| 摘要 |
1342577 Cobalt odide; nitric acid from NH 3 IMPERIAL CHEMICAL INDUSTRIES Ltd 14 Sept 1971 [1 Oct 1970 29 July 1971] 46775/70 and 35748/71 Heading C1A A catalyst, suitable for NH 3 oxidation, comprises cobalt oxide having a surface area in the range 0À1-7 m.<SP>2</SP>/g. and a volume/weight porosity in the range 1-15%. The catalyst may be in the form of cylinders having a size of 2-8 mm. and a mean vertical crushing strength of 35-1050 kg./cm.<SP>2</SP>. The catalyst may be prepared by (a) partly decomposing a cobalt carbonate, hydroxide or oxalate, to give a mixture containing the oxide and 13-25% of material volatile at 750‹ C. (e.g. CO 2 and H 2 O), (b) forming the mixture into particles, (c) completing the decomposition by heating to a temp. of 350-600‹ C. and then (d) sintering at 700-900‹ C. The catalyst is preferably operated at a temp. of 650-800‹ C. and in a bed depth of 8-30 particles in the oxidation of NH 3 to oxides of nitrogen. |
