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Batch‐to‐Melt Conversion Kinetics in Sodium Aluminosilicate Batches Using Different Alumina Raw Materials
Author(s) -
Christmann Anja I.,
Deubener Joachim,
Hochrein Oliver,
Mondeshki Mihail
Publication year - 2016
Publication title -
international journal of applied glass science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 34
eISSN - 2041-1294
pISSN - 2041-1286
DOI - 10.1111/ijag.12183
Subject(s) - gibbsite , materials science , cristobalite , aluminosilicate , dissolution , boehmite , spinel , corundum , crystallization , analytical chemistry (journal) , crystal (programming language) , kinetics , mineralogy , chemical engineering , quartz , chemistry , aluminium , chromatography , metallurgy , catalysis , physics , quantum mechanics , computer science , engineering , programming language , biochemistry
The batch‐to‐melt conversion in batches of sand, soda ash and corundum (C), alumina spinel (A), boehmite (B), or gibbsite (G) as Al 2 O 3 carrier are studied using thermal analysis, X‐ray diffraction, and 27 Al nuclear magnetic resonance spectroscopy. Laboratory‐scaled batches are either heated continuously or quenched from 1600°C in a series of increasing dwell times. The results show that the conversion from the raw materials to the fresh melt proceeds in two kinetic stages. During the first stage (3–5 min), fast conversion of nearly 95% by mass occurs and the conversion coefficient increases in the order G < C ≈ A < B. The second stage is controlled by the slow dissolution of intermediate crystal phases, such as cristobalite, carnegieite, sodium metasilicate, and diaoyudaoite, which leads to an increase in the total batch‐to‐melt turnover time of up to 10 min. No direct correlation between the kinetic parameters characterizing the first stage and the fraction and dissolution speed of intermediate crystals of the second stage could be established.