Abstract
ZnAl2O4 has recently been reported to enhance thermomechanical properties and slag corrosion resistance of refractory castables. The pore generation and deleterious expansion during in situ ZnAl2O4 formation can limit their amount in a refractory composition. A comprehensive dilatometric study is presented, identifying the optimum raw materials and processing conditions. Preformed ZnAl2O4 refractory aggregates were synthesized from industrial ZnO and reactive Al2O3 by two-stage firing at 1050 ℃ and 1700 ℃ resulting in 0% open porosity. The ZnAl2O4 powder calcined at 1050 ℃ is also a good refractory matrix material as it has better sinterability than preformed refractory-grade MgAl2O4 and calcined alumina. The thermal expansion coefficient of ZnAl2O4 aggregate in the range of 70–1600 ℃ was found to be 10.7 × 10−6 K−1, which is similar to tabular Al2O3 (10.3 × 10−6 K−1) and MgAl2O4 (10.3 × 10−6 K−1), but lower than dead burned MgO (16.4 × 10−6 K−1), creating the possibility of developing thermal shock resistant refractories by utilizing this mismatch.
Original language | English |
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Pages (from-to) | 6244-6254 |
Number of pages | 11 |
Journal | Journal of the European Ceramic Society |
Volume | 42 |
Issue number | 13 |
DOIs | |
State | Published - Oct 2022 |
Funding
The US Department of Energy (Advanced Manufacturing Office, AMO) funded this work (grant number: DE-EE0001761 ). SM acknowledges the financial support from ASTM International Graduate Scholarship and The American Ceramic Society’s Forrest K. Pence Scholarship . The authors are grateful to Mr. Glenn McIntyre (HarbisonWalker International), Dr. Andus Buhr and Dr. Mark Snyder (Almatis), Mr. Timothy McGrady and Ms. Veronica Vasquez (U.S. Zinc Corporation) for generous donation of raw materials with accompanying certificate of analysis. Discussions on thermal expansion coefficient with Prof. Zi-Kui Liu (Penn State University) and with Dr. Andus Buhr on spinel and tabular alumina manufacturing are highly appreciated. The authors are grateful to Dr. Edgar Lara-Curzio, Dr. Hong Wang, Dr. James R. Keiser, and Dr. Thomas R Watkins at Oak Ridge National Laboratory for meticulously reviewing the manuscript. The US Department of Energy (Advanced Manufacturing Office, AMO) funded this work (grant number: DE-EE0001761). SM acknowledges the financial support from ASTM International Graduate Scholarship and The American Ceramic Society's Forrest K. Pence Scholarship. The authors are grateful to Mr. Glenn McIntyre (HarbisonWalker International), Dr. Andus Buhr and Dr. Mark Snyder (Almatis), Mr. Timothy McGrady and Ms. Veronica Vasquez (U.S. Zinc Corporation) for generous donation of raw materials with accompanying certificate of analysis. Discussions on thermal expansion coefficient with Prof. Zi-Kui Liu (Penn State University) and with Dr. Andus Buhr on spinel and tabular alumina manufacturing are highly appreciated. The authors are grateful to Dr. Edgar Lara-Curzio, Dr. Hong Wang, Dr. James R. Keiser, and Dr. Thomas R Watkins at Oak Ridge National Laboratory for meticulously reviewing the manuscript.
Keywords
- Refractories
- Sintering
- Spinels
- Thermal expansion
- Zinc aluminate