Abstract: Process to decrease silicon content of metal powder produced by hydrogen reduction from ammoniacal ammonium sulphate solutions containing metal ammine complexes, wherein metal (Me) is Ni, Co, or Cu. The process controls the precipitation of metal hydroxide, which is found to be an effective scavenger for silicon. Silicon is preferentially removed from metal diammine sulphate-containing solutions by precipitating with a small amount of a metal hydroxide, and then separating the silicon-bearing metal hydroxide precipitate from the solution. This solution, from which the silicon impurity has been removed with the metal hydroxide precipitate, can then be reduced in one or more densification cycles with a reducing gas to produce an elemental metal powder having a decreased silicon content. Alternatively, the solution is reduced to produce a low silicon metal powder seed material for the first of the one or more densification cycles.

Abstract: The present application provides a method for fabricating hollow metal nano particles and hollow metal nano particles fabricated by the same.

Abstract: A method for producing nickel nanoparticles is described, including a first step of heating a mixture of a nickel carboxylate with 1-12 carbon atoms in its moiety excluding —COOH and a primary amine to obtain a complexed reaction solution with a nickel complex foiiiied therein, and a second step of heating the complexed reaction solution by a microwave to obtain a Ni-nanoparticle slurry. In the first step, the heating is preferably conducted at a temperature of 105-175° C. for 15 minutes or longer. In the second step, the heating is preferably conducted at a temperature of 180° C. or higher.

Abstract: A process for separating Co from Ni in an aqueous solution comprises subjecting the solution to extraction and using kinetic differences between Ni and Co in the extraction for achieving at least a partial separation of Co from Ni. This is effected by controlling the duration of the extraction so that a major portion of Co and a minor portion of Ni is extracted from the solution to produce a loaded extractant, enriched in Co and depleted in Ni compared to the feed solution, and a Co-depleted raffinate containing Ni. In a further embodiment, the invention utilizes kinetic differences between Ni and Co during striping for effecting separation of Ni and Co. The loaded extractant can be subjected to a bulk stripping or a selective stripping operation to obtain Co and Ni solutions from which Ni and Co can be recovered. The process may be incorporated in a hydrometallurgical process for the extraction of Ni and/or Co from an ore or concentrate containing Ni and Co.

Abstract: The invention addresses the problem of providing a method for producing microparticles. Provided is a method for producing microparticles. For the first process, seed microparticles are separated in a thin film fluid that forms between at least two processing surfaces, which are disposed facing each other, which can approach or separate from each other and at least one of which rotates relative to the other, and the fluid comprising the separated seed microparticles is discharged as a discharge fluid. Subsequently, for the second process, the separated seed microparticles are grown in the discharged discharge fluid to obtain the intended microparticles. Uniform and homogeneous micropartcles are obtained as a result of the microparticle producing method comprising the two process.

Abstract: A metal particle which is a non-nucleated, spherical porous material having continuous open pores, and which is formed from dendritic crystals which have grown uniformly outward from the center without requiring a nucleating agent. A method for producing a metal particle which includes the steps of: mixing a metal salt and a polycarboxylic acid in a liquid phase; adding a reducing agent to the resultant mixture to deposit metal particles; and drying the deposited metal particles. The metal particle produced by the method, which is a non-nucleated, spherical porous material having continuous open pores, is unlikely to suffer bonding or aggregation of the metal particles and exhibits excellent dispersibility, and, when the metal particle is used in a conductive composition, such as a conductive paste, a cured product having satisfactory conduction properties can be obtained at a relatively low temperature, making it possible to easily control the specific gravity or resistance.

Abstract: The invention relates to a method for leaching a material containing a valuable metal and precipitating the valuable metal as a fine-grained powder by changing the electrochemical potential of an intermediary metal in the solution. In the leaching stage the intermediary metal or substance of the electrolyte solution is at a high degree of oxidation and in the precipitation stage another electrolyte solution is routed into the solution, in which the intermediary metal or substance is at a low degree of oxidation. After the precipitation stage the solution containing the intermediary is routed to electrolytic regeneration, in which part of the intermediary is oxidised in the anode space back to a high potential value and part is reduced in the cathode space to its low value.

