TY  - JOUR
AU  - Šaponjić, A.
AU  - Ilić, S.
AU  - Barudzija, T.
AU  - Radosavljević-Mihajlović, Ana
AU  - Kokunešoski, Maja
AU  - Matović, Branko
PY  - 2023
UR  - https://ritnms.itnms.ac.rs/handle/123456789/652
AB  - In this paper, the effects of the addition of silicon nitride seeds on the phase composition, particle size, and shape of silicon nitride powders obtained by carbothermal reduction-nitridation were studied. Environmentally friendly natural raw material, diatomaceous earth, was used as a Si precursor. Three different carbon sources were used: activated carbon, carbonized sucrose, and carbon cryogel as reducing agents in the molar ratio C/SiO2 = 5. To obtain better-quality Si3N4 powder, the commercial α-Si3N4 powder was added into starting mixtures as seeds in four different quantities. The X-ray diffraction, specific surface area, infrared spectroscopy with Fourier transform, and scanning electron microscopy were employed to characterize the obtained powders. Sucrose as a carbon source enables a major reduction of SiO2 and the onset of β-Si3N4 crystallization at a lower temperature (1350 °C) as well as the complete absence of diatomaceous earth relics. It indicates that the carbothermal reduction-nitridation takes place faster in contrast to the other two carbon sources.
PB  - Springer
T2  - Journal of the Australian Ceramic Society
T1  - Seeded silicon nitride powders obtained by carbothermal reduction—nitridation of diatomite and various sources of carbon
DO  - 10.1007/s41779-023-00876-w
UR  - conv_985
ER  - 

@article{
author = "Šaponjić, A. and Ilić, S. and Barudzija, T. and Radosavljević-Mihajlović, Ana and Kokunešoski, Maja and Matović, Branko",
year = "2023",
abstract = "In this paper, the effects of the addition of silicon nitride seeds on the phase composition, particle size, and shape of silicon nitride powders obtained by carbothermal reduction-nitridation were studied. Environmentally friendly natural raw material, diatomaceous earth, was used as a Si precursor. Three different carbon sources were used: activated carbon, carbonized sucrose, and carbon cryogel as reducing agents in the molar ratio C/SiO2 = 5. To obtain better-quality Si3N4 powder, the commercial α-Si3N4 powder was added into starting mixtures as seeds in four different quantities. The X-ray diffraction, specific surface area, infrