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Preparation and Kinetic Considerations for the Dissolution of Cr‐substituted Iron Oxides in Reductive‐complexing Formulations
Author(s) -
Manjanna Jayappa,
Venkateswaran Gopala
Publication year - 2002
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450800511
Subject(s) - dissolution , hematite , chemistry , magnetite , oxide , kinetic energy , citric acid , kinetics , mass fraction , inorganic chemistry , particle size , ascorbic acid , iron oxide , materials science , mineralogy , metallurgy , organic chemistry , physics , food science , quantum mechanics
The dissolution rate coefficients of Cr‐substituted (0‐20 at.% Cr) iron oxides viz. hematite and magnetite were determined by using an inverse cubic rate (ICR) law applicable for spherical particles as well as by a general kinetic equation (GKE) applicable for polydispersed particles. An attempt is made to compare both the treatments for different kinds of dissolution profiles obtained by employing oxides with narrow particle size distribution in V(II)‐EDTA and citric acid‐EDTA‐ascorbic acid formulations at 353±5K. The dissolution profiles could be classified into three types based on the nature of oxide and formulations. It is observed that both ICR and GKE treat the dissolution course as a function of decrease in fraction of undissolved mass, m/m 0 . The dissolution rate coefficients determined by ICR and GKE have shown the similar trend of decrease with increasing Cr content of the oxides and was ascribed to lattice stabilization.