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Peptization Control of Composite Materials Containing Water Glass for Spray Drying of Catalysts
Author(s) -
Saavedra Andres Carrasco,
Seifert Markus,
Hannß Mariella,
Henle Thomas,
Lê-Anh Mai,
Busse Oliver,
Weigand Jan J.
Publication year - 2021
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.202000480
Subject(s) - peptization , slurry , zeta potential , rheology , chemical engineering , shear thinning , materials science , mixing (physics) , spray drying , composite number , chemistry , composite material , chromatography , physics , quantum mechanics , nanoparticle , engineering
Silica‐based composite particles are complex catalyst materials that are widely used in petrochemistry. The preparation of particles that are well defined in form, composition, and chemical and rheological behavior by spray drying of suspensions remains an important industrial challenge. Here, zeolite HY, kaolin, and the cheap binder water glass are used. Experimental and model regimes of slurry peptization are analyzed based on their pH value, zeta potential, and mixing speed to control the process. The results show a pseudoplastic behavior of the silica slurries for zeta potential below 20 mV, which is explained by surface charge, hydroxyls, and pH‐dependent coagulation. Thus, a quick acidification of the slurry, additional mechanic shear, and subsequent pH control during spray drying enable control of peptization kinetics.