Resumo

HASAN, S.K.  e  MOBIN, M.. High Temperature Interaction of NiO with Sodium Sulphate in SO₂ Environment at 1100 and 1200 K. Port. Electrochim. Acta [online]. 2011, vol.29, n.3, pp.187-196. ISSN 0872-1904.

The present paper contains the results relative to the reaction of NiO with Na₂SO₄ in presence of SO₂ (g) at 1100 and 1200 K. Nickel oxide (NiO) is produced by the oxidation of metal alloys in many industrial operations. The oxidation of metal and metal oxides in presence of molten salts and gas environment at high temperature is often called as hot corrosion. In this investigation the studies have been carried out taking into consideration the influence of SO₂ partial pressure. The thermo-gravimetric studies have been carried out as a function of Na₂SO₄ concentration in the mixture. The reaction products identified by XRD analysis and surface morphologies of the products were discussed on the basis of metallographic and scanning electron microscopic (SEM) studies. The pH of the aqueous solutions of the reaction products were measured to observe the changes in the system with varying the Na₂SO₄ concentration. A quantitative estimation of soluble metal ions has also been carried out with the help of an atomic absorption spectrophotometer. The possibility of chemical reaction is established by thermodynamic calculations of free energies of the reaction products.

Palavras-chave : high temperature; hot corrosion; metal oxide; sodium sulfate; XRD; SEM; NiO.

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