TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Kosanović, Darko
AU  - Stojanović, Jovica
AU  - Đorđević, Antonije
AU  - Andrić, Ljubiša
AU  - Pavlović, Vladimir B.
PY  - 2019
UR  - http://www.sciencedirect.com/science/article/pii/S0272884218329262
UR  - https://dais.sanu.ac.rs/123456789/4635
AB  - Steatite, as ceramic with composition predominantly resting on magnesium silicate, was produced from economic resources – talc, aluminosilicate clays, and either BaCO3 or feldspar as flux. Titanium dioxide was a doping agent. Four steatite mixtures were mechanically activated in a planetary ball mill for 30, 45 or 60 min, prior to the thermal treatment. Two-step sintering with initial phase set at 1350 °C and holding period conducted at 1250 °C was applied to initiate diffusion and prevent grain growth. Thereby, a high density ceramic material with low-porous submicron structure was acquired. The effects of TiO2 addition on densification, microstructure, and dielectric characteristics of steatites were monitored. The thermal stability of green mixtures was tested by differential thermal and thermogravimetric analyses. Changes in crystallinity and mineral phase composition were observed by the X-ray diffraction technique. Microstructural visualization with spatial arrangements of individual chemical elements on surface of the sintered ceramics was acquired by scanning electron microscopy accompanied with EDS mapping. In order to test the possibility of employment of the obtained steatites in insulation materials, electrical measurements were conducted by recording variations of the dielectric constant and loss tangent as a function of alternations in the mix-design and the mechanical activation period.
PB  - Elsevier
T2  - Ceramics International
T1  - Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics
SP  - 3013
EP  - 3022
VL  - 45
IS  - 3
DO  - 10.1016/j.ceramint.2018.10.120
UR  - https://hdl.handle.net/21.15107/rcub_dais_4635
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Kosanović, Darko and Stojanović, Jovica and Đorđević, Antonije and Andrić, Ljubiša and Pavlović, Vladimir B.",
year = "2019",
abstract = "Steatite, as ceramic with composition predominantly resting on magnesium silicate, was produced from economic resources – talc, aluminosilicate clays, and either BaCO3 or feldspar as flux. Titanium dioxide was a doping agent. Four steatite mixtures were mechanically activated in a planetary ball mill for 30, 45 or 60 min, prior to the thermal treatment. Two-step sintering with initial phase set at 1350 °C and holding period conducted at 1250 °C was applied to initiate diffusion and prevent grain growth. Thereby, a high density ceramic material with low-porous submicron structure was acquired. The effects of TiO2 addition on densification, microstructure, and dielectric characteristics of steatites were monitored. The thermal stability of green mixtures was tested by differential thermal and thermogravimetric analyses. Changes in crystallinity and mineral phase composition were observed by the X-ray diffraction technique. Microstructural visualization with spatial arrangements of individual chemical elements on surface of the sintered ceramics was acquired by scanning electron microscopy accompanied with EDS mapping. In order to test the possibility of employment of the obtained steatites in insulation materials, electrical measurements were conducted by recording variations of the dielectric constant and loss tangent as a function of alternations in the mix-design and the mechanical activation period.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics",
pages = "3013-3022",
volume = "45",
number = "3",
doi = "10.1016/j.ceramint.2018.10.120",
url = "https://hdl.handle.net/21.15107/rcub_dais_4635"
}

Terzić, A., Obradović, N., Kosanović, D., Stojanović, J., Đorđević, A., Andrić, L.,& Pavlović, V. B.. (2019). Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics. in Ceramics International
Elsevier., 45(3), 3013-3022.
https://doi.org/10.1016/j.ceramint.2018.10.120
https://hdl.handle.net/21.15107/rcub_dais_4635

Terzić A, Obradović N, Kosanović D, Stojanović J, Đorđević A, Andrić L, Pavlović VB. Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics. in Ceramics International. 2019;45(3):3013-3022.
doi:10.1016/j.ceramint.2018.10.120
https://hdl.handle.net/21.15107/rcub_dais_4635 .