Abstract: Nickel-iron-zinc alloy nanoparticles of the present invention are in the form of tabular particles having a thickness of 1 ?m or less and an aspect ratio of 2 or more, wherein the (220) plane which is the crystal plane of the face-centered cubic lattice is oriented on the tabular surface of the particles.

Abstract: The invention relates to novel pre-alloyed metal powders a method for production and use thereof.

Abstract: The invention relates to a method and apparatus for controlling a continuous metal removal in conjunction with a zinc preparation process, in which the metal removal is performed in one or more reactors (11a-c), in conjunction with the reactor, the redox potential (16a-c) and the acidity and/or basicity are measured, and based on the measurement results, the process variables (17a-c) of the metal removal are adjusted towards the desired direction. According to the invention, the redox potential measurements (16a-c) are performed from the sludge produced in the reactor in conjunction with the outlet pipe of the reactor outside the reactor, and the measuring instrument (16a-c) is purified at predetermined intervals.

Abstract: A method of making metal nanostructures having a nanometer size in at least one dimension includes preparing an aqueous solution comprising a cation of a first metal and an anion, and mixing commercial elemental powder particles of an elemental second metal having a greater reduction potential than the first metal with the aqueous solution in an amount that reacts and dissolves all of the second metal and precipitates the first metal as metal nanostructures. The temperature and concentration of the aqueous solution and the selection of the anions and the second metal are chosen to produce metal nanostructures of a desired shape, for example ribbons, wires, flowers, rods, spheres, hollow spheres, scrolls, tubes, sheets, hexagonal sheets, rice, cones, dendrites, or particles.

Abstract: A method of forming stable nanoparticles comprising substantially uniform alloys of metals. A high dose of ionizing radiation is used to generate high concentrations of solvated electrons and optionally radical reducing species that rapidly reduce a mixture of metal ion source species to form alloy nanoparticles. The method can make uniform alloy nanoparticles from normally immiscible metals by overcoming the thermodynamic limitations that would preferentially produce core-shell nanoparticles.

Abstract: The invention relates to a method of making a nickel powder having an average particle size of less than about 100 nanometers, comprising contacting, at a temperature of about 50° C. to about 95° C., a reduction solution with a nickel solution to form a reaction mixture. The reduction solution comprises a base and a reducing agent. The nickel solution comprises a nickel compound water, a nucleation agent, a surfactant or dispersant, and combinations thereof. The yield of nickel nanoparticles is greater than about 90% relative to starting moles of nickel compound. The nickel powder is suitable for use in electronics applications and sintered metal applications.

Abstract: The invention relates to a method of making a nickel powder having an average particle size of less than about 100 nanometers, comprising contacting, at a temperature of about 50° C. to about 95° C., a reduction solution with a nickel solution to form a reaction mixture. The reduction solution comprises a base and a reducing agent. The nickel solution comprises a nickel compound water, a nucleation agent, a surfactant or dispersant, and combinations thereof. The yield of nickel nanoparticles is greater than about 90% relative to starting moles of nickel compound. The nickel powder is suitable for use in electronics applications and sintered metal applications.

Abstract: A method of forming an ink, including photochemically producing stabilized metallic nanoparticles and formulating the nanoparticles into an ink.

Abstract: Provided is a multi-layered ceramic capacitor including an internal electrode, the surface of which is smoothened and in which electrode breakage can be reliably prevented. Also provided are a conductive paste and a nickel powder or an alloy powder containing nickel as a main component, which are used in the multi-layered ceramic capacitor, and a method for manufacturing the powder. The nickel powder or the alloy powder containing nickel as a main component of the present invention has a spherical shape, a mean particle diameter D50 in the range of 10 to 300 nm, and a ratio (Dmax/D50) of a maximum particle diameter Dmax to the mean particle diameter D50 of 3 or less.

Abstract: The invention relates to a method for leaching a material containing a valuable metal and precipitating the valuable metal as a fine-grained powder by changing the electrochemical potential of an intermediary metal in the solution. In the leaching stage the intermediary metal or substance of the electrolyte solution is at a high degree of oxidation and in the precipitation stage another electrolyte solution is routed into the solution, in which the intermediary metal or substance is at a low degree of oxidation. After the precipitation stage the solution containing the intermediary is routed to electrolytic regeneration, in which part of the intermediary is oxidised in the anode space back to a high potential value and part is reduced in the cathode space to its low value.

Abstract: A method of forming bimetallic core-shell metal nanoparticles including a core of a first metal material and a shell of a second metal material, the method including photochemically producing metallic nanoparticle cores of the first metal material, and forming a shell of the second metal material around the cores. The shell can be formed by adding shell-forming precursor materials to a solution or suspension of the cores and photochemically forming the shells around the cores, or by separately photochemically producing metallic nanoparticles of the second metal material and mixing the metallic nanoparticles of the second metal material and the metallic nanoparticle cores to cause the metallic nanoparticles of the second metal material to form a shell around the metallic nanoparticle cores.

Abstract: A method for generating metallic nanomaterials using acetylenic-bridged metal-carbonyl complexes as a precursor allows control of nanoparticle properties. The novel method produced metallic nanomaterials resistant to oxidation.

Abstract: A melt of nickel nitrate hydrate is introduced as droplets or liquid flow into a heated reaction vessel and thermally decomposed in a gas phase at a temperature of 1200° C. or more and at an oxygen partial pressure equal to or below the equilibrium oxygen pressure of nickel-nickel oxide at that temperature to manufacture a highly crystalline fine nickel powder with an extremely narrow particle size distribution. The oxygen partial pressure during the thermal decomposition is preferably 10?2 Pa or less, and a metal other than nickel, a semimetal and/or a compound of these may be added to the nickel nitrate hydrate melt to manufacture a highly crystalline nickel alloy powder or highly crystalline nickel composite powder. The resultant powder is suited in particular to thick film pastes such as conductor pastes for manufacturing ceramic multilayer electronic components.

Abstract: Provided is a method for preparing nickel nanoparticles capable of easily controlling particle sizes and shapes of the nickel nanoparticles and obtaining a high yield of the nickel nanoparticles using a process that is simpler than methods used to mass-produce the nickel nanoparticles. The method for preparing nickel nanoparticles may be useful to prepare nickel nanoparticles by mixing a nickel precursor and organic amine to prepare a mixture and heating the mixture.

Abstract: A method of manufacturing nickel nanoparticles and nickel nanoparticles thus produced, having superior dispersion stability and smooth surface, by reducing after forming nickel-hydrazine complex in a reverse microemulsion, where the method includes forming an aqueous solution including nickel precursor, surfactant, and hydrophobic solvent, forming nickel-hydrazine complex by adding a reducing agent that includes hydrazine to the mixture, and producing nickel nanoparticles by adding a reducing agent to the mixture that includes the nickel-hydrazine complex.

Abstract: A method of forming an ink, including photochemically producing stabilized metallic nanoparticles and formulating the nanoparticles into an ink.

Abstract: An efficient process for producing fine nickel powder, capable of metallizing the powder at low temperature to prevent its sintering, and fine nickel powder produced by the process, composed of particles having a flat shape, diameter of limited variations and uniform thickness, and suitable for internal electrodes for laminate ceramic capacitors of high electric capacity. The process comprises a step for forming a nickel compound coated with gelatin by adsorbing gelatin on preformed nickel compound particles with different size and shape (Step (A)), and another step for converting said nickel compound coated with gelatin into fine particles containing metallic nickel and nickel oxide by heating the nickel compound coated with gelatin produced in Step (A) in an inert gas atmosphere (Step (B)). It may include an additional step (Step (C)), subsequent to Step (B), for completely reducing nickel oxide in said fine particles by heating at temperature lower than that for Step (B) in a reducing gas atmosphere.

