The Analytical centrifuge – an additional tool to optimize ceramic slurries for spray drying
- Spray drying is a widely used process step in ceramic technology to
convert fine grained raw powders to free-flowing granules. Type and
amount of the organic additives (dispersants, binders and plasticizers)
define viscosity and stability of the slurry, the granulate structure and
the compaction behaviour.
Alumina and Zirconia powders were characterized with regard to
particle size, shape and specific surface area (BET). Zeta-potential
measurements by Stabino® were used to investigate the effect of
different dispersants on slurry stability. Unfortunately, this method is
restricted to suspensions with less than about 30% by weight of solid
content. The multi-sample analytical centrifuge LUMiSizer® overcomes
this problem. This device enables analysis of the separation behaviour
of suspensions over a wide range of solid content. On the basis of
position and time resolved photometric detection of transmitted light,
it is possible to determine the instability index, theSpray drying is a widely used process step in ceramic technology to
convert fine grained raw powders to free-flowing granules. Type and
amount of the organic additives (dispersants, binders and plasticizers)
define viscosity and stability of the slurry, the granulate structure and
the compaction behaviour.
Alumina and Zirconia powders were characterized with regard to
particle size, shape and specific surface area (BET). Zeta-potential
measurements by Stabino® were used to investigate the effect of
different dispersants on slurry stability. Unfortunately, this method is
restricted to suspensions with less than about 30% by weight of solid
content. The multi-sample analytical centrifuge LUMiSizer® overcomes
this problem. This device enables analysis of the separation behaviour
of suspensions over a wide range of solid content. On the basis of
position and time resolved photometric detection of transmitted light,
it is possible to determine the instability index, the sedimentation
velocity, and the sediment height in dependence of type and amount
of organic additives at various centrifugal accelerations. Additional
information is obtained from the shape of the transmission profiles.
Based on LUMiSizer® measurements, suitable additive concentrations
were derived. Thereby, the number of investigations by viscometry and
spray drying experiments can be significantly reduced.
Finally, it was possible to produce alumina, zirconia and ZTA aqueous
slurries with up to 80 weight-% of solid. The optimized suspensions
were successfully spray dried and the resulted granules show good
compaction behaviour.…
MetadatenAutor*innen: | Petra Kuchenbecker |
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Koautor*innen: | Wolfgang Güther, Franziska Lindemann, Patrick Höhne, Christian Neumann, Torsten Rabe |
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Dokumenttyp: | Vortrag |
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Veröffentlichungsform: | Präsentation |
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Sprache: | Englisch |
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Jahr der Erstveröffentlichung: | 2016 |
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DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
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Freie Schlagwörter: | Analytical centrifuge; Ceramic suspension; Granules; Slurry; Spray drying |
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Veranstaltung: | Jahrestagung der Deutschen Keramischen Gesellschaft und Symposium Hochleistungskeramik |
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Veranstaltungsort: | Freiberg, Germany |
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Beginndatum der Veranstaltung: | 07.03.2016 |
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Enddatum der Veranstaltung: | 09.03.2016 |
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Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
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Datum der Freischaltung: | 20.05.2016 |
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Referierte Publikation: | Nein |
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Eingeladener Vortrag: | Nein |
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