Premium
On the Reactions Occurring in the CaOCr 2 O 3 O 2 system
Author(s) -
Solymosi F.,
Nagy IréN
Publication year - 1970
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.19703780212
Subject(s) - spinel , chromite , chromate conversion coating , oxygen , partial pressure , chromium , inorganic chemistry , oxygen pressure , chemistry , atmosphere (unit) , oxide , mineralogy , materials science , metallurgy , thermodynamics , physics , organic chemistry
Abstract The reactions occurring in the system CaOCr 2 O 3 O 2 have been investigated. In the mixture of two oxides heated in air to higher temperature calcium chromate and chromite are being formed. The rate and the ratio of the two reactions is very sensitive to the composition of gaseous atmosphere, especially to the partial pressure of oxygen. The formation of spinel was accelerated by a small amount of oxygen but was partly or fully suppressed at a higher oxygen pressure on the expense of chromate formation. The oxidation of CaOCr 2 O 3 was also studied kinetically. Detailed measurements in different gaseous atmospheres were performed with doped CaO and Cr 2 O 3 . The results were interpreted in the light of the defect structure of the reacting oxides.