Abstract: Molded, or pressed articles on pyrogenically produced zirconium dioxide are disclosed and having the following features:______________________________________ outside diameter 2-15 mm BET surface area per DIN 66 131 30-50 m.sup.2 /g total pore volume 0.3-0.8 ml/g pore size distribution no pores < 10 nm, at least 80% of the pores in the range of 10-70 nm diameter crushing strength 40-300 N composition at least 98% ZrO.sub.2, SiO.sub.2, remainder Al.sub.2 O.sub.3, and/or HfO.sub.2. ______________________________________These molded articles are manufactured by homogenizing pyrogenically produced zirconium dioxide with any one of kaolin, sugar, or urea, or mixtures while water is being added, by drying the mixture at a temperature of 80.degree. to 120.degree. C. and then comminuting it into a friable powder which then is pressed into molded articles which thereupon are annealed for 1 to 4 h at 600.degree. to 1,000.degree. C. The pressed articles are used as catalysts or as catalyst-carriers.

Abstract: The utilization of ethoxylated polyethyleneamines for addition to aqueous dispersions of pyrogenically prepared silicon dioxide in order to obtain an increase of the thickening action thereof.

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: 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 %.