Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation
Abstract
A growing demand for refractory castables with advanced properties has given rise to a continuous technological evolution and highlighted the necessity for secondary raw materials reapplication even in refractory industry. For the experiment, refractory shotcretes with the same matrix composition were prepared from 30 wt% of high aluminate cement, 40 wt% of bauxite aggregate and 30 wt% of chamotte filler. The request for obtaining a low-cement castable is fulfilled by application of mechanically activated coal ash as microfiller in one of the bauxite shotcretes. The fly ash was activated by means of vibratory disc mill and ultra-centrifugal mill, and results were compared. The shotcrete samples were dried at 110 °C during 24 h to create specimens for investigation of mechanical and thermal properties. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400 °C. At maximal 1400 °C, the bauxite shotcretes were mainly composed of a...northite, corundum, mullite and cristobalite. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis (DTA) at three different heating rates. DTA measurements showed different activation energies for ordinary bauxite shotcrete and shotcrete with microfiller. The evolution of the refractory shotcretes properties was investigated and correlated with microstructural changes induced by temperature and microfiller addition. The combination of advantages in investigated refractory shotcretes makes them suitable for use in severe conditions at high temperature applications especially in refractory industries.
Keywords:
sintering / refractories / bauxite / mechanical activation / microfillerSource:
Ceramics International, 2014, 40, 8, Part A, 12055-12065Publisher:
- Elsevier
Funding / projects:
- Directed synthesis, structure and properties of multifunctional materials (RS-172057)
- Development and application of multifunctional materials using domestic raw materials in upgraded processing lines (RS-45008)
- Implementation of new technical, technological and environmental solutions in the mining and metallurgical operations RBB and RBM (RS-33007)
DOI: 10.1016/j.ceramint.2014.04.045
ISSN: 0272-8842
WoS: 000340328600072
Scopus: 2-s2.0-84903850791
Institution/Community
Институт техничких наука САНУ / Institute of Technical Sciences of SASATY - JOUR AU - Terzić, Anja AU - Andrić, Ljubiša AU - Mitić, Vojislav V. PY - 2014 UR - https://dais.sanu.ac.rs/123456789/665 AB - A growing demand for refractory castables with advanced properties has given rise to a continuous technological evolution and highlighted the necessity for secondary raw materials reapplication even in refractory industry. For the experiment, refractory shotcretes with the same matrix composition were prepared from 30 wt% of high aluminate cement, 40 wt% of bauxite aggregate and 30 wt% of chamotte filler. The request for obtaining a low-cement castable is fulfilled by application of mechanically activated coal ash as microfiller in one of the bauxite shotcretes. The fly ash was activated by means of vibratory disc mill and ultra-centrifugal mill, and results were compared. The shotcrete samples were dried at 110 °C during 24 h to create specimens for investigation of mechanical and thermal properties. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400 °C. At maximal 1400 °C, the bauxite shotcretes were mainly composed of anorthite, corundum, mullite and cristobalite. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis (DTA) at three different heating rates. DTA measurements showed different activation energies for ordinary bauxite shotcrete and shotcrete with microfiller. The evolution of the refractory shotcretes properties was investigated and correlated with microstructural changes induced by temperature and microfiller addition. The combination of advantages in investigated refractory shotcretes makes them suitable for use in severe conditions at high temperature applications especially in refractory industries. PB - Elsevier T2 - Ceramics International T1 - Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation SP - 12055 EP - 12065 VL - 40 IS - 8, Part A DO - 10.1016/j.ceramint.2014.04.045 UR - https://hdl.handle.net/21.15107/rcub_dais_665 ER -
@article{ author = "Terzić, Anja and Andrić, Ljubiša and Mitić, Vojislav V.", year = "2014", abstract = "A growing demand for refractory castables with advanced properties has given rise to a continuous technological evolution and highlighted the necessity for secondary raw materials reapplication even in refractory industry. For the experiment, refractory shotcretes with the same matrix composition were prepared from 30 wt% of high aluminate cement, 40 wt% of bauxite aggregate and 30 wt% of chamotte filler. The request for obtaining a low-cement castable is fulfilled by application of mechanically activated coal ash as microfiller in one of the bauxite shotcretes. The fly ash was activated by means of vibratory disc mill and ultra-centrifugal mill, and results were compared. The shotcrete samples were dried at 110 °C during 24 h to create specimens for investigation of mechanical and thermal properties. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400 °C. At maximal 1400 °C, the bauxite shotcretes were mainly composed of anorthite, corundum, mullite and cristobalite. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis (DTA) at three different heating rates. DTA measurements showed different activation energies for ordinary bauxite shotcrete and shotcrete with microfiller. The evolution of the refractory shotcretes properties was investigated and correlated with microstructural changes induced by temperature and microfiller addition. The combination of advantages in investigated refractory shotcretes makes them suitable for use in severe conditions at high temperature applications especially in refractory industries.", publisher = "Elsevier", journal = "Ceramics International", title = "Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation", pages = "12055-12065", volume = "40", number = "8, Part A", doi = "10.1016/j.ceramint.2014.04.045", url = "https://hdl.handle.net/21.15107/rcub_dais_665" }
Terzić, A., Andrić, L.,& Mitić, V. V.. (2014). Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation. in Ceramics International Elsevier., 40(8, Part A), 12055-12065. https://doi.org/10.1016/j.ceramint.2014.04.045 https://hdl.handle.net/21.15107/rcub_dais_665
Terzić A, Andrić L, Mitić VV. Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation. in Ceramics International. 2014;40(8, Part A):12055-12065. doi:10.1016/j.ceramint.2014.04.045 https://hdl.handle.net/21.15107/rcub_dais_665 .
Terzić, Anja, Andrić, Ljubiša, Mitić, Vojislav V., "Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation" in Ceramics International, 40, no. 8, Part A (2014):12055-12065, https://doi.org/10.1016/j.ceramint.2014.04.045 ., https://hdl.handle.net/21.15107/rcub_dais_665 .