| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing heavy nitrogen which stably concentrates heavy nitrogenN by lessening an amount of a SOgas dissolved into HSOby-produced in a reflux column and by stably feeding an HNOaqueous solution.SOLUTION: In a method for concentrating and manufacturing heavy nitrogen using an apparatus for concentrating and manufacturing heavy nitrogen equipped with a reflux column 20, 200 which form nitrogen monoxide gas by a gas-liquid contact reaction of a nitric acid solution and a sulfur dioxide gas, and an exchange column 10, 100 which condense the heavy nitrogen to nitric acid by a nitrogen isotope chemical exchange of the nitrogen monoxide gas and the nitric acid solution formed in the reflux column, a temperature of the nitric acid solution fed to the exchange column 10, 100 is controlled at 10-15°C, a temperature of the sulfur dioxide gas fed to the reflux column 20, 200 is controlled at 35-40°C, and a temperature of nitric acid formed together with the nitrogen monoxide gas in the gas-liquid contact reaction of the nitric acid solution and the sulfur dioxide gas in the reflux column 20, 200 is controlled at 65-75°C. |
