Studies on the interactions of metal oxides and Na2 SO4 at 1100 and 1200 K in oxygen |
| |
Authors: | M Mobin A U Malik Sultan Ahmad S K Hasan M Ajmal |
| |
Affiliation: | (1) Department of Applied Chemistry, Z. H. College of Engineering and Technology, Aligarh Muslim University, 202 002 Aligarh, India;(2) Corrosion Research Centre, SWCC, Al-Jubail, KSA |
| |
Abstract: | The interaction of different metal oxides such as Co3O4, NiO, Al2O3, Cr2O3, Fe2O3 and SiO2 with Na2SO4 at a temperature of 1100 and 1200 K in flowing oxygen has been studied. The thermogravimetric studies for each system were
carried out as a function of Na2SO4 in the mixture. The presence of different constituents in the reaction products were identified by X-ray diffraction analysis
and the morphologies of the reaction products were characterized using metallography and scanning electron microscopy (SEM).
The formation of products was also investigated by thermodynamic computation of free energies of the reactions and the study
of relevant equilibrium phase diagrams. The soluble species in the aqueous solutions of the reaction products were determined
quantitatively using atomic absorption spectrophotometry.
The high temperature interaction products usually contain a 3-phase structure namely, Na2O·M2O
x
, M2O
x
and metal sulphide and/or metal sulphate. The formation of Na2O·M2O
x
depends upon the solid state solubility of metal oxide in the molten salt at high temperatures. Under limited solubility
conditions Na2O·M2O
x
is invariably formed, but as soon as this condition is relaxed the oxide. M2O
x
, precipitates and forms a separate phase. |
| |
Keywords: | High temperature interactions metal oxide solubility thermogravimetric analysis morphologies of the reaction products |
本文献已被 SpringerLink 等数据库收录! |
|