Abstract: A filter assembly for use in an air remediation system is provided. The filter assembly includes a first and second filter member, each of which has a plurality of openings to define a plurality of separate flow passages. A granular filter material layer is disposed between the first and second filter members. A frame structure containing each of the first and second filter members as well as the granular filter material forms the self contained filter assembly.

Abstract: A high temperature mold assembly particularly adapted for thermit reaction welding, and mold components and mold compositions therefor, based on a mined aggregate containing carbon and silica and thermosetting, non-hygroscopic resinous binder.

Abstract: A plug for closing the opening in the bottom of a top pouring ingot mold is comprised of a preformed plug body having top and bottom ends and an outer peripheral surface providing a contour generally corresponding with that of the mold opening to be plugged. The lower portion of the outer peripheral surface is provided with a coating of a thermally curable sealing composition having a heavy paste-like consistency, and the plug body and coating are enclosed in a heat shrinkable plastic film. In use, the plug is pushed into a plug opening in the bottom of an ingot mold which generally is hot from a previous casting operation, the plastic film disintegrates, the sealing material is squeezed so as to spread and fill the space between the mold opening and plug body, and the heat of the mold cures the sealing material to secure the plug in place and seal the peripheral space between the plug body and mold opening.

Abstract: A process for the manufacture of silicon carbide crystals and whiskers comprises reacting at a temperature between 1,400.degree. C. and 2,100.degree. C. and in the presence of an inert gas, a material including as essential ingredients carbon, alumina, iron oxide, potassium oxide, and silica in an amount to provide a carbon to silicon ratio of from about 0.84:1 to about 2.17:1.