the metallate form of the ion exchanger is formed, the ion exchanger is then washed until free of alkali and is then eluted by means of aqueous ammonia to form ammonium metallate solutions and the anion exchanger in the OH form, wherein the anion exchanger is converted into the carbonate form by means of CO.sub.2 treatment and is recycled.
Abstract: Phase-pure, crystalline tungstates of general composition Me(II)WO.sub.4, where Me(II)=Co, Ni, Zn, Pb, Mg, Ca, Sr and/or Ba. These are prepared by wet mixing tungsten components (preferably ammonium paratungstate or metatungstate) with corresponding sponding Me(II) oxides and used, preferably, in making perovskites and X-ray intensifier phosphors.
Type:
Grant
Filed:
May 9, 1995
Date of Patent:
February 23, 1999
Assignee:
H.C Starck GmbH & Co. KG
Inventors:
Walter Bludssus, Karlheinz Reichert, Udo Sulkowski
Abstract: The present invention relates to pastes for the coating of substrates, consisting of powdery materials present in liquid dispersion from the group of the metals, metal compounds and/or metal alloys and/or boron and/or carbon, methods for manufacturing them and their use.
Type:
Grant
Filed:
October 16, 1996
Date of Patent:
March 3, 1998
Assignee:
H.C. Starck GmbH & Co., KG
Inventors:
Bruno E. Krismer, Uwe Thies, Peter Ladstatter, Rudolf Hunert
Abstract: Highly reactive metal niobates and/or metal tantalates of the general formula Me(II)A.sub.2 O.sub.6 or Me(III)AO.sub.4, a method for the preparation thereof, their further processing to form perovskites of the general formula X(B'B")O.sub.3 wherein X signifies Pb and/or Ba, B' signifies Mg, Fe, Co, Ni, Cr, Mn, Cd, Ti, Zr and/or Zn and B" signifies Nb and/or Ta, as well as these perovskites are provided through the present invention. An additive of Li, Na and/or K is provided to the niobates/tantalates in 0.1 to 20 mol-%.
Abstract: Cobalt/cobalt oxide powder having the composition Co.sub.x (CoO).sub.1-x, where x is from 0.02 to 5, and a process for its production and use in nickel hydroxide electrodes for secondary batteries to enhance capacity.