Abstract: The invention concerns the use of a composition based on TiO2 as a catalyst for hydrolyzing COS and/or HCN in a gas mixture, said composition comprising at least 1% by weight of at least one sulphate of an alkaline-earth metal selected from calcium, barium, strontium and magnesium.

Abstract: The invention relates to a process for direct oxidation into sulfur and/or into sulfate of sulfur-containing compounds that are contained in an amount that is less than 10% by volume in a gas, in which said gas is brought into contact with an oxidation catalyst that comprises a substrate and an active phase that comprises iron in a proportion of between 2 and 5% by weight of the oxidation catalyst at a temperature of less than 200° C. and in the presence of oxygen.

Abstract: The invention relates to a process for direct oxidation into sulfur and/or into sulfate of sulfur-containing compounds that are contained in an amount that is less than 10% by volume in a gas, in which said gas is brought into contact with an oxidation catalyst that comprises a substrate and an active phase that comprises iron in a proportion of between 2 and 5% by weight of the oxidation catalyst at a temperature of less than 200° C. and in the presence of oxygen.

Abstract: The invention concerns the use of a composition based on TiO2 as a catalyst for hydrolyzing COS and/or HCN in a gas mixture; said composition comprising at least 1% by weight of at least one sulphate of an alkaline-earth metal selected from calcium, barium, strontium and magnesium.

Abstract: A process is described for eliminating sulphur from a feed containing hydrogen sulphide, sulphur dioxide, carbon oxysulphide and/or carbon sulphide and a minimal quantity of benzene, toluene and/or xylenes in at least one reaction zone containing a catalyst, and recovering elemental sulphur and an effluent that is at least partially free of sulphur, the process being characterized in that the catalyst used is at least one catalyst containing a support comprising at least one compound selected from de group formed by alumina, titanium oxide and zirconia, the support further comprising at least one doping element selected from the group formed by iron, cobalt, nickel, copper and vanadium.

Abstract: Dry, freely-flowing, water-insoluble but readily dispersible, solid and homogeneous silica pigment particulates essentially spheroidal in geometrical configuration and having a mean particle size in excess of 80.mu., preferably in excess of 150.mu., are prepared by atomizing to dryness a pulverulent aqueous suspension of silica having a solids contact in excess of 18%. Such silica pigment particulates, advantageously comprised of precipitated silica, are well adapted as reinforcing fillers for elastomeric matrices.

Abstract: The invention concerns catalytic substances for the oxidation of ammonia, for the production of nitric acid, comprising cobalt oxide as the main component. Such substances, besides cobalt oxide, also contain additives formed of aluminum oxide and possibly oxides of thorium, cerium, zinc and cadmium, the amount of aluminum oxide added being from 5% to 15% by weight of the finished substances and the amount of the other oxides being from 0 to 25% by weight of the finished substances; these substances are in particular shaped by pelleting or extrusion, dried and then calcined at temperatures of the order of from 900.degree. to 1000.degree. C. The advantages of these catalytic substances lie in a high degree of activity and a high level of strength, which are maintained during use thereof.

Abstract: The invention concerns catalytic substances for the oxidation of ammonia, for the production of nitric acid, comprising cobalt oxide as the main component. Such substances, besides cobalt oxide, also contain additives formed of aluminum oxide and possibly oxides of thorium, cerium, zinc and cadmium, the amount of aluminum oxide added being from 5% to 15% by weight of the finished substances and the amount of the other oxides being from 0 to 25% by weight of the finished substances; these substances are in particular shaped by pelleting or extrusion, dried and then calcined at temperatures of the order of from 900.degree. to 1000.degree.C. The advantages of these catalytic substances lie in a high degree of activity and a high level of strength, which are maintained during use thereof.