Abstract: A scavenger for injecting gas into molten material where a refractory member fits within an opening in a refractory lining. The cold face of the scavenger fits within a recess of a base that includes a gas conduit in the form of a double spiral. The gas conduit in the base is in flow communication with the gas transmitting means in the gas scavenger.

Abstract: Refractory chrome-magnesia bricks and compositions composed of a granular fused material having a grain size of 12 mm or less, and a content of from 71 to 83 wt. % Cr.sub.2 O.sub.3 and from 17 to 29 wt. % MgO, the minimum content of Cr.sub.2 O.sub.3 and MgO being 94 wt. %.

Abstract: An improved process of forming sintered magnesia bodies from a magnesium hydroxide aqueous slurry wherein the slurry is dried to a moisture content where the solids can be compacted to self-supporting bodies, preferably about 5 to 8% moisture, by heating at a temperature below the dissociation temperature of the magnesium hydroxide, compacting the dried magnesium hydroxide into briquettes, heating the briquettes at a temperature above the dissociation temperature of magnesium hydroxide to form magnesia, re-compacting to form new briquettes of greater density, and heating to sintering temperature to sinter the briquettes.

Abstract: Method for the production of cement-bonded molded articles, particularly lightweight boards of wood fiber, wood chips or other lignocelluloses, of mineral fibers, glass fibers, plastic chips and fibers or various lightweight materials, like expanded silicates, expanded clay or expanded glass or granules of foamed plastics as a base material and portland cement as a binder, characterized in that the molded articles are produced in a heated molding duct formed of endless moving belts, for example, steel belts, using a portland cement as a binder in the molding compound which contains 1 to 30% by weight, perferably 15 to 25% by weight, of a calcium-halogen aluminate of the composition 11CaO.7Al.sub.2 O.sub.3.CaX.sub. 2 wherein X is any halogen. The cement with added calcium-halogen aluminate has such a short setting time, which is further accelerated by heating during molding, that boards may be successfully made on a continuous basis using a belt-molding machine.

Abstract: A clamping device adapted to tighten a screen bottom onto a screen frame in a screening apparatus. The clamping device is provided with means disposed on one side of the screen frame for pneumatically tightening one side of the screen bottom to that side of the screen frame, the opposite side of the screen bottom being attached to the opposite side of the screen frame. The pneumatic tightening means is provided with a flexible inflatable hose and a compressed air source connected to the hose for inflating and deflating the hose.

Abstract: Burned magnesite bricks are impregnated with an aqueous dispersion of carbon black, and then dried using hot dry air at a temperature above about 100.degree.C.