Abstract: A formwork apparatus for concrete placing comprises: a center frame assembly having upper and lower ends; first and second form panels for molding concrete walls, each having a supporting member mounted on an outer surface thereof, the first form panel pivotally connected at its supporting member to the upper end of the frame assembly so as to be pivoted about a substantially horizontal axis, the second form panel pivotally connected at its supporting member to the lower end of the frame assembly so as to be pivoted about an axis parallel to a pivot connecting the first panel with the frame assembly; a first fixing mechanism for fixing and releasing the first panel to and from a cured concrete wall; a second fixing mechanism for fixing and releasing the second panel to and from the concrete wall; a first drive mechanism for pivoting the frame assembly around the first panel when the first panel is fixed to the concrete wall so that the second panel is brought to a position upper side of the first panel; and a

Abstract: An aluminum oxynitride refractory of a sufficiently high nitrogen content is produced efficiently and inexpensively by a method which comprises mixing alumina of Bayer Process with aluminum dross and electrically fusing the resultant mixture in an electric furnace.