Abstract: Pressed objects (slugs) of pyrogenically produced oxides such as SiO.sub.2, Al.sub.2 O.sub.3 and TiO.sub.2 are produced using a silica sol and water. As molding assistants thereby there is employed a polyhydric alcohol, e.g. glycerine or sorbitol. The water can be added adsorbed on a pyrogenically produced hydrophobized silica. The pressed object obtained can be used inter alia as catalyst carrier.

Abstract: Powders with a relatively low bulk density can be emptied from transportation containers only with a large and undesired production of dust. The apparatus for emptying powder-filled containers consists of a suction tube on which a fluidizing device is arranged in the neighborhood of the open end of the tube. This fluidizing device can have the form of a double-jacketed cone concentrically about the tube, or a hollow sphere concentrically about the tube. Fluidizing air can be introduced into the powder through bores arranged in the direction of the opening of the tube. To prevent the suction tube being sucked onto the container wall, the opening of the suction tube has a crenelated edge.

Abstract: There is produced a hydrophobic mixture for RTV and LTV silicone rubber by applying a hydrophobizing agent to a precipitated silica, homogeneously mixing this powdery concentrate into a pyrogenically produced silica, tempering the mixture and mechanically compacting. The hydrophobic filler mixture obtained in the untempered condition consists of:Pyrogenically produced silica: 50 to 85 weight %Precipitated silica: 5 to 40 weight % (e.g. 5 to 30 weight %)Hydrophobization agent: 8 to 30 weight %Aluminum oxide: 0.5 to 5 weight %.