TY  - CONF
AU  - Đorđević, Nataša
AU  - Obradović, Nina
AU  - Sokić, Miroslav D.
AU  - Marković, Branislav R.
AU  - Patarić, Aleksandra
AU  - Petronijević, Nela
PY  - 2019
UR  - https://dais.sanu.ac.rs/123456789/14867
AB  - Mechanochemical activation of 2MgO•2Al2O3•5SiO2, starting components of cordierite, was used in aim to decrease the sintering temperature. Cordierite is very attractive ceramic material due to its properties, excellent thermal shock resistance, low dielectric constants (~5) and low thermal expansions (20•10-7 ºC-1). Specific surface area of the activated components was detected by the BET method. TG and DTA methods have followed behaviors of the three-component system. To see the influence of relaxation time on the activated components, FT IR has analyzed the starting components as well as activated mixture after 24h and 24 months. TG analyses of starting cordierite mixture activated 5 to 240 minutes showed a mass decrease from 8 to12%. DT analyses showed the influence of mechanochemical activation of the starting components as increasing energy of the starting cordierite mixture, which resulted in moving the endothermic and exothermic effects to lower temperatures. The increasing of the temperatures of these effects was about 100°C, depending on activation time. IR analyses showed that relaxation time, that is laying-off time to the moment of sintering, do not influence changes of activated mixtures. Since the given results, it can be concluded that the activated sample has no changes to the moment of using for a certain purpose (sintering) for any time since activation.
PB  - Belgrade : Association of Metallurgical Engineers of Serbia (AMES)
C3  - Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia
T1  - Activation and relaxation time influence on cordierite ceramics
SP  - 61
EP  - 61
UR  - https://hdl.handle.net/21.15107/rcub_dais_14867
ER  - 

@conference{
author = "Đorđević, Nataša and Obradović, Nina and Sokić, Miroslav D. and Marković, Branislav R. and Patarić, Aleksandra and Petronijević, Nela",
year = "2019",
abstract = "Mechanochemical activation of 2MgO•2Al2O3•5SiO2, starting components of cordierite, was used in aim to decrease the sintering temperature. Cordierite is very attractive ceramic material due to its properties, excellent thermal shock resistance, low dielectric constants (~5) and low thermal expansions (20•10-7 ºC-1). Specific surface area of the activated components was detected by the BET method. TG and DTA methods have followed behaviors of the three-component system. To see the influence of relaxation time on the activated components, FT IR has analyzed the starting components as well as activated mixture after 24h and 24 months. TG analyses of starting cordierite mixture activated 5 to 240 minutes showed a mass decrease from 8 to12%. DT analyses showed the influence of mechanochemical activation of the starting components as increasing energy of the starting cordierite mixture, which resulted in moving the endothermic and exothermic effects to lower temperatures. The increasing of the temperatures of these effects was about 100°C, depending on activation time. IR analyses showed that relaxation time, that is laying-off time to the moment of sintering, do not influence changes of activated mixtures. Since the given results, it can be concluded that the activated sample has no changes to the moment of using for a certain purpose (sintering) for any time since activation.",
publisher = "Belgrade : Association of Metallurgical Engineers of Serbia (AMES)",
journal = "Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia",
title = "Activation and relaxation time influence on cordierite ceramics",
pages = "61-61",
url = "https://hdl.handle.net/21.15107/rcub_dais_14867"
}

Đorđević, N., Obradović, N., Sokić, M. D., Marković, B. R., Patarić, A.,& Petronijević, N.. (2019). Activation and relaxation time influence on cordierite ceramics. in Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia
Belgrade : Association of Metallurgical Engineers of Serbia (AMES)., 61-61.
https://hdl.handle.net/21.15107/rcub_dais_14867

Đorđević N, Obradović N, Sokić MD, Marković BR, Patarić A, Petronijević N. Activation and relaxation time influence on cordierite ceramics. in Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia. 2019;:61-61.
https://hdl.handle.net/21.15107/rcub_dais_14867 .

Đorđević, Nataša, Obradović, Nina, Sokić, Miroslav D., Marković, Branislav R., Patarić, Aleksandra, Petronijević, Nela, "Activation and relaxation time influence on cordierite ceramics" in Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia (2019):61-61,
https://hdl.handle.net/21.15107/rcub_dais_14867 .

