Abstract: This invention relates to a process for the manufacture of catalysts for the reduction of oxides of nitrogen from exhaust gases and in chemical air cleaning processes in which a catalytically active material containing iron ores, chromium ores and/or zeolite is placed in contact with a carrier means having a series of openings; e.g., wire mesh, expanded or perforated metal or any type of grid-like structure to form a catalytic member. The carrier means is etched with an acid etchant before forming the catalytic member or, instead, the catalytic member is etched with an acid etchant. The catalytic member is bonded by a thermal treatment; e.g., drying, tempering and/or fixing. This invention also relates to catalytic members or products produced by the process. This invention proposes the use of pressure bonding to obtain a catalytic member product which has significantly improved catalytic activity, greater mechanical strength and higher resistance to chipping.

Abstract: A process for the manufacture of catalysts for the reduction of nitrogen oxides in exhaust gases or for chemical air cleaning processes, in which catalyst moldings are produced from a mixture of solid primary materials which include iron oxide or mixtures of iron oxide and chromium oxide and/or manganese oxide, which are reduced to grain sizes less than 2 mm, with the use of inorganic binders and sulfuric acid, and with the possible addition of activating additives, wherein:(a) either the mixture of the solid primary materials is reacted with sulfuric acid, a mixture of sulfuric acid and phosphoric acid or mixtures of sulfuric acid and phosphoric acid containing sulfate, hydrogen sulfate, phosphate or hydrogen phosphate of ammonium, aluminum, iron, vanadium, manganese, molybdenum, chromium, copper and/or cobalt, and moldings are formed from this mixture, or the mixture of the solid primary materials is formed into moldings after the addition of fluid and/or phosphoric acid and/or phosphates, and these molding

Abstract: This invention relates to a process for the manufacture of catalysts for the reduction of nitrogen oxides in exhaust gases or for chemical air cleaning processes, in which catalyst moldings are produced from iron oxide or mixtures of iron oxide and chromium oxide and/or manganese oxide, which are reduced to grain sizes less than 2 mm, with the use of inorganic binders and sulfuric acid, and with the possible addition of activating additives.

Abstract: The invention relates to a catalyst in the form of a plate for nitrogen oxide reduction in exhaust gases manufactured by molding granular Cr.sub.2 O.sub.3 or a mixture of granular Fe.sub.2 O.sub.3 with Cr.sub.2 O.sub.3 with phosphoric acid or sulphuric acid as binder, characterized by the fact that a combination is molded of separately prepared mixtures of Cr.sub.2 O.sub.3 or (Fe.sub.2 O.sub.3 +Cr.sub.2 O.sub.3) with phosphoric acid as binder, and of Cr.sub.2 O.sub.3 or (Fe.sub.2 O.sub.3 +Cr.sub.2 O.sub.3) with sulphuric acid as binder.

Abstract: Exhaust gases containing residual nitric oxide constituents from a processing operation are maintained at an elevated pressure, heated to from 260.degree. C. to 340.degree. C. in a separate heat exchanger, and subjected to multi-stage catalytic reduction with ammonia to produce purified exhaust gases. The pressure of the thus purified exhaust gases is then relieved in an expansion turbine.

Abstract: Exhaust gases containing residual nitric oxide constituents from a processing operation are maintained at an elevated pressure, heated to from 260.degree. to 340.degree. C., and subjected to catalytic reduction with ammonia to produce purified exhaust gases. The pressure of the thus purified exhaust gases is then relieved in an expansion turbine.