Abstract: The present invention is to provide a process for producing a scorodite that can shorten the time required for synthesizing the scorodite, and further can improve the yield of arsenic and iron into the scorodite. Accordingly, a process for producing a crystalline scorodite from an acidic aqueous solution containing pentavalent As and trivalent Fe, wherein the synthesis of the crystalline scorodite is performed after the molar ratio of trivalent Fe to pentavalent As contained in the acidic aqueous solution is adjusted to be equal to or more than 0.9 and equal to or less than 1.1 is provided.

Abstract: The present invention provides a method for manufacturing scorodite in which scorodite may be obtained at high production efficiency and a high As concentration ratio. The present invention provides a method for manufacturing crystalline scorodite from acidic aqueous solution containing pentavalent As and trivalent Fe, the method comprising a step for adding a basic sodium compound to the acidic aqueous solution such that the sodium concentration in the acidic aqueous solution becomes larger than 0 g/L and equal to or less than 4 g/L.

Abstract: A method of making scorodite includes the following steps: (1) an acidic aqueous solution containing pentavalent As and trivalent Fe is heated at a temperature for a time, the temperature and the time being effective for synthesis of crystalline scorodite; (2) the synthesized scorodite is separated from the post-reaction solution by solid-liquid separation; and (3) the scorodite is washed with water and is separated from the washing solution by solid-liquid separation. Step (3) is repeated until the concentration of at least one component of the post-reaction solution contained in the washing solution used for washing the scorodite decreases to a predetermined level.

Abstract: The present invention is to provide a process for producing a scorodite that can shorten the time required for synthesizing the scorodite, and further can improve the yield of arsenic and iron into the scorodite. Accordingly, a process for producing a crystalline scorodite from an acidic aqueous solution containing pentavalent As and trivalent Fe, wherein the synthesis of the crystalline scorodite is performed after the molar ratio of trivalent Fe to pentavalent As contained in the acidic aqueous solution is adjusted to be equal to or more than 0.9 and equal to or less than 1.1 is provided.

Abstract: The present invention provides a method for manufacturing scorodite in which scorodite may be obtained at high production efficiency and a high As concentration ratio. The present invention provides a method for manufacturing crystalline scorodite from acidic aqueous solution containing pentavalent As and trivalent Fe, the method comprising a step for adding a basic sodium compound to the acidic aqueous solution such that the sodium concentration in the acidic aqueous solution becomes larger than 0 g/L and equal to or less than 4 g/L.

Abstract: A method of separating and processing a catalyst carrier that is contained in a processing object that includes a catalyst carrier metal cover to which an exhaust gas pipe is still connected, magnetic carrier foil or a ceramic carrier, a surface-enlarging coating film provided on the magnetic carrier foil or the ceramic carrier, and the catalyst carrier containing precious metal. This method includes the steps of: crushing the catalyst carrier and the metal cover to which the exhaust gas pipe is still connected, using a first crusher of a shearing type; breaking the catalyst carrier containing precious metal from the metal cover, using an impact-type pulverizer; and separating the catalyst carrier containing precious metals from the exhaust gas pipe and the metal cover, using a separator.

Abstract: A method of separating and processing a catalyst carrier that is contained in a processing object that includes a catalyst carrier metal cover to which an exhaust gas pipe is still connected, magnetic carrier foil or a ceramic carrier, a surface-enlarging coating film provided on the magnetic carrier foil or the ceramic carrier, and the catalyst carrier containing precious metal. This method includes the steps of: crushing the catalyst carrier and the metal cover to which the exhaust gas pipe is still connected, using a first crusher of a shearing type; breaking the catalyst carrier containing precious metal from the metal cover, using an impact-type pulverizer; and separating the catalyst carrier containing precious metals from the exhaust gas pipe and the metal cover, using a separator.

Abstract: A substrate wafer for epitaxy of a compound semiconductor single crystal and an epitaxy using the substrate wafer are disclosed. Where the orientation off-angle from the <100> plane of an area available for device formation of a surface of the substrate wafer is .theta..degree., and the growth rate on an epitaxial layer on the substrate wafer is V .mu.m/hr, and the growth temperature of the epitaxial layer is T K, the orientation off-angle .theta..degree. is given by the following expression: ##EQU1## where 0.1.ltoreq.V.ltoreq.10 and 853.ltoreq.T.ltoreq.1023. The substrate wafer is capable of significantly reducing the number of teardrop-like hillock defects which appear on the surface of the epitaxial layer and of increasing the smoothness of the surface of the epitaxial layer.

Abstract: A container for shipping and storing articles such as semi-conductor materials, comprises a first case member having a bottom wall, a second case member having an annular flange, and a supporting sheet having a thin flexible base film and an adhesive layer applied thereto. The adhesive layer is capable of tentatively adhering thereto an article to be packaged. The first and second case members is adapted to make with each other in a sealed manner and to cooperate to define an internal space therebetween when mated together. The supporting sheet is placed in said first case member with the adhesive layer facing toward the second case member and with the peripheral margin of the supporting sheet held between the bottom wall of the first case member and the annular flange of the second case member.