Concentrated nitric acid, chlorine and nitrates from - nitrogen peroxide, oxygen, water and chlorides in

摘要

Conc. HNO3 is produced by reacting "nitrogen peroxide" (I), water and (gas contg.) O2 in presence of aqs. HNO3 soln. contg. (I) and nitrate(s) of group Ia metal with at wt. at least as high as that of K, which shifts azeotropic point upwards for HNO3, 70-100% HNO3 can thus be obtained directly from I, O2 and H2O at much lower temp. and pressure than usual. Reaction is carried out between room temp. and b.pt. pref. 30-70 degrees C and 1-100, pref. 1-10 atm., using alkali nitrate concn. is not >1/2 satn. value and 5-30% I. Conc. acid produced can be reacted with KCl, NaCl, HCl or NOCl, hence used in complete oxidation of HCl to Cl2 using air as oxidant, oxidation of NOCl to Cl2 and NO2 and prodn. of separate nitrates from mixed NaCl-KCl. Process is simple and expensive corrosion-proof equipment can be eliminated in some stages. (I) consists of NO2 and/or N2O4 and can also contain NO and N2O3.