Dowa Mining Co., Ltd.

Kishio Tayama

Takashi Ohgami

Hiroshi Miura

Shunichi Kimura

Toshiaki Hodozuka

Hidekazu Kato

Nagayasu Yanata

Kenichi Tayama

Takeharu Yamamura

Kanichi Okuda

A 99.99% pure indium feed is charged into a crucible and heated to 1250 &#xb0; C. by an upper heater in a vacuum atmosphere at 1&#xd7;10Torr, whereupon indium evaporates, condenses on the inner surfaces of an inner tube and drips to be recovered into a liquid reservoir in the lower part of a tubular member, whereas impurity elements having a lower vapor pressure than indium stay within the crucible. The recovered indium mass in the liquid reservoir is heated to 1100&#xb0; C. by a lower heater and the resulting vapors of impurity elements having a higher vapor pressure than indium pass through diffuser plates in an upper part of the tubular member to be discharged from the system, whereas the indium vapor recondenses upon contact with the diffuser plates and returns to the liquid reservoir, yielding 99.9999% pure indium, while preventing the loss of indium.

Method and apparatus for enhanced purification of high-purity metals

A purification apparatus including a vertical stack of a feed heating zone having a feed crucible, a condensation zone having a plurality of condensation vapor passage plates, a solidification zone having a solidification crucibleand an entrapment/solidification zone having a plurality of entrapment/solidification vapor passage plates

Apparatus for metal purification

A process for metal purification comprising a first step for heating a feed metal in a feed crucible to generate a vapor of the metal, a second step for directing the vapor into a condensation passageway for vapors, where part of the vapor is condensed to generate a molten condensate, a third step for directing the vapor through the condensation passageway for vapors into a solidification crucible so that the vapor is cooled to solidify said metal in a high-purity form, and a fourth step for returning the molten condensate into the feed crucible.

Process for producing high-purity metals

A 99.99% pure indium feed is charged into crucible and heated to 1250&deg; C. by upper heater in a vacuum atmosphere at 1&times;10 Torr, whereupon indium evaporates, condenses on the inner surfaces of inner tube and drips to be recovered into liquid reservoir in the lower part of tubular member whereas impurity elements having lower vapor pressure than indium stay within crucible . The recovered indium mass in liquid reservoir is heated to 1100&deg; C. by lower heater and the resulting vapors of impurity elements having higher vapor pressure than indium pass through diffuser plates in the upper part of tubular member to be discharged from the system whereas the indium vapor recondenses upon contact with diffuser plates and returns to liquid reservoir , yielding 99.9999% pure indium while preventing the loss of indium.

Apparatus for enhanced purification of high-purity metals

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.

High-purity silver wires for use in recording, acoustic or image transmission applications

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.

High purity gallium for preparation of compound semiconductor, and method and apparatus for purifying the same

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.

Apparatus for producing high-purity silver materials

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&deg; 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.

Process for producing high-purity silver materials

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.

Growing community of inventors

Akita, Japan

Kishio Tayama