| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for recovering ammonium nitrate as a highly concentrated aqueous ammonium nitrate solution or ammonium nitrate which is solid at normal temperature, from waste water containing nitric acid, ammonia or ammonium nitrate in low concentration generated in an industrial field. SOLUTION: The method for recovering the ammonium nitrate from the waste water includes: neutralizing the waste water containing a nitrogen-containing component selected from nitric acid, ammonia or ammonium nitrate in low concentration with ammonia or nitric acid if necessary; concentrating the waste water to prepare an aqueous ammonium nitrate solution having concentration of 40-65 wt.% ("intermediate-concentration ammonium nitrate solution"); adjusting the pH of the intermediate-concentration ammonium nitrate solution to a range of 5-8 by adding nitric acid or ammonia to the solution when the pH of the solution is not within a range of 5-8; and preparing an aqueous ammonium nitrate solution having concentration of 70-90 wt.% ("high-concentration ammonium nitrate solution") by carrying out further concentration. COPYRIGHT: (C)2010,JPO&INPIT |
