Decomposition of Li2CO3 by Interaction with SiO2 in Mold Flux of Steel Continuous Casting

The effect of SiO2 addition on the decomposition of Li2CO3 was investigated using the thermo-gravimetric and differential scanning calorimetric method (TG-DSC) at temperatures up to 1000°C. Addition of SiO2 greatly enhanced the decomposition of Li2CO3. The main decomposition reaction began to take p...

Full description

Saved in:
Bibliographic Details
Published in:ISIJ International 2004/02/15, Vol.44(2), pp.334-341
Main Authors: Kim, Jong-Wan, Lee, Yong-Deuk, Lee, Hae-Geon
Format: Article
Language:English
Subjects:
activation energy
Applied sciences
decomposition
Exact sciences and technology
Gravity die casting and continuous casting
Iron and steel making
Li2CO3
Metallurgical fundamentals
Metals. Metallurgy
mold flux
Production of metals
SiO2
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The effect of SiO2 addition on the decomposition of Li2CO3 was investigated using the thermo-gravimetric and differential scanning calorimetric method (TG-DSC) at temperatures up to 1000°C. Addition of SiO2 greatly enhanced the decomposition of Li2CO3. The main decomposition reaction began to take place around 600°C, and completed just above the melting point of Li2CO3. The decomposition product was Li2O · SiO2 irrespective of the Li2CO3 to SiO2 mixing ratio as long as both reactants were available. It was ascertained that a liquid layer between Li2CO3 and SiO2 particles formed and facilitated the decomposition reaction. The governing reaction of the decomposition was the reaction between the dissolved Li2CO3 and SiO2 in the liquid layer to form Li2O · SiO2. The decomposition rate was independent of the Li2CO3/SiO2 mixing ratio until either one had been completely exhausted. When excess Li2CO3 existed, it further reacted with the initial product of Li2O · SiO2 to form 2Li2O · SiO2. When SiO2 was found in excess, on the other hand, no further reaction took place. This is attributed to the fact that upon Li2CO3 exhaustion there is no liquid phase available to facilitate further reaction. The apparent activation energy of the decomposition of Li2CO3 in existence with SiO2 is 198 kJ mol−1.
ISSN:0915-1559
1347-5460
DOI:10.2355/isijinternational.44.334