TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Kosanović, Darko
AU  - Stojanović, Jovica
AU  - Djordjević, Antonije
AU  - Andrić, Ljubiša
AU  - Pavlović, Vladimir
PY  - 2019
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5028
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 degrees C and holding period conducted at 1250 degrees 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 Sci Ltd, Oxford
T2  - Ceramics International
T1  - Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics
EP  - 3022
IS  - 3
SP  - 3013
VL  - 45
DO  - 10.1016/j.ceramint.2018.10.120
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Kosanović, Darko and Stojanović, Jovica and Djordjević, Antonije and Andrić, Ljubiša and Pavlović, Vladimir",
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 degrees C and holding period conducted at 1250 degrees 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 Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Effects of mechanical-activation and TiO2 addition on the behavior of two-step sintered steatite ceramics",
pages = "3022-3013",
number = "3",
volume = "45",
doi = "10.1016/j.ceramint.2018.10.120"
}

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

Terzić A, Obradović N, Kosanović D, Stojanović J, Djordjević A, Andrić L, Pavlović V. 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 .

Terzić, Anja, Obradović, Nina, Kosanović, Darko, Stojanović, Jovica, Djordjević, Antonije, Andrić, Ljubiša, Pavlović, Vladimir, "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 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Andrić, Ljubiša
AU  - Pavlović, Vladimir
AU  - Mitić, Vojislav V.
PY  - 2017
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4373
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 r(2) 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 Sci Ltd, Oxford
T2  - Ceramics International
T1  - Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling
EP  - 2562
IS  - 2
SP  - 2549
VL  - 43
DO  - 10.1016/j.ceramint.2016.11.058
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Andrić, Ljubiša and Pavlović, Vladimir 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 r(2) 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 Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling",
pages = "2562-2549",
number = "2",
volume = "43",
doi = "10.1016/j.ceramint.2016.11.058"
}

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

Terzić A, Pezo L, Andrić L, Pavlović V, 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 .

Terzić, Anja, Pezo, Lato, Andrić, Ljubiša, Pavlović, Vladimir, 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 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Stojanović, Jovica
AU  - Pavlović, Vladimir
AU  - Andrić, Ljubiša
AU  - Olcan, Dragan
AU  - Djordjević, Antonije
PY  - 2017
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4491
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 degrees to 1250 degrees 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 (epsilon(r)) and loss tangent (tan delta) 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 Sci Ltd, Oxford
T2  - Ceramics International
T1  - Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials
EP  - 13275
IS  - 16
SP  - 13264
VL  - 43
DO  - 10.1016/j.ceramint.2017.07.024
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Stojanović, Jovica and Pavlović, Vladimir and Andrić, Ljubiša and Olcan, Dragan and Djordjević, 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 degrees to 1250 degrees 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 (epsilon(r)) and loss tangent (tan delta) 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 Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials",
pages = "13275-13264",
number = "16",
volume = "43",
doi = "10.1016/j.ceramint.2017.07.024"
}

Terzić, A., Obradović, N., Stojanović, J., Pavlović, V., Andrić, L., Olcan, D.,& Djordjević, A.. (2017). Influence of different bonding and fluxing agents on the sintering behavior and dielectric properties of steatite ceramic materials. in Ceramics International
Elsevier Sci Ltd, Oxford., 43(16), 13264-13275.
https://doi.org/10.1016/j.ceramint.2017.07.024

Terzić A, Obradović N, Stojanović J, Pavlović V, Andrić L, Olcan D, Djordjević 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 .

Terzić, Anja, Obradović, Nina, Stojanović, Jovica, Pavlović, Vladimir, Andrić, Ljubiša, Olcan, Dragan, Djordjević, 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 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Obradović, Nina
AU  - Andrić, Ljubiša
AU  - Stojanović, Jovica
AU  - Pavlović, Vladimir
PY  - 2015
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/3772
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 A degrees C as adopted maximum. Mechanisms of thermally induced processes were observed by differential thermal analysis at 10, 20, and 30 A degrees 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.
PB  - Springer, Dordrecht
T2  - Journal of Thermal Analysis and Calorimetry
T1  - Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash
EP  - 1352
IS  - 2
SP  - 1339
VL  - 119
DO  - 10.1007/s10973-014-4230-4
ER  - 

@article{
author = "Terzić, Anja and Obradović, Nina and Andrić, Ljubiša and Stojanović, Jovica and Pavlović, Vladimir",
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 A degrees C as adopted maximum. Mechanisms of thermally induced processes were observed by differential thermal analysis at 10, 20, and 30 A degrees 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.",
publisher = "Springer, Dordrecht",
journal = "Journal of Thermal Analysis and Calorimetry",
title = "Investigation of thermally induced processes in corundum refractory concretes with addition of fly ash",
pages = "1352-1339",
number = "2",
volume = "119",
doi = "10.1007/s10973-014-4230-4"
}

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

Terzić A, Obradović N, Andrić L, Stojanović J, Pavlović V. 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 .

Terzić, Anja, Obradović, Nina, Andrić, Ljubiša, Stojanović, Jovica, Pavlović, Vladimir, "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 . .