Title: A new method of potassium chromate production from chromite and KOH-KNO3-H2O binary submolten salt system
Authors: Sun, Zhi
Zhang, Yi ×
Zheng, Shili
Zhang, Yang #
Issue Date: Oct-2009
Publisher: American Institute of Chemical Engineers
Series Title: AIChE Journal vol:55 issue:10 pages:2646-2656
Abstract: A new method of chromate production by applying a new reaction system of KOH-KNO3-H2O (binary submolten salt system) is proposed and proved feasible. Under conditions of temperature 350°C, KOH-to-chromite ore ratio 2:1, stirring speed 700 rpm, KNO3-to-chromite ore ratio 0.8:1, oxygen partial pressure 50%, and gas flow 1 L/min, chromium conversion ratio obtained is >98% with reaction time around 300 min. The decomposition of chromite ore in the system is a typical process of solid- liquid-gas reaction, which is coordinately controlled by mass diffusion in product layer and interface reaction. Apparent activation energy of decomposition in the temperature range from 280 to 370°C is 55.63 kJ/mol. During reaction, oxygen dissolves into KOH-KNO3-H2O melt system first and some cluster, e.g. O, is formed and the mass diffusion coefficient of the cluster was calculated. The system can be considered as both a media of oxygen transportation and reactant donator. Potassium nitrate plays a role of catalyst in the oxidation decomposition reaction of chromite ore and potassium hydroxide
ISSN: 0001-1541
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Chemical and Extractive Metallurgy Section (-)
× corresponding author
# (joint) last author

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