Development of novel carbon bonded filter compositions for steel melt filtration

Influence of the Specimen Manufacturing Process on the Strength of Carbon‐Bonded Alumina (Al2O3–C)

“…The compostition is equal to the one described for the carbonbonded alumina filters by Emmel and Aneziris [1] and Storti et al [7] It consists of mainly 99.8% pure alumina (Martoxid MR 70, Martinswerk, Germany, d 90 3.0 mm). Additionally, there are three different carbon sources: modified coal tar pitch powder (Carbores 1 P, Ruẗgers, Germany, d 90 0.2 mm), fine natural graphite (AF 96/97, Graphit Kropfmuḧl, Germany, 96.7 wt% carbon, 99.8 wt% 40 mm), and carbon black powder (Luvomaxx N-911, Lehmann & Voss & Co., Germany, !…”

“…[1] In this case, the slurry is sprayed into little forms approaching final dimensions of the specimens. The final step after drying and coking is a surface finishing by grinding, in order to overcome the deviations of geometry and dimensions of the specimens resulting from drying shrinkage.…”

“…Usually, the filters are prepared in two steps [1] : First, polyurethane foams as templates are impregnated with the water based Al 2 O 3 -C slurry. After a drying step, they are spray coated with the same slurry, save a lower solid content, to the desired strut thickness.…”

“…Within the scope of the Collaborative Research Center CRC 920 open cell ceramic filters made of carbon-bonded alumina [1] are investigated. The manufacturing process is based on the replica technique by Schwartzwalder.…”

“…The manufacturing process of the carbon-bonded filters is described in detail by Emmel and Aneziris. [1] A temperature dependent characterization of the strength of the fine grained bulk material is required. This offers the possibility of a numerical simulation of a filter with any structure and answer whether the filter can withstand the loading during the filtration process.…”