Abstract: Glycerol is used as a solvent medium for the precipitation of a complex of nickel and glycerol material. The precipitate is separated from the liquid solvent and dried and calcined in air to produce small (nanometer size) particles characterized by a nickel core encased in a nickel oxide shell. The proportions of nickel core and nickel oxide shell can be controlled by management of the time and temperature of heating in air. Prolonged heating in air can produce nickel oxide particles, or calcining of the precipitate in nitrogen produces nickel particles.

Abstract: There is provided a method of preparing nano scale nickel powders by wet reducing process. An embodiment of the method of preparing nickel powders comprises preparing the first solution formed by mixing water and a base, preparing the second solution formed by mixing a polyol and a nickel compound, preparing a mixture by mixing the first solution and the second solution, heating the mixture, and separating the nickel powders generated during heating.

Abstract: A process for producing sub-micron-sized copper powder comprising the steps of: providing a precursor composition comprising a solution of copper monoethanolamine complex; and heating the precursor composition to a temperature wherein copper monoethanolamine complex is converted to copper powder. A process for producing nickel powder comprising the steps of: providing a precursor composition comprising a solution of nickel monoethanolamine complex; and heating the precursor composition to a temperature wherein nickel monoethanolamine complex is converted to nickel powder.

Abstract: The present invention relates to a method for manufacturing nickel nanoparticles and more particularly to a method including preparing a mixture solution by adding a reducing agent, a dispersing agent and a nickel salt to a polyol; stirring and heating the mixture solution; and producing nickel nanoparticles by reacting the mixture solution, so that it allows mass production of nickel nanoparticles having uniformity of size 30 to 50 nm and high dispersibility.

Abstract: The invention provides a powder of fine particles of an alloy of platinum-family metal having a surface with a large amount of unevenness that is suitable as a catalyst metal. It is a powder of an alloy containing T and M in a composition ratio represented by the formula [TXM1?X], where T is one or two or more of the elements Fe, Co and Ni, M is one or two or more of the elements Pt, Pd and Ru, X represents a numerical value in the range 0.1-0.9, and wherein: its average grain size as measured under TEM observation (DTEM) is 50 nm or less, and under TEM observation, a plurality of protruding points is observed on the surface of the particles and indentations are observed between the protruding points, making it a fine powder of alloy particles with an uneven surface. This powder of fine alloy particles has a crystal structure with a face-centered cubic (fcc) structure, and its single crystallinity (DTEM)/(DX) is 1.50 or greater.

Abstract: Provided are non-magnetic nickel powders and a method for preparing the same. The nickel powders have non-magnetic property and a HCP crystal structure. The method include (a) dispersing nickel powders with a FCC crystal structure in an organic solvent to prepare a starting material dispersion, and (b) heating the starting material dispersion to transform the nickel powders with the FCC crystal structure to the nickel powders with the HCP crystal structure. The nickel powders do not exhibit magnetic agglomeration phenomenon. Therefore, the pastes for inner electrode formation in various electronic devices, which contain the nickel powders of the present invention, can keep the well-dispersed state. Also, inner electrodes made of the nickel powders can have a low impedance value even at high frequency band.

Abstract: A hydrogen storage battery with improved cycle life and a method for making the same. The battery has a negative electrode with an electrochemically active negative material and a negative electrode capacity and a positive electrode electrochemically coupled with the negative electrode, the positive electrode having a positive electrode capacity and an electrochemically active positive material with a precharge. Also described herein is a positive electrode material for a hydrogen storage battery and a method for making the same. The positive electrode material includes a preoxidized positive active material which is partially non-oxidized. The preoxidized positive material may be used to provide precharge to the positive electrode of a hydrogen storage battery to aid in cell balancing.

Abstract: A method of manufacturing the chain-structure metal powder comprises precipitating a metal powder by a reaction performed in an aqueous solution in which nickel ions, complex ions, and titanium ions containing trivalent titanium ions (Ti3+) and tetravalent titanium ions (Ti4+) are present.

Abstract: Provided are a method for preparing metallic nickel powders capable of decreasing the content of an alkaline metal in the metallic nickel powders, metallic nickel powders with the low content of an alkaline metal, a conductive paste including metallic nickel powders with the low content of an alkaline metal, and a multi-layer ceramic capacitor (MLCC) including a nickel inner electrode with the low content of an alkaline metal. The method for preparing the metallic nickel powders includes heating a mixture including an organic base, a nickel precursor compound, and a polyol. Wherein, the nickel precursor compound is converted to the metallic nickel powders through reduction by the organic base and the polyol. In the method, the organic base is used instead of the hydroxide of an alkaline metal such as NaOH and KOH. Therefore, the content of an alkaline metal such as sodium and potassium that can be incorporated as an impurity into the metallic nickel powders can be significantly reduced.

Abstract: Provided is a method for preparing non-magnetic nickel powders. The method include (a) heating a mixture including a nickel precursor compound and a polyol to reduce the nickel precursor compound to nickel powders with a face-centered cubic (FCC) crystal structure, and (b) heating the resultant mixture of step (a) to transform at least a portion of the nickel powders with the FCC crystal structure to nickel powders with a hexagonal close packed (HCP) crystal structure.

Abstract: There is provided a nickel powder suitable as conductive particles for use in conductive paste and conductive resin, that is inexpensive, has superior weather resistance, low resistivity when kneaded with resin, and is stable when used in the long-term, and a production method therefor. A nickel powder is produced by a two stage reduction and precipitation process from an aqueous solution containing a bivalent nickel salt, wherein an average primary particle diameter is 0.2 ?m to 2.0 ?m as measured with a scanning electron microscope (SEM), wherein an average secondary particle diameter is 8 ?m to 50 ?m according to laser particle size distribution measurement, wherein a tap density is 0.5 g/ml to 2.0 g/ml, wherein a cobalt content is 1 to 20 weight %. The cobalt may be contained in only the surface layer of the nickel powder at a content of 1 weight % to 40 weight %.

Abstract: A composite substance for forming a conductive paste, comprises a solvent and metal or metal compound particles. The solvent is compatible with an organic component included in the conductive paste, and the metal or metal compound particles are dried metal or metal compound particles having the second solvent adhering to the surface thereof. The conductive paste comprises an organic vehicle, a solvent, and the composite substance which is mixed with the organic vehicle and the solvent. The method for manufacturing the composite substance comprises the steps of washing metal or metal compound particles with water, adding a solvent that is compatible with an organic component included in the conductive paste, thereby replacing water components, and drying the metal or metal compound particles having the solvent adhering to the surface thereof.

Abstract: Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Abstract: Metal chloride vapor and reducing gas are brought into contact to form metallic powder, the metallic powder is washed in carbonic acid aqueous solution, and the metallic powder is classified in a liquid phase. In this way, metallic powder, such as nickel powder, in which the content of chloride components is extremely small and the coarse particle content is small, can be efficiently produced.

Abstract: A metal powder composed of nickel or an alloy thereof and used for a producing a conductivity-afforded material is provided, in which particles are integrated in particle aggregates having a chain structure. The average diameter of the particle aggregates is in the range of 30 to 200 nm, and the average length thereof is in the range of 0.5 to 50 &mgr;m. The increased conductivity bestowing effect can be obtained by the addition of a small amount of the metal powder.

Abstract: The invention relates to a method for the precipitation of nickel from an aqueous solution containing its sulphate as a metallic powder suitable as an alloying element for refined steel. In this method, nickel reduction takes place continuously in one or several autoclaves at a temperature of 80-180 ° C. and hydrogen pressure of 1-20 bar, whereby the production capacity can be raised significantly, compared to batch processes made in correspondingly dimensioned devices or equipment.

Abstract: The present invention relates to a process for recovery of nickel and alumina from spent catalyst by direct leaching with sulphuric acid in presence of small amount of an additive. The invention is useful for recovery of both nickel and sources of nickel and therefore important from the view of environmental protection, resource recycling and conservation.

Abstract: Ultrafine composite metal particles comprising a surfactant sheath and an organic compound sheath that surround a metal core in which metal atoms obtained by reduction precipitation from an organic metal compound have agglomerated, the particle diameter being 1 to 100 nm. The ultrafine composite metal particle may comprise a surfactant sheath that surrounds a metal core in which metal atoms obtained by reduction precipitation from an inorganic metal compound have agglomerated. The ultrafine composite metal particles are obtained by forming an ultrafine particle precursor by producing a colloidal solution of an organic metal compound or an inorganic metal compound in a nonaqueous solvent using a surfactant, and by reducing the ultrafine particle precursor by adding a reducing agent to this colloidal solution, thus forming ultrafine composite metal particles with a diameter of 1 to 100 nm and having at least a surfactant sheath around a metal cored.

Abstract: The invention relates to a method for the precipitation of nickel from an aqueous solution containing its sulphate as a metallic powder suitable as an alloying element for refined steel. In this method, nickel reduction takes place continuously in one or several autoclaves at a temperature of 80-180° C. and hydrogen pressure of 1-20 bar, whereby the production capacity can be raised significantly, compared to batch processes made in correspondingly dimensioned devices or equipment.

Abstract: The invention relates to a method for the precipitation of nickel from its aqueous solution as a metal powder using hydrogen. The aqueous solution containing nickel compounds is neutralised first with an earth alkali or alkali compound so the nickel precipitates as nickel hydroxide or as an alkaline salt, after which reduction is performed in the presence of a catalyst in ion form in atmospheric or close to atmospheric conditions preferably as a continuous process.

Abstract: Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Abstract: The nickel powder is characterized in that the rate of the nickel particles whose particle size is not less than 1.2 time the average particle size as determined by the observation with an SEM is not more than 5% of the total number of nickel particles and that the rate of nickel particles whose particle size is not more than 0.8 time the average particle size is not more than 5% of the total number of nickel particles. The nickel powder is produced by bringing a slurry, containing nickel hydroxide, which is prepared by adding an aqueous solution of a nickel salt to an aqueous solution of an alkali metal hydroxide, into contact with a hydrazine reducing agent under the temperature conditions of not less than 55° C. to reduce the nickel hydroxide.

Abstract: A metal powder is formed by the steps of preparing a reducing agent solution, preparing a mixed metallic salt solution by dissolving a nickel salt and a copper salt in a solvent, and mixing the reducing agent solution and the mixed metallic salt solution so that the copper salt is reduced to precipitate copper particle nuclei and then the nickel salt is reduced to precipitate nickel around the copper particle nuclei. A metal power produced by this production method, a conductive paste containing the metal powder and a monolithic ceramic electronic component in which internal electrodes are formed using the conductive paste are also disclosed.

Abstract: A high-surface-area heterogenite (HCoO2) material is described for use in making submicron cobalt metal powders. The HCoO2 material has a surface area of at least about 90 m2/g and is preferably produced by dehydrating a cobalt hydroxide precipitate at 110° C.

Abstract: Provided is an ultrafine nickel powder suitable for a laminated ceramic capacitor electrode material. According to the ultrafine nickel powder, cracks and/or delamination are not liable to generate in the process for producing a ceramic capacitor, and its internal electrode can be made into a thinner layer, and the electric risistivity of the capacitor can be made low. The ultrafine nickel powder has an average particle size of 0.1-1.0 &mgr;m, having the sulfur content of 0.02-1.0% by weight, and particles thereof being spherical, thereby exhibiting excellent properties. They can be produced by vapor phase hydrogen-reducing process using nickel chloride vapor.

Abstract: A process for the production of fine powder of metallic nickel which comprises a first step of dissolving nickel carbonate and/or nickel hydroxide in aqueous ammonia or in an aqueous solution of ammonia and at least one selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, a carbonate of an alkali metal and a hydrogencarbonate of an alkali metal to prepare an aqueous solution of a nickel salt; converting the aqueous solution of a nickel salt to a W/O emulsion, and then removing volatile components including ammonia from the droplets to form precipitates of nickel carbonate in the droplets, thereby providing fine spherical particles of nickel carbonate; and a second step of heating the particles of nickel carbonate in the presence of a fusion preventive agent that is a compound of at least one element selected from the group consisting of alkaline earth elements, aluminum, silicon and rare earth elements in an atmosphere of hydrogen, thereby reducing the nickel carbonate to meta