Abstract: A high purity silver wire for use in recording, acoustic or image transmission applications. The high purity silver wire is made of high purity silver containing sulfur, iron, copper, palladium, gold and lead impurities in an amount such that no one of the sulfur, iron, copper, palladium, gold and lead impurities individually exceeds 0.5 ppmw, and wherein all other impurities are present in a total amount of less than 1 ppmw.

Abstract: In a process for separating impurities from a raw gallium material containing impurities, a process for refining gallium comprising progressively solidifying a raw gallium material provided in a liquid state inside a vessel while applying stirring, such that the diameter of the tubular solidification boundary gradually advances from the inner wall plane of the vessel towards the center of the vessel to reduce the diameter of the tubular solidification boundary, and separating the liquid phase remaining in the central portion of the vessel from the solidified phase before the entire raw material inside the vessel is solidified. The process above is repeated as required by using, as the raw gallium material, the solidified phase from which the liquid phase is separated. A metallic gallium favorably used for the preparation of a compound semiconductor can be obtained by analyzing the impurity concentration of the impurity-concentrated Ga separated from the solidified layer.

Abstract: In a process for separating impurities from a raw gallium material containing impurities, a process for refining gallium comprising progressively solidifying a raw gallium material provided in a liquid state inside a vessel while applying stirring, such that the diameter of the tubular solidification boundary gradually advances from the inner wall plane of the vessel towards the center of the vessel to reduce the diameter of the tubular solidification boundary, and separating the liquid phase remaining in the central portion of the vessel from the solidified phase before the entire raw material inside the vessel is solidified. The process above is repeated as required by using, as the raw gallium material, the solidified phase from which the liquid phase is separated. A metallic gallium favorably used for the preparation of a compound semiconductor can be obtained by analyzing the impurity concentration of the impurity-concentrated Ga separated from the solidified layer.

Abstract: An apparatus for producing a high-purity silver material. The apparatus includes an electric furnace. The electric furnace has an outer cylinder which encloses an inner cylinder. The outer cylinder is capable of being evacuated with a vacuum pump. A recovery mold is disposed within the inner cylinder. An aspiration table is connected to a central portion of the recovery mold. A feed crucible is disposed above the recovery mold and is connected to the aspiration table. A cooling trap is disposed below the recovery mold. A water-cooling flange is disposed below the cooling mold.

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: 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.