Auftreten von Oszillationen bei der Denitrierung von salpetersauren, schwerund edelmetallhaltigen Lösungen

The effect of active carbon on the reduction of concentrated nitric acid by HCOOH

“…It can be seen that at 50 • C the reaction products started to be observed after an induction period as long as 120 min, whereas at 100 • C the generation of reaction products started shortly (lesser than 30 min) after the reactants were come into contact. For same reactants concentrations, Guenais-Langlois et al [4] found 17 min of induction period at 70 • C. In fact the increase in the induction time with decreasing temperature can be approximated by Arrhenius law [8]. Regardless of the reaction temperature, one of the common features of HCOOH-HNO 3 reaction is that the formation of HNO 2 is observed just before the release of gaseous (final) products (CO 2 and NO x ).…”