TY  - CONF
AU  - Đorđević, Nataša
AU  - Obradović, Nina
AU  - Sokić, Miroslav D.
AU  - Marković, Branislav
AU  - Patarić, Aleksandra
AU  - Petronijević, Nela
PY  - 2019
UR  - https://dais.sanu.ac.rs/123456789/14866
AB  - The influence of Bi2O3 as a functional additive on the process of obtaining cordierite, 2MgO-2Al2O3-5SiO2 (MAS) was studied by sintering the MgO / Bi2O3 system (sintered at 820 °C and 1100 °C), Al2O3 / Bi2O3 and SiO2 / Bi2O3 (sintered at 1100 °C ), the composition being 80% oxide and 20% Bi2O3. The effects of sintering, composition, and morphology were followed by X-ray diffraction, scanning electron microscopy and EDS analysis. It has been found that, in addition to the liquid phase, Bi2O3 produces intermediate metastable compounds with MgO and Al2O3. The sintering of MAS ceramics with 10% Bi2O3 at 1000 °C, 1100 °C and 1200 °C was also performed. Binary systems MgO / Bi2O3 at 820 ºC and 1100 ºC, Al2O3 / Bi2O3 and SiO2 / Bi2O3 were sintered at 1100 ºC, as well as MgO, Al2O3, SiO2 / Bi2O3 at 1000 ºC, 1100 ºC and 1200 ºC to examine the reaction of the cordierite synthesis. The results show the formation of a liquid phase at 820 °C (melting temperature Bi2O3), as well as the formation of metastable compounds forming MgO and Al2O3 with Bi2O3 at 1100 °C and which diffuse through the liquid phase, thus enabling the mechanism of reaction in the multi-component system to be accelerated from two aspects. By the sintering of a three-component MAS system in the presence of Bi2O3, the existence of cordierite was established. The lowest temperature at which the tracer cordierite was observed (in hexagonal form - indialite) is 1100 °C, while in the sintered system at 1200 ºC the most frequent phase is indialite. This study found that the presence of Bi2O3 in basic cordierite mixture allows the sintering temperature to decrease by ~ 170 ºC relative to the temperature of the formation of cordierite ceramics from the mixture without the presence of functional additives.
PB  - Belgrade : Association of Metallurgical Engineers of Serbia (AMES)
C3  - Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia
T1  - Bi2O3 influence on electronic ceramics sintering process and final properties
SP  - 60
EP  - 60
UR  - https://hdl.handle.net/21.15107/rcub_dais_14866
ER  - 

@conference{
author = "Đorđević, Nataša and Obradović, Nina and Sokić, Miroslav D. and Marković, Branislav and Patarić, Aleksandra and Petronijević, Nela",
year = "2019",
abstract = "The influence of Bi2O3 as a functional additive on the process of obtaining cordierite, 2MgO-2Al2O3-5SiO2 (MAS) was studied by sintering the MgO / Bi2O3 system (sintered at 820 °C and 1100 °C), Al2O3 / Bi2O3 and SiO2 / Bi2O3 (sintered at 1100 °C ), the composition being 80% oxide and 20% Bi2O3. The effects of sintering, composition, and morphology were followed by X-ray diffraction, scanning electron microscopy and EDS analysis. It has been found that, in addition to the liquid phase, Bi2O3 produces intermediate metastable compounds with MgO and Al2O3. The sintering of MAS ceramics with 10% Bi2O3 at 1000 °C, 1100 °C and 1200 °C was also performed. Binary systems MgO / Bi2O3 at 820 ºC and 1100 ºC, Al2O3 / Bi2O3 and SiO2 / Bi2O3 were sintered at 1100 ºC, as well as MgO, Al2O3, SiO2 / Bi2O3 at 1000 ºC, 1100 ºC and 1200 ºC to examine the reaction of the cordierite synthesis. The results show the formation of a liquid phase at 820 °C (melting temperature Bi2O3), as well as the formation of metastable compounds forming MgO and Al2O3 with Bi2O3 at 1100 °C and which diffuse through the liquid phase, thus enabling the mechanism of reaction in the multi-component system to be accelerated from two aspects. By the sintering of a three-component MAS system in the presence of Bi2O3, the existence of cordierite was established. The lowest temperature at which the tracer cordierite was observed (in hexagonal form - indialite) is 1100 °C, while in the sintered system at 1200 ºC the most frequent phase is indialite. This study found that the presence of Bi2O3 in basic cordierite mixture allows the sintering temperature to decrease by ~ 170 ºC relative to the temperature of the formation of cordierite ceramics from the mixture without the presence of functional additives.",
publisher = "Belgrade : Association of Metallurgical Engineers of Serbia (AMES)",
journal = "Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia",
title = "Bi2O3 influence on electronic ceramics sintering process and final properties",
pages = "60-60",
url = "https://hdl.handle.net/21.15107/rcub_dais_14866"
}

Đorđević, N., Obradović, N., Sokić, M. D., Marković, B., Patarić, A.,& Petronijević, N.. (2019). Bi2O3 influence on electronic ceramics sintering process and final properties. in Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia
Belgrade : Association of Metallurgical Engineers of Serbia (AMES)., 60-60.
https://hdl.handle.net/21.15107/rcub_dais_14866

Đorđević N, Obradović N, Sokić MD, Marković B, Patarić A, Petronijević N. Bi2O3 influence on electronic ceramics sintering process and final properties. in Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia. 2019;:60-60.
https://hdl.handle.net/21.15107/rcub_dais_14866 .

Đorđević, Nataša, Obradović, Nina, Sokić, Miroslav D., Marković, Branislav, Patarić, Aleksandra, Petronijević, Nela, "Bi2O3 influence on electronic ceramics sintering process and final properties" in Book of Abstracts / Metallurgical & Materials Engineering Congress of South-East Europe (MME SEE 2019), June 5-7, 2019, Belgrade, Serbia (2019):60-60,
https://hdl.handle.net/21.15107/rcub_dais_14866 .

TY  - JOUR
AU  - Radosavljević-Mihajlović, Ana S.
AU  - Daković, Aleksandra S.
AU  - Kašić, Vladan
AU  - Mitić, Vojislav V.
AU  - Stojanović, Jovica N.
AU  - Sokić, Miroslav D.
AU  - Marković, Branislav R.
PY  - 2018
UR  - https://dais.sanu.ac.rs/123456789/5250
AB  - This paper presents mineralogical and crystallographic characterization of the zeolitic tuff from the Novakovic deposit, Republic of Bosnia and Herzegovina. The zeolitic tuff is of a whitish color composed of Ca-clinoptilolite and an amorphous phase (volcanic glass and amorphous SiO 2 ). The zeolitic tuff was analyzed by X-ray diffraction of the polycrystalline sample (XRPD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), and differential thermal and thermogravimetric (DTA/DTG) methods. According to the results obtained, it can be concluded that the studied zeolitic tuff is composed of Heu-type minerals. Based on the chemical analysis, thermal treatment and XRPD analysis it was determined that this is a mineral Ca-clinoptilolite. Thermal analysis in the temperature range from 300 up to 700°C showed that the examined zeolite minerals from the Novaković deposit are stable up to the temperature of 600°C. The crystal structure of Ca-clinoptilolite has been refined in the centrosymmetric space group C2/m (S.G. 12) with disordered distribution of Al and Si in the tetrahedral framework. The unit-cell parameters are as follows: a = 17.662 Å, b = 17.874 Å, c = 7.402 Å, β = 116.32° and V = 2122.73 Å 3 . The basic structural motif is represented by four channels. Three channels are composed of eight-membered rings, and one of ten-membered rings. The ten-membered (channel A) and one eight-membered channel (B) are parallel to the crystallographic axis c, and the other eight-membered channel is parallel to the a-axis. Ca-clinoptilolite comprises approximately 90 % of the studied zeolite tuff while the rest 10 % is the amorphous phase. The overall cation exchange capacity (CEC) amounts to 187 mmolM + / 100 g, and calcium represents the most abundant cation in the studied sample. The atomic ratios of Si/Al, Na + /(Na + +K + ), and Ca 2+ /(Ca 2+ +Mg 2+ ) are as follows: 4.36, 0.14, and 0.55, respectively. The zeolite tuff is both thermally and structurally stable and has applications in various areas of industry and agriculture. © 2018, Association of Chemists and Chemical Engineers of Serbia. All rights reserved.
PB  - Association of the Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Mineraloške i kristalografske osobine zeolitskog tufa heu-tipa lokaliteta novaković, Bosna i Hercegovina
SP  - 371
EP  - 382
VL  - 72
IS  - 6
DO  - 10.2298/HEMIND180725026R
UR  - https://hdl.handle.net/21.15107/rcub_dais_5250
ER  - 

@article{
author = "Radosavljević-Mihajlović, Ana S. and Daković, Aleksandra S. and Kašić, Vladan and Mitić, Vojislav V. and Stojanović, Jovica N. and Sokić, Miroslav D. and Marković, Branislav R.",
year = "2018",
abstract = "This paper presents mineralogical and crystallographic characterization of the zeolitic tuff from the Novakovic deposit, Republic of Bosnia and Herzegovina. The zeolitic tuff is of a whitish color composed of Ca-clinoptilolite and an amorphous phase (volcanic glass and amorphous SiO 2 ). The zeolitic tuff was analyzed by X-ray diffraction of the polycrystalline sample (XRPD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), and differential thermal and thermogravimetric (DTA/DTG) methods. According to the results obtained, it can be concluded that the studied zeolitic tuff is composed of Heu-type minerals. Based on the chemical analysis, thermal treatment and XRPD analysis it was determined that this is a mineral Ca-clinoptilolite. Thermal analysis in the temperature range from 300 up to 700°C showed that the examined zeolite minerals from the Novaković deposit are stable up to the temperature of 600°C. The crystal structure of Ca-clinoptilolite has been refined in the centrosymmetric space group C2/m (S.G. 12) with disordered distribution of Al and Si in the tetrahedral framework. The unit-cell parameters are as follows: a = 17.662 Å, b = 17.874 Å, c = 7.402 Å, β = 116.32° and V = 2122.73 Å 3 . The basic structural motif is represented by four channels. Three channels are composed of eight-membered rings, and one of ten-membered rings. The ten-membered (channel A) and one eight-membered channel (B) are parallel to the crystallographic axis c, and the other eight-membered channel is parallel to the a-axis. Ca-clinoptilolite comprises approximately 90 % of the studied zeolite tuff while the rest 10 % is the amorphous phase. The overall cation exchange capacity (CEC) amounts to 187 mmolM + / 100 g, and calcium represents the most abundant cation in the studied sample. The atomic ratios of Si/Al, Na + /(Na + +K + ), and Ca 2+ /(Ca 2+ +Mg 2+ ) are as follows: 4.36, 0.14, and 0.55, respectively. The zeolite tuff is both thermally and structurally stable and has applications in various areas of industry and agriculture. © 2018, Association of Chemists and Chemical Engineers of Serbia. All rights reserved.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Mineraloške i kristalografske osobine zeolitskog tufa heu-tipa lokaliteta novaković, Bosna i Hercegovina",
pages = "371-382",
volume = "72",
number = "6",
doi = "10.2298/HEMIND180725026R",
url = "https://hdl.handle.net/21.15107/rcub_dais_5250"
}

Radosavljević-Mihajlović, A. S., Daković, A. S., Kašić, V., Mitić, V. V., Stojanović, J. N., Sokić, M. D.,& Marković, B. R.. (2018). Mineraloške i kristalografske osobine zeolitskog tufa heu-tipa lokaliteta novaković, Bosna i Hercegovina. in Hemijska industrija
Association of the Chemical Engineers of Serbia., 72(6), 371-382.
https://doi.org/10.2298/HEMIND180725026R
https://hdl.handle.net/21.15107/rcub_dais_5250

Radosavljević-Mihajlović AS, Daković AS, Kašić V, Mitić VV, Stojanović JN, Sokić MD, Marković BR. Mineraloške i kristalografske osobine zeolitskog tufa heu-tipa lokaliteta novaković, Bosna i Hercegovina. in Hemijska industrija. 2018;72(6):371-382.
doi:10.2298/HEMIND180725026R
https://hdl.handle.net/21.15107/rcub_dais_5250 .

Radosavljević-Mihajlović, Ana S., Daković, Aleksandra S., Kašić, Vladan, Mitić, Vojislav V., Stojanović, Jovica N., Sokić, Miroslav D., Marković, Branislav R., "Mineraloške i kristalografske osobine zeolitskog tufa heu-tipa lokaliteta novaković, Bosna i Hercegovina" in Hemijska industrija, 72, no. 6 (2018):371-382,
https://doi.org/10.2298/HEMIND180725026R .,
https://hdl.handle.net/21.15107/rcub_dais_5250 .