Terzić, Anja, Obradović, Nina, Kosanović, Darko, Stojanović, Jovica, Đorđević, Antonije, Andrić, Ljubiša, Pavlović, Vladimir B., "Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics" in Ceramics International, 45, no. 3 (2019):3013-3022,
https://doi.org/10.1016/j.ceramint.2018.10.120 .,
https://hdl.handle.net/21.15107/rcub_dais_4635 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Kosanović, Darko
AU  - Stojanović, Jovica
AU  - Đorđević, Antonije
AU  - Andrić, Ljubiša
AU  - Pavlović, Vladimir B.
PY  - 2019
UR  - http://www.sciencedirect.com/science/article/pii/S0272884218329262
UR  - https://dais.sanu.ac.rs/123456789/4645
AB  - Steatite, as ceramic with composition predominantly resting on magnesium silicate, was produced from economic resources – talc, aluminosilicate clays, and either BaCO3 or feldspar as flux. Titanium dioxide was a doping agent. Four steatite mixtures were mechanically activated in a planetary ball mill for 30, 45 or 60 min, prior to the thermal treatment. Two-step sintering with initial phase set at 1350 °C and holding period conducted at 1250 °C was applied to initiate diffusion and prevent grain growth. Thereby, a high density ceramic material with low-porous submicron structure was acquired. The effects of TiO2 addition on densification, microstructure, and dielectric characteristics of steatites were monitored. The thermal stability of green mixtures was tested by differential thermal and thermogravimetric analyses. Changes in crystallinity and mineral phase composition were observed by the X-ray diffraction technique. Microstructural visualization with spatial arrangements of individual chemical elements on surface of the sintered ceramics was acquired by scanning electron microscopy accompanied with EDS mapping. In order to test the possibility of employment of the obtained steatites in insulation materials, electrical measurements were conducted by recording variations of the dielectric constant and loss tangent as a function of alternations in the mix-design and the mechanical activation period.
PB  - Elsevier
T2  - Ceramics International
T1  - Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics
SP  - 3013
EP  - 3022
VL  - 45
IS  - 3
DO  - 10.1016/j.ceramint.2018.10.120
UR  - https://hdl.handle.net/21.15107/rcub_dais_4645
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Kosanović, Darko and Stojanović, Jovica and Đorđević, Antonije and Andrić, Ljubiša and Pavlović, Vladimir B.",
year = "2019",
abstract = "Steatite, as ceramic with composition predominantly resting on magnesium silicate, was produced from economic resources – talc, aluminosilicate clays, and either BaCO3 or feldspar as flux. Titanium dioxide was a doping agent. Four steatite mixtures were mechanically activated in a planetary ball mill for 30, 45 or 60 min, prior to the thermal treatment. Two-step sintering with initial phase set at 1350 °C and holding period conducted at 1250 °C was applied to initiate diffusion and prevent grain growth. Thereby, a high density ceramic material with low-porous submicron structure was acquired. The effects of TiO2 addition on densification, microstructure, and dielectric characteristics of steatites were monitored. The thermal stability of green mixtures was tested by differential thermal and thermogravimetric analyses. Changes in crystallinity and mineral phase composition were observed by the X-ray diffraction technique. Microstructural visualization with spatial arrangements of individual chemical elements on surface of the sintered ceramics was acquired by scanning electron microscopy accompanied with EDS mapping. In order to test the possibility of employment of the obtained steatites in insulation materials, electrical measurements were conducted by recording variations of the dielectric constant and loss tangent as a function of alternations in the mix-design and the mechanical activation period.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics",
pages = "3013-3022",
volume = "45",
number = "3",
doi = "10.1016/j.ceramint.2018.10.120",
url = "https://hdl.handle.net/21.15107/rcub_dais_4645"
}

Terzić, A., Obradović, N., Kosanović, D., Stojanović, J., Đorđević, A., Andrić, L.,& Pavlović, V. B.. (2019). Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics. in Ceramics International
Elsevier., 45(3), 3013-3022.
https://doi.org/10.1016/j.ceramint.2018.10.120
https://hdl.handle.net/21.15107/rcub_dais_4645

Terzić A, Obradović N, Kosanović D, Stojanović J, Đorđević A, Andrić L, Pavlović VB. Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics. in Ceramics International. 2019;45(3):3013-3022.
doi:10.1016/j.ceramint.2018.10.120
https://hdl.handle.net/21.15107/rcub_dais_4645 .

Terzić, Anja, Obradović, Nina, Kosanović, Darko, Stojanović, Jovica, Đorđević, Antonije, Andrić, Ljubiša, Pavlović, Vladimir B., "Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics" in Ceramics International, 45, no. 3 (2019):3013-3022,
https://doi.org/10.1016/j.ceramint.2018.10.120 .,
https://hdl.handle.net/21.15107/rcub_dais_4645 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Stojanović, Jovica
AU  - Pavlović, Vladimir B.
AU  - Andrić, Ljubiša
AU  - Olćan, Dragan
AU  - Đorđević, Antonije
PY  - 2017
UR  - https://dais.sanu.ac.rs/123456789/2356
AB  - The focus of the study was on providing insights into interconnections between sintering and development of the crystalline microstructure, and consequently variations in dielectric behavior of four steatites fabricated from a low-cost raw material, i.e. talc. The changes, induced by the alternations of the binders (bentonite, kaolin clay) and fluxing agents (BaCO3, feldspar), were monitored in the temperature range 1000° to 1250 °C in which complete densification and re-crystallization of the investigated structures were accomplished. The critical points in the synthesis of steatite materials were assessed by instrumental analyses. Crystallinity changes and mineral phase transition during sintering were monitored by X-ray diffraction technique. Microstructural visualization of the samples and the spatial arrangements of individual chemical elements were achieved via scanning electron microscopy accompanied with EDS mapping. The thermal stability was observed on the green mixtures using differential thermal and thermo gravimetric analyses. Electrical measurements recorded variations of the dielectric constant (εr) and loss tangent (tan δ) as a function of the sintering temperature. The investigation highlighted critical design points, as well as the optimal combinations of the raw materials for production of the steatite ceramics for advanced electrical engineering applications.
PB  - Elsevier
T2  - Ceramics International
T1  - Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials
SP  - 13264
EP  - 13275
VL  - 43
IS  - 16
DO  - 10.1016/j.ceramint.2017.07.024
UR  - https://hdl.handle.net/21.15107/rcub_dais_2356
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Stojanović, Jovica and Pavlović, Vladimir B. and Andrić, Ljubiša and Olćan, Dragan and Đorđević, Antonije",
year = "2017",
abstract = "The focus of the study was on providing insights into interconnections between sintering and development of the crystalline microstructure, and consequently variations in dielectric behavior of four steatites fabricated from a low-cost raw material, i.e. talc. The changes, induced by the alternations of the binders (bentonite, kaolin clay) and fluxing agents (BaCO3, feldspar), were monitored in the temperature range 1000° to 1250 °C in which complete densification and re-crystallization of the investigated structures were accomplished. The critical points in the synthesis of steatite materials were assessed by instrumental analyses. Crystallinity changes and mineral phase transition during sintering were monitored by X-ray diffraction technique. Microstructural visualization of the samples and the spatial arrangements of individual chemical elements were achieved via scanning electron microscopy accompanied with EDS mapping. The thermal stability was observed on the green mixtures using differential thermal and thermo gravimetric analyses. Electrical measurements recorded variations of the dielectric constant (εr) and loss tangent (tan δ) as a function of the sintering temperature. The investigation highlighted critical design points, as well as the optimal combinations of the raw materials for production of the steatite ceramics for advanced electrical engineering applications.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials",
pages = "13264-13275",
volume = "43",
number = "16",
doi = "10.1016/j.ceramint.2017.07.024",
url = "https://hdl.handle.net/21.15107/rcub_dais_2356"
}

Terzić, A., Obradović, N., Stojanović, J., Pavlović, V. B., Andrić, L., Olćan, D.,& Đorđević, A.. (2017). Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials. in Ceramics International
Elsevier., 43(16), 13264-13275.
https://doi.org/10.1016/j.ceramint.2017.07.024
https://hdl.handle.net/21.15107/rcub_dais_2356

Terzić A, Obradović N, Stojanović J, Pavlović VB, Andrić L, Olćan D, Đorđević A. Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials. in Ceramics International. 2017;43(16):13264-13275.
doi:10.1016/j.ceramint.2017.07.024
https://hdl.handle.net/21.15107/rcub_dais_2356 .

Terzić, Anja, Obradović, Nina, Stojanović, Jovica, Pavlović, Vladimir B., Andrić, Ljubiša, Olćan, Dragan, Đorđević, Antonije, "Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials" in Ceramics International, 43, no. 16 (2017):13264-13275,
https://doi.org/10.1016/j.ceramint.2017.07.024 .,
https://hdl.handle.net/21.15107/rcub_dais_2356 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Andrić, Ljubiša
AU  - Pavlović, Vladimir B.
AU  - Mitić, Vojislav V.
PY  - 2017
UR  - https://dais.sanu.ac.rs/123456789/2350
AB  - The properties of seven montmorillonite-rich bentonites of different geological origin were investigated prior and subsequent to mechano-chemical processing in an ultra-centrifugal mill. The objective of the experiment was altering the bentonite types and activation parameters in order to determine the optimal milling conditions that produce material which is physico-mechanically and microstructurally applicable as a binder replacement and sorbent in the construction composites. The efficiency of bentonite activation was assessed by chemometrics and Artificial neural networks mathematical modeling. Principal component analysis and analysis of variance were used in the observation of the influence of input variables (bentonite chemical composition) and process parameters (milling duration, rotor velocity) on the product characteristics: density, specific surface area, grain size and distribution, cation exchange capacity, melting point, compressive strength, shrinkage and porosity. When the ANN models for the observed responses, related to predicted bentonite characteristics and quality, were compared to experimental results, they correctly predicted the responses. The processed data also adequately fitted to the regression second order polynomial models. The SOP models, which showed r2 values from 0.357 to 0.948, and were able to predict the observed responses in a wide range of processing parameters, while ANN models performed high prediction accuracy (0.776–0.901) and can be considered as precise for response variables prediction. The combination of the conducted mathematical analyses showed that that increase/decrease in output values was stabilized after 30 min of activation. Mathematically attained interpretations were correlated with the results of the instrumental analyses (XRD, DTA/TG, SEM) to confirm the adoption of B6 bentonite as a preferable type and 30 min as an optimal milling time for acquiring quality of clay powder that will be used in structural and thermal applications.
PB  - Elsevier
T2  - Ceramics International
T1  - Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling
SP  - 2549
EP  - 2562
VL  - 43
IS  - 2
DO  - 10.1016/j.ceramint.2016.11.058
UR  - https://hdl.handle.net/21.15107/rcub_dais_2350
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Andrić, Ljubiša and Pavlović, Vladimir B. and Mitić, Vojislav V.",
year = "2017",
abstract = "The properties of seven montmorillonite-rich bentonites of different geological origin were investigated prior and subsequent to mechano-chemical processing in an ultra-centrifugal mill. The objective of the experiment was altering the bentonite types and activation parameters in order to determine the optimal milling conditions that produce material which is physico-mechanically and microstructurally applicable as a binder replacement and sorbent in the construction composites. The efficiency of bentonite activation was assessed by chemometrics and Artificial neural networks mathematical modeling. Principal component analysis and analysis of variance were used in the observation of the influence of input variables (bentonite chemical composition) and process parameters (milling duration, rotor velocity) on the product characteristics: density, specific surface area, grain size and distribution, cation exchange capacity, melting point, compressive strength, shrinkage and porosity. When the ANN models for the observed responses, related to predicted bentonite characteristics and quality, were compared to experimental results, they correctly predicted the responses. The processed data also adequately fitted to the regression second order polynomial models. The SOP models, which showed r2 values from 0.357 to 0.948, and were able to predict the observed responses in a wide range of processing parameters, while ANN models performed high prediction accuracy (0.776–0.901) and can be considered as precise for response variables prediction. The combination of the conducted mathematical analyses showed that that increase/decrease in output values was stabilized after 30 min of activation. Mathematically attained interpretations were correlated with the results of the instrumental analyses (XRD, DTA/TG, SEM) to confirm the adoption of B6 bentonite as a preferable type and 30 min as an optimal milling time for acquiring quality of clay powder that will be used in structural and thermal applications.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling",
pages = "2549-2562",
volume = "43",
number = "2",
doi = "10.1016/j.ceramint.2016.11.058",
url = "https://hdl.handle.net/21.15107/rcub_dais_2350"
}

Terzić, A., Pezo, L., Andrić, L., Pavlović, V. B.,& Mitić, V. V.. (2017). Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling. in Ceramics International
Elsevier., 43(2), 2549-2562.
https://doi.org/10.1016/j.ceramint.2016.11.058
https://hdl.handle.net/21.15107/rcub_dais_2350

Terzić A, Pezo L, Andrić L, Pavlović VB, Mitić VV. Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling. in Ceramics International. 2017;43(2):2549-2562.
doi:10.1016/j.ceramint.2016.11.058
https://hdl.handle.net/21.15107/rcub_dais_2350 .

Terzić, Anja, Pezo, Lato, Andrić, Ljubiša, Pavlović, Vladimir B., Mitić, Vojislav V., "Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling" in Ceramics International, 43, no. 2 (2017):2549-2562,
https://doi.org/10.1016/j.ceramint.2016.11.058 .,
https://hdl.handle.net/21.15107/rcub_dais_2350 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Andrić, Ljubiša
AU  - Stojanović, Jovica
AU  - Pavlović, Vladimir B.
PY  - 2015
UR  - https://dais.sanu.ac.rs/123456789/3545
AB  - The effects that the fly ash addition has on the behavior of thermally resistant corundum concrete were discussed. Experimental program implied production of two refractory composites: "referent" concrete from 20 % of high-aluminate cement and 80 % of corundum aggregate, "recycled" concrete from 10 % of high-aluminate cement, 20 % of lignite coal ash, and 70 % of corundum aggregate. The fly ash was mechanically activated by a vibratory disk mill. In the concrete matrix, the ash had a role of cement partial replacement and microfiller. The mechanical and thermal properties of the concretes were studied at temperatures ranging from ambient to 1,400 °C as adopted maximum. Mechanisms of thermally induced processes were observed by differential thermal analysis at 10, 20, and 30 °C min-1 heating rates. Referent and recycled concretes showed differences in calculated activation energies. The variations in refractory concretes performances were discussed with support of scanning electron microscope imagining and X-ray diffraction results. The recycled ash concrete exhibited properties that met the requirements for the castables, which proves it suitable for use in severe conditions at high temperature and highlights the reusing principle and possibility of cleaner and economically sustainable production. © 2014 Akadémiai Kiadó, Budapest, Hungary.
PB  - Springer Netherlands
T2  - Journal of Thermal Analysis and Calorimetry
T1  - Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash
SP  - 1339
EP  - 1352
VL  - 119
IS  - 2
DO  - 10.1007/s10973-014-4230-4
UR  - https://hdl.handle.net/21.15107/rcub_dais_3545
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Andrić, Ljubiša and Stojanović, Jovica and Pavlović, Vladimir B.",
year = "2015",
abstract = "The effects that the fly ash addition has on the behavior of thermally resistant corundum concrete were discussed. Experimental program implied production of two refractory composites: "referent" concrete from 20 % of high-aluminate cement and 80 % of corundum aggregate, "recycled" concrete from 10 % of high-aluminate cement, 20 % of lignite coal ash, and 70 % of corundum aggregate. The fly ash was mechanically activated by a vibratory disk mill. In the concrete matrix, the ash had a role of cement partial replacement and microfiller. The mechanical and thermal properties of the concretes were studied at temperatures ranging from ambient to 1,400 °C as adopted maximum. Mechanisms of thermally induced processes were observed by differential thermal analysis at 10, 20, and 30 °C min-1 heating rates. Referent and recycled concretes showed differences in calculated activation energies. The variations in refractory concretes performances were discussed with support of scanning electron microscope imagining and X-ray diffraction results. The recycled ash concrete exhibited properties that met the requirements for the castables, which proves it suitable for use in severe conditions at high temperature and highlights the reusing principle and possibility of cleaner and economically sustainable production. © 2014 Akadémiai Kiadó, Budapest, Hungary.",
publisher = "Springer Netherlands",
journal = "Journal of Thermal Analysis and Calorimetry",
title = "Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash",
pages = "1339-1352",
volume = "119",
number = "2",
doi = "10.1007/s10973-014-4230-4",
url = "https://hdl.handle.net/21.15107/rcub_dais_3545"
}

Terzić, A., Obradović, N., Andrić, L., Stojanović, J.,& Pavlović, V. B.. (2015). Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash. in Journal of Thermal Analysis and Calorimetry
Springer Netherlands., 119(2), 1339-1352.
https://doi.org/10.1007/s10973-014-4230-4
https://hdl.handle.net/21.15107/rcub_dais_3545

Terzić A, Obradović N, Andrić L, Stojanović J, Pavlović VB. Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash. in Journal of Thermal Analysis and Calorimetry. 2015;119(2):1339-1352.
doi:10.1007/s10973-014-4230-4
https://hdl.handle.net/21.15107/rcub_dais_3545 .

Terzić, Anja, Obradović, Nina, Andrić, Ljubiša, Stojanović, Jovica, Pavlović, Vladimir B., "Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash" in Journal of Thermal Analysis and Calorimetry, 119, no. 2 (2015):1339-1352,
https://doi.org/10.1007/s10973-014-4230-4 .,
https://hdl.handle.net/21.15107/rcub_dais_3545 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Andrić, Ljubiša
AU  - Mitić, Vojislav
PY  - 2015
UR  - https://dais.sanu.ac.rs/123456789/3525
AB  - The impact of the mechanical processing parameters on the alumina grain-size distribution affiliated characteristics and on the γ to α phase transformation rate was investigated. The moderation in the alumina samples behavior has been correlated to the granulometric and mineralogical changes induced by activation via an ultra-centrifugal mill. The assessment of the activation process variables influence on the final quality of the product parameters was conveyed in order to optimize the mechanical treatment of the alumina, which otherwise could be regarded as either energetically or economically unsustainable procedure. The Response Surface Method, Standard Score Analysis and Principal Component Analysis were applied as means of the mechanical activation optimization. The r 2 values obtained by developed models were in range from 0.816 to 0.988. The established mathematical models were able to precisely predict the quality parameters in a broad range of processing parameters. The Standard Score Analysis emphasized that the optimal output sample was obtained using a sieve mesh of 120μm set of processing parameters (SS=0.96). Diverse comparison analyses disclosed that the optimal set of activation process parameters could reduce the negative effect of γ-alumina samples immanent properties on the final score, and furthermore to enhance the rate of γ to α transition which would improve energetic and economic sustainability of the alumina phase transformation procedure. © 2015 Elsevier Ltd and Techna Group S.r.l.
PB  - Elsevier
T2  - Ceramics International
T1  - Analytical modeling of activation procedure applied in α-alumina thermo-mechanical synthesis
SP  - 11908
EP  - 11917
VL  - 41
IS  - 9, Part B
DO  - 10.1016/j.ceramint.2015.05.158
UR  - https://hdl.handle.net/21.15107/rcub_dais_3525
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Andrić, Ljubiša and Mitić, Vojislav",
year = "2015",
abstract = "The impact of the mechanical processing parameters on the alumina grain-size distribution affiliated characteristics and on the γ to α phase transformation rate was investigated. The moderation in the alumina samples behavior has been correlated to the granulometric and mineralogical changes induced by activation via an ultra-centrifugal mill. The assessment of the activation process variables influence on the final quality of the product parameters was conveyed in order to optimize the mechanical treatment of the alumina, which otherwise could be regarded as either energetically or economically unsustainable procedure. The Response Surface Method, Standard Score Analysis and Principal Component Analysis were applied as means of the mechanical activation optimization. The r 2 values obtained by developed models were in range from 0.816 to 0.988. The established mathematical models were able to precisely predict the quality parameters in a broad range of processing parameters. The Standard Score Analysis emphasized that the optimal output sample was obtained using a sieve mesh of 120μm set of processing parameters (SS=0.96). Diverse comparison analyses disclosed that the optimal set of activation process parameters could reduce the negative effect of γ-alumina samples immanent properties on the final score, and furthermore to enhance the rate of γ to α transition which would improve energetic and economic sustainability of the alumina phase transformation procedure. © 2015 Elsevier Ltd and Techna Group S.r.l.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Analytical modeling of activation procedure applied in α-alumina thermo-mechanical synthesis",
pages = "11908-11917",
volume = "41",
number = "9, Part B",
doi = "10.1016/j.ceramint.2015.05.158",
url = "https://hdl.handle.net/21.15107/rcub_dais_3525"
}

Terzić, A., Pezo, L., Andrić, L.,& Mitić, V.. (2015). Analytical modeling of activation procedure applied in α-alumina thermo-mechanical synthesis. in Ceramics International
Elsevier., 41(9, Part B), 11908-11917.
https://doi.org/10.1016/j.ceramint.2015.05.158
https://hdl.handle.net/21.15107/rcub_dais_3525

Terzić A, Pezo L, Andrić L, Mitić V. Analytical modeling of activation procedure applied in α-alumina thermo-mechanical synthesis. in Ceramics International. 2015;41(9, Part B):11908-11917.
doi:10.1016/j.ceramint.2015.05.158
https://hdl.handle.net/21.15107/rcub_dais_3525 .

Terzić, Anja, Pezo, Lato, Andrić, Ljubiša, Mitić, Vojislav, "Analytical modeling of activation procedure applied in α-alumina thermo-mechanical synthesis" in Ceramics International, 41, no. 9, Part B (2015):11908-11917,
https://doi.org/10.1016/j.ceramint.2015.05.158 .,
https://hdl.handle.net/21.15107/rcub_dais_3525 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Andrić, Ljubiša
AU  - Stojanović, J.
AU  - Obradović, Nina
AU  - Kostović, M.
PY  - 2014
UR  - https://dais.sanu.ac.rs/123456789/667
AB  - The effect of vibratory mill induced mechanical activation on the change of the particle size, crystallinity and the phase transformations of the minerals present in the activated material, was studied with the purpose of decreasing of the sintering temperature of talc (Mg3Si4O10(OH)2) as raw material which is the basic component of the steatite ceramics. The aims of the conducted investigation were, also, increasing of the reactivity of the comminuted raw material and establishing of the optimal activation period. The properties of the activated talc induced by mechanical force were expressed in form of the grain inertia change which was measured by means of automatic grain counter. Mechanically activated grains are the most convenient mineral form for physical concentration since the energy change of the mill-material system is recorded on them. The effect of dry grinding on the structure, particle size and shape of talc was studied by means of XRD, DTA and SEM/EDS methods. Activation of talc produced an increase of the starting surface area value progressively from 4.5 m2/g up to a maximum of 108.5 m2/g achieved at 30 min. A subsequent decrease of rate of surface area change and the rate of size reduction were observed following the prolonged grinding. Talc activated in vibratory mill for optimal 30 min showed properties which positively influence the decrease of sintering temperature and the increase of the sintering rate of steatite ceramics. [Projekat Ministarstva nauke Republike Srbije, br. 172057, br. 45008 i br. 33007]
PB  - Belgrade : Interenational Institute for the Science of Sintering
T2  - Science of Sintering
T1  - Mechanical activation as sintering pre-treatment of talc for steatite ceramics
SP  - 247
EP  - 258
VL  - 46
IS  - 2
DO  - 10.2298/SOS1402247T
UR  - https://hdl.handle.net/21.15107/rcub_dais_667
ER  - 

@article{
author = "Terzić, Anja and Andrić, Ljubiša and Stojanović, J. and Obradović, Nina and Kostović, M.",
year = "2014",
abstract = "The effect of vibratory mill induced mechanical activation on the change of the particle size, crystallinity and the phase transformations of the minerals present in the activated material, was studied with the purpose of decreasing of the sintering temperature of talc (Mg3Si4O10(OH)2) as raw material which is the basic component of the steatite ceramics. The aims of the conducted investigation were, also, increasing of the reactivity of the comminuted raw material and establishing of the optimal activation period. The properties of the activated talc induced by mechanical force were expressed in form of the grain inertia change which was measured by means of automatic grain counter. Mechanically activated grains are the most convenient mineral form for physical concentration since the energy change of the mill-material system is recorded on them. The effect of dry grinding on the structure, particle size and shape of talc was studied by means of XRD, DTA and SEM/EDS methods. Activation of talc produced an increase of the starting surface area value progressively from 4.5 m2/g up to a maximum of 108.5 m2/g achieved at 30 min. A subsequent decrease of rate of surface area change and the rate of size reduction were observed following the prolonged grinding. Talc activated in vibratory mill for optimal 30 min showed properties which positively influence the decrease of sintering temperature and the increase of the sintering rate of steatite ceramics. [Projekat Ministarstva nauke Republike Srbije, br. 172057, br. 45008 i br. 33007]",
publisher = "Belgrade : Interenational Institute for the Science of Sintering",
journal = "Science of Sintering",
title = "Mechanical activation as sintering pre-treatment of talc for steatite ceramics",
pages = "247-258",
volume = "46",
number = "2",
doi = "10.2298/SOS1402247T",
url = "https://hdl.handle.net/21.15107/rcub_dais_667"
}

Terzić, A., Andrić, L., Stojanović, J., Obradović, N.,& Kostović, M.. (2014). Mechanical activation as sintering pre-treatment of talc for steatite ceramics. in Science of Sintering
Belgrade : Interenational Institute for the Science of Sintering., 46(2), 247-258.
https://doi.org/10.2298/SOS1402247T
https://hdl.handle.net/21.15107/rcub_dais_667

Terzić A, Andrić L, Stojanović J, Obradović N, Kostović M. Mechanical activation as sintering pre-treatment of talc for steatite ceramics. in Science of Sintering. 2014;46(2):247-258.
doi:10.2298/SOS1402247T
https://hdl.handle.net/21.15107/rcub_dais_667 .

Terzić, Anja, Andrić, Ljubiša, Stojanović, J., Obradović, Nina, Kostović, M., "Mechanical activation as sintering pre-treatment of talc for steatite ceramics" in Science of Sintering, 46, no. 2 (2014):247-258,
https://doi.org/10.2298/SOS1402247T .,
https://hdl.handle.net/21.15107/rcub_dais_667 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Andrić, Ljubiša
AU  - Mitić, Vojislav V.
PY  - 2014
UR  - https://dais.sanu.ac.rs/123456789/666
AB  - In this study, the feasibility of alumina phase transition enhancement by mechanical activation was conducted. It was showed that the milling environment plays an important role on the physical, chemical and thermal behavior of the alumina powder utilized as refractory component material. The aim of the investigation was to increase the reactivity of the starting γ-Al2O3 by mechanical treatment in two types of high-energy activators – vibratory disc mill and vibratory ball mill. In continuation, the decrease of the subsequent sintering temperature as well as the treatment duration would be induced by making the transition into final thermo-stable α-Al2O3 modification easier and faster. Full factorial experiment was conducted and the results were analyzed by the proposed mathematical model in order to understand the effects of the activation process variables on the amount and physical characteristics of the synthesized (activated and subsequently thermally treated) product and to establish the optimal activation period. As the result of the analysis, operation parameters of the activator and activation period were found to be the most important factors. The initial γ-Al2O3 and synthesized α-Al2O3 were thoroughly analyzed by DTA, XRD, IR and SEM methods. Thermal behavior of γ and α-modification were studied by differential thermal analysis conducted in the same environment, under same heating rates. X-ray diffraction analysis gave reliable identification of the crystal phases and changes in crystallinity of treated alumina. Based on XRD peak intensity measurements, the γ-Al2O3 almost completely passed (95%) into α-Al2O3 after 180 min of activation in vibratory ball mill and subsequent thermal treatment (2 h/1200 °C). SEM microphotographs with accompanying image analysis PC program highlighted changes in size and shape of particles of initial and synthesized Al2O3. Synthesized Al2O3 exquisite thermal behavior characteristic for refractory compounds, demonstrated that it is possible to obtain α-alumina at lower transformation temperatures in shorter time intervals by applying mechanical activation.
PB  - Elsevier
T2  - Ceramics International
T1  - Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of γ to α phase transformation mechanism
SP  - 14851
EP  - 14863
VL  - 40
IS  - 8 Part B
DO  - 10.1016/j.ceramint.2014.06.080
UR  - https://hdl.handle.net/21.15107/rcub_dais_666
ER  - 

@article{
author = "Terzić, Anja and Andrić, Ljubiša and Mitić, Vojislav V.",
year = "2014",
abstract = "In this study, the feasibility of alumina phase transition enhancement by mechanical activation was conducted. It was showed that the milling environment plays an important role on the physical, chemical and thermal behavior of the alumina powder utilized as refractory component material. The aim of the investigation was to increase the reactivity of the starting γ-Al2O3 by mechanical treatment in two types of high-energy activators – vibratory disc mill and vibratory ball mill. In continuation, the decrease of the subsequent sintering temperature as well as the treatment duration would be induced by making the transition into final thermo-stable α-Al2O3 modification easier and faster. Full factorial experiment was conducted and the results were analyzed by the proposed mathematical model in order to understand the effects of the activation process variables on the amount and physical characteristics of the synthesized (activated and subsequently thermally treated) product and to establish the optimal activation period. As the result of the analysis, operation parameters of the activator and activation period were found to be the most important factors. The initial γ-Al2O3 and synthesized α-Al2O3 were thoroughly analyzed by DTA, XRD, IR and SEM methods. Thermal behavior of γ and α-modification were studied by differential thermal analysis conducted in the same environment, under same heating rates. X-ray diffraction analysis gave reliable identification of the crystal phases and changes in crystallinity of treated alumina. Based on XRD peak intensity measurements, the γ-Al2O3 almost completely passed (95%) into α-Al2O3 after 180 min of activation in vibratory ball mill and subsequent thermal treatment (2 h/1200 °C). SEM microphotographs with accompanying image analysis PC program highlighted changes in size and shape of particles of initial and synthesized Al2O3. Synthesized Al2O3 exquisite thermal behavior characteristic for refractory compounds, demonstrated that it is possible to obtain α-alumina at lower transformation temperatures in shorter time intervals by applying mechanical activation.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of γ to α phase transformation mechanism",
pages = "14851-14863",
volume = "40",
number = "8 Part B",
doi = "10.1016/j.ceramint.2014.06.080",
url = "https://hdl.handle.net/21.15107/rcub_dais_666"
}

Terzić, A., Andrić, L.,& Mitić, V. V.. (2014). Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of γ to α phase transformation mechanism. in Ceramics International
Elsevier., 40(8 Part B), 14851-14863.
https://doi.org/10.1016/j.ceramint.2014.06.080
https://hdl.handle.net/21.15107/rcub_dais_666

Terzić A, Andrić L, Mitić VV. Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of γ to α phase transformation mechanism. in Ceramics International. 2014;40(8 Part B):14851-14863.
doi:10.1016/j.ceramint.2014.06.080
https://hdl.handle.net/21.15107/rcub_dais_666 .

Terzić, Anja, Andrić, Ljubiša, Mitić, Vojislav V., "Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of γ to α phase transformation mechanism" in Ceramics International, 40, no. 8 Part B (2014):14851-14863,
https://doi.org/10.1016/j.ceramint.2014.06.080 .,
https://hdl.handle.net/21.15107/rcub_dais_666 .

TY  - 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 .

TY  - CONF
AU  - Terzić, Anja
AU  - Radojević, Zagorka
AU  - Miličić, Ljiljana
AU  - Obradović, Nina
AU  - Andrić, Ljubiša
PY  - 2014
UR  - https://dais.sanu.ac.rs/123456789/604
AB  - The necessity for application of activated secondary raw materials in refractory industry is caused by a growing demand for refractory castables with advanced properties and continuous technological evolution of high-temperature materials. In this investigation, refractory shotcretes with the same matrix composition were prepared from 15 wt.% of high aluminate cement and 45 wt.% of bauxite aggregate + 30 wt.% of chamotte filler, i.e. 75% of corundum aggregate. The request for obtaining a low-cement castable is fulfilled by application of 10 wt.% of mechanically activated coal ash as the cement substitution in the shotcretes. The ash was activated by means of various high energy mechano-activators. Results were compared in order to choose the most efficient activation procedure. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400°C. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis at three different heating rates. The measurements showed different activation energies for ordinary shotcretes and shotcretes with activated ash. The evolution of the refractory shotcretes properties was investigated and correlated to 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  - Belgrade : Serbian Ceramic Society
C3  - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts / III Serbian Ceramic Society Conference, 29th September - 1st October, Belgrade, 2014
T1  - Corundum and Bauxite Refractory Shotcretes based on Activated Waste Coal Ash: Investigation of Thermally Induced Properties Change
SP  - 70
EP  - 70
UR  - https://hdl.handle.net/21.15107/rcub_dais_604
ER  - 

@conference{
author = "Terzić, Anja and Radojević, Zagorka and Miličić, Ljiljana and Obradović, Nina and Andrić, Ljubiša",
year = "2014",
abstract = "The necessity for application of activated secondary raw materials in refractory industry is caused by a growing demand for refractory castables with advanced properties and continuous technological evolution of high-temperature materials. In this investigation, refractory shotcretes with the same matrix composition were prepared from 15 wt.% of high aluminate cement and 45 wt.% of bauxite aggregate + 30 wt.% of chamotte filler, i.e. 75% of corundum aggregate. The request for obtaining a low-cement castable is fulfilled by application of 10 wt.% of mechanically activated coal ash as the cement substitution in the shotcretes. The ash was activated by means of various high energy mechano-activators. Results were compared in order to choose the most efficient activation procedure. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400°C. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis at three different heating rates. The measurements showed different activation energies for ordinary shotcretes and shotcretes with activated ash. The evolution of the refractory shotcretes properties was investigated and correlated to 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 = "Belgrade : Serbian Ceramic Society",
journal = "Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts / III Serbian Ceramic Society Conference, 29th September - 1st October, Belgrade, 2014",
title = "Corundum and Bauxite Refractory Shotcretes based on Activated Waste Coal Ash: Investigation of Thermally Induced Properties Change",
pages = "70-70",
url = "https://hdl.handle.net/21.15107/rcub_dais_604"
}

Terzić, A., Radojević, Z., Miličić, L., Obradović, N.,& Andrić, L.. (2014). Corundum and Bauxite Refractory Shotcretes based on Activated Waste Coal Ash: Investigation of Thermally Induced Properties Change. in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts / III Serbian Ceramic Society Conference, 29th September - 1st October, Belgrade, 2014
Belgrade : Serbian Ceramic Society., 70-70.
https://hdl.handle.net/21.15107/rcub_dais_604

Terzić A, Radojević Z, Miličić L, Obradović N, Andrić L. Corundum and Bauxite Refractory Shotcretes based on Activated Waste Coal Ash: Investigation of Thermally Induced Properties Change. in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts / III Serbian Ceramic Society Conference, 29th September - 1st October, Belgrade, 2014. 2014;:70-70.
https://hdl.handle.net/21.15107/rcub_dais_604 .

Terzić, Anja, Radojević, Zagorka, Miličić, Ljiljana, Obradović, Nina, Andrić, Ljubiša, "Corundum and Bauxite Refractory Shotcretes based on Activated Waste Coal Ash: Investigation of Thermally Induced Properties Change" in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts / III Serbian Ceramic Society Conference, 29th September - 1st October, Belgrade, 2014 (2014):70-70,
https://hdl.handle.net/21.15107/rcub_dais_604 .