Abstract: It is possible to recover gallium and indium efficiently and at a low cost from solutions containing traces of gallium and indium. In particular, jarosite is produced by performing a specific treatment on a solution obtained by a two-stage neutralization treatment during the zinc leached residue treatment step of wet zinc refining, or on another solution containing traces of gallium and indium; the gallium and indium are separated and concentrated; an alkali is added to the jarosite; and the gallium is separated and concentrated by leaching. Calcium hydroxide or magnesium hydroxide is optionally added to the jarosite leached solution to perform purifying, sulfuric acid is added to the purified solution, neutralization is performed, basic gallium sulfate is precipitated, the precipitate is subjected to alkali leaching, and the gallium in the leached solution is electrolytically extracted, yielding metallic gallium.

Abstract: A permanent magnet alloy having an improved heat resistance comprising, in terms of % by atom, 0.1 to 15 at. % C, 0.5 to 15 at. % B, provided that C and B in total account for 2 to 30 at. %; 40% or less Co (exclusive), 0.5 to 5 at. % in total of Dy and Tb, 8 to 20 at. % R. where R represents at least one element selected from the group consisting of Nd, Pr, Ce, La, Y, Gd, Ho, Er, and Tm; with the balance being Fe and unavoidable impurities.

Abstract: A magnetic material made up of an assembly of particles substantially consisting of an &agr;″-Fe16N2 crystal having a body-centered tetragonal system (bct). The magnetic material has a high saturated magnetic flux density and is directly synthesized by reacting fine particles of &agr;-Fe and a nitrogen-containing gas at a temperature of 200° C. or lower. By the synthesis of this invention, &agr;″-Fe16N2, which is a metastable compound conventionally deposited accompanied with phase transformation of crystallization from a martensite phase of &agr;′-Fe(N), is obtained as an isolated bulk substance in a single phase.

Abstract: A process for the production of copper or a copper base alloy that provides a surface having improved characteristics suitable for the production of a connector or a charging-socket of an electric automobile by having a decreased coefficient of friction on the surface and improved resistance to abrasion. The process comprises coating copper or a copper alloy with Sn, followed by heat treating the resulting Sn-plated copper or copper base in an atmosphere having an oxygen content of no more than 5%, thereby forming on an outermost surface thereof an oxide film and beneath the surface a layer of an intermetallic compound mainly comprising Cu—Sn.

Abstract: Fluorocarbons including perfluorocarbons and hydrofluorocarbons are highly efficiently decomposed by contacting a gaseous fluorocarbon with a reagent comprising carbon and an alkaline earth metal or carbon, an alkaline earth metal and an alkali metal at an elevated temperature, the decomposed halogen being fixed to the reagent.

Abstract: The novel apparatus for producing high-purity silver comprises an electric furnace 1, an outer cylinder 3 contained in the furnace in such a way that it can be evacuated with a vacuum pump 2, a feed crucible 5 placed within the outer cylinder 3 and fixed onto an aspiration table 9 provided in the center of a recovery mold 6, a cooling trap 8 and a water-cooled flange 7 that are detachably connected to the other parts including an inner cylinder 4 located over the crucible 5. When a silver feed is heated within the crucible at 3a specified temperature and pressure, the silver evaporates and condenses on the ceiling of the inner cylinder to yield silver particles, which are collected in the recovery mold; gold, copper and other impurities having higher vapor pressures than silver are left within the crucible whereas sulfur, sodium and other impurities having higher vapor pressures are withdrawn by means of the vacuum pump to be introduced into the cooling trap and hereafter solidified.

Abstract: Metallic zinc melted to a purity of 99.995% or higher was treated with selected elements that were dissolved in amounts within specified ranges and the resulting melts were atomized to prepare zinc alloy powders of 35-200 mesh; the powders were gelled with a gelling agent (sodium polyacrylate) and an electrolyte; bismuth compounds having specified powder characteristics (either an average particle size of no more than 10 &mgr;m or a specific surface area of at least 1 m2/g or both characteristics) were added in specified amounts to the gels, thereby producing gels of anode.

Abstract: A copper alloy for terminals of the Cu—Ni—Sn—P system or Cu—Ni—Sn—P—Zn system and that has a tensile strength of at least 500 N/mm2, a spring limit of at least 400 N/mm2, a stress relaxation of no more than 10%, a conductivity of at least 30% IACS and a bending workability in terms of a R/t ratio of no more than 2. The spring portion or the entire part of such terminals are produced from the copper alloy, and have an initial insertion/extraction force of 1.5 N to 30 N and a resistance of no more than 3 m&OHgr; at low voltage and low current as initial performance. The terminals experience not more than 20% stress relaxation.

Abstract: A copper powder is provided that has an average particle diameter in the range of from not less than 0.1 &mgr;m to less than 1.5 &mgr;m, that has a narrow particle size distribution width whose value A defined by Equation (1) below in terms of X25, X50 and X75 defined below is not greater than 1.2, and that forms a pseudo-fused sintered product when held at a temperature of 800° C.

Abstract: A process for producing a high-purity silver material comprising placing a silver feed in a crucible disposed in a furnace comprising an inner cylinder which encloses the crucible and an outer cylinder which encloses the inner cylinder; heating the silver feed at a temperature not lower than 1065° C. and at a pressure not higher than 0.1 Pa such that the silver evaporates and condenses on the ceiling of the inner cylinder to yield silver particles; and collecting silver particles in a recovery mold disposed beneath the crucible and within the inner cylinder, such that gold, copper and other impurities having a lower vapor pressure than silver remain within the crucible, whereas sulfur, sodium and the other impurities having a higher vapor pressure than silver are withdrawn by a vacuum pump and are then introduced into a cooling trap disposed beneath the recovery mold, such that the higher vapor pressure impurities are solidified in the cooling trap.

Abstract: In a copper flash-smelting works, forced oxidation of dust is prevented, adhesion of dust to a boiler water tube is reduced, and on-line ratio and productivity index is improved. The temperature at the WHB radiation section outlet is greatly reduced and the atmosphere within the WHB radiation section is controlled by blowing the mixed gas of nitrogen gas and air from the feed aperture established in the wall into the boiler radiation section of the waste heat boiler of the flash-smelting furnace in a copper flash-smelting works.

Abstract: An electrolytic refining method for gallium by depositing refined gallium on a cathode in an electrolytic solution using a melted raw gallium material as an anode in an electrolytic cell is disclosed, comprising applying a centrifugal force to the melted raw gallium material and discharging out a scum gathered in the central portion of the cell.

Abstract: Low-cost, high-purity strontium nitrate that is low in Ba, Na, Ca, Cr, and other impurities and that is suitable for use in airbags or the like is provided. High-purity strontium nitrate having a Ba content of 0.01 wt % or lower, an Na content of 0.005 wt % or lower, a Ca content of 0.01 wt % or lower, a Cr content of less than 0.001 wt %, and a purity of 99.5 wt % or higher is produced by a manufacturing method comprising a first step for performing crystallization by adding nitric acid to an aqueous solution obtained by dissolving a strontium compound as a starting material, a second step for separating the resulting crystals, a third step for crystallizing the resulting separated solution, and a fourth step for separating the resulting crystals.

Abstract: In the present invention, a metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0˜99.5% of an Ag powder, 0˜9.5% of a Cu powder and 0.5˜4.0% of an active metal powder, and 0.0˜0.9% of a titanium oxide powder if necessary.

Abstract: An oxide superconductor current lead provided with a rod-like or pipe-like oxide superconductor, at each of end parts of which a metallic electrode is formed. In this oxide superconductor current lead, the oxide superconductor is a Bi2Sr2Ca2Cu3OX superconductor. Further, the metallic-electrode-portion contact resistivity thereof is not more than 0.05 &mgr;&OHgr;·cm2. Moreover, the critical current density is not less than 2,000 A/cm2. Furthermore, there is provided a method of manufacturing such an oxide superconductor current lead. To perform this method, optimum conditions for conducting a heat treatment when forming electrodes at both ends of an oxide superconductor current lead are detected. Thereby, the contact resistivity during a superconducting coil becomes extremely small. Further, the critical current density is considerably enhanced. In the case of this method, an oxide superconductor (8) obtained by finishing a final sintering process is first worked into or shaped like a rod or a pipe.

Abstract: A process for producing a fcc metal consisting of copper having random orientations comprising cross rolling which is performed to achieve a total draft of at least 20% with the rolling axis being offset at 15° or more in each pass to a total offset of at least 90°, and subsequent full annealing which is accompanied by recrystallization, the fcc metal satisfying the following relationships: I(200)/I(111)≦2.3 and I(220)/I(111)≦1.0, where I(111), I(200) and I(220) are the integral intensities of the (111), (200) and (220) faces, respectively, of crystal faces as measured by X-ray diffractiometry.

Abstract: An electronic circuit substrate including an aluminum-ceramic composite material having an electronic circuit formed on aluminum or an aluminum alloy plate of the aluminum-ceramic composite material which is prepared directly solidifying molten aluminum or an aluminum alloy on at least a portion of a ceramic substrate.

Abstract: The invention provides a process for producing a coated Cu alloy having a surface which has a low coefficient of friction and a high resistance to abrasion and is suitable for fabricating connectors, charging-sockets of electric automobiles etc. The coated Cu alloy is produced by coating the surface of a copper alloy with Sn and heat treating the coated Cu alloy at a temperature in the range of 100-450° C. for 0.5-24 hours. The Cu alloy which is coated with Sn consists of 1-41 wt % Zn with the balance being Cu and incidental impurities. By using the coated Cu alloy, the force of insertion, resistance to abrasion and resistance to corrosion of connectors can be significantly improved.

Abstract: An oxide superconductor which exhibits an uniform and high critical current is disclosed. Further, a method of manufacturing this oxide superconductor is disclosed, namely, a RE—Ba—Cu—O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than a melting point of a raw material mixture containing a RE-compound raw material, Ba-compound raw material and a Cu-compound raw material, on the raw material mixture. This method further includes a step of crushing the raw material mixture into particles and establishing the mean particle diameter of one or all of the raw materials as ranging from 50 to 80 &mgr;m.

Abstract: Iron oxyhydroxide particles that are composed of acicular particles having an average major axis of 0.01 to 0.5 &mgr;m and containing not less than 0.1 wt. % and not more than 30 wt. % of Al in the iron oxyhydroxide and that release not less than 0.1 wt. % and not more than 2 wt. % of H2O at 100° C. are used as particles of a lower layer of a coating type magnetic recording medium having a multi-layer structure. The acicular particles include ones having two or more branches whose branching direction is skewed toward a two-dimensional orientation.