Ferrous Oxidation Catalyzed by Oxy-Nitrogen Species (NOx)


GÖK Ö.

ASIAN JOURNAL OF CHEMISTRY, cilt.24, sa.12, ss.5485-5489, 2012 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 24 Sayı: 12
  • Basım Tarihi: 2012
  • Dergi Adı: ASIAN JOURNAL OF CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.5485-5489
  • Anahtar Kelimeler: Autocatalysis, COMSOL, Kinetics, Mathematical modeling, Oxy-nitrogen species, ACID, ABSORPTION, MECHANISM, KINETICS
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The effect of small concentrations of nitrite (4.5 mM) on 0.1 M ferrous sulfate oxidation in a 1 M sulfuric acid under 4 atm oxygen pressure at 25, 60 and 80 degrees C was investigated. A mathematical model for reaction was developed and COMSOL software was used to simulate the concentration versus time trajectories in parallel with previous thermodynamic and kinetics investigations on related systems. Tie simulations and experiments revealed that nitrous acid disproportionates to produce N2O3, NO and NO2 and subsequently, these oxy-nitrogen species are all oxidized to N(V). The oxidation rate of ferrous at higher temperatures with nitrite was 32 times faster compared to that with only oxygen present. The activation energy for ferrous oxidation was found to be 34.51 kJ mol(-1). It is expected to identify the key reaction pathways involved in leaching processes including NOx by avoiding much of the expensive Edisonian experimentation that slows innovation.