Abstract: Disclosed herein are a process for producing a carbonaceous thin plate comprisingdisposing a composite material comprising a carbonaceous raw material which is carbonized and solidifies after being softened by heating and paper-like substances which are carbonized without melting between the pressing-surfaces of a heating press, so as to sandwich said carbonaceous raw material between said paper-like substances and to contact said paper-like substances with each of the pressing-surfaces of said heating press,press-molding said composite material by raising a temperature of said heating presscontinuously heating the thus press-molded composite material under a pressure, thereby carbonizing the thus press-molded composite material, andcalcining the thus carbonized material under a reduced-pressure or in an inert gas.

Abstract: A catalyst having high activity at a low temperature is obtained by heating rhodochrosite in air at a temperature of 300.degree.-500.degree. C. A catalyst having still higher activity at a low temperature is obtained by mixing rhodochrosite with a specific amount of a specific metal compound and heating the resultant mixture in air at a temperature of 300.degree.-500.degree. C.

Abstract: There is disclosed a method for removing nitrogen oxides from a nitrogen oxide-containing gas by contacting the gas with ammonia excited by ultraviolet irradiation in the presence of a catalyst to react the nitrogen oxides with the ammonia. According to the method, the reaction of nitrogen oxides with ammonia proceeds more rapidly than in the case of prior art methods.

Abstract: Spheres of activated carbon are obtained by adding to 100 parts by weight of pitch 10 to 50 parts by weight of an aromatic solvent compatible with said pitch and 2 to 50% by weight, based on the total weight of said pitch and said aromatic solvent, of a nitrogen-containing compound, melting and mixing them with one another, molding the resultant mixture in the form of spheres, removing the aromatic solvent by means of solvent extraction to convert said spheres into porous pitch spheres containing 2 to 60% by weight of nitrogen, infusibilizing the resultant micro-porous pitch spheres and thereafter activating the infusibilized pitch spheres.