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.…
Autor*innen: | Petra Kuchenbecker |
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Koautor*innen: | Wolfgang Güther, Franziska Lindemann, Patrick Höhne, Christian Neumann, Torsten Rabe |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2016 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | Analytical centrifuge; Ceramic suspension; Granules; Slurry; Spray drying |
Veranstaltung: | Jahrestagung der Deutschen Keramischen Gesellschaft und Symposium Hochleistungskeramik |
Veranstaltungsort: | Freiberg, Germany |
Beginndatum der Veranstaltung: | 07.03.2016 |
Enddatum der Veranstaltung: | 09.03.2016 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 20.05.2016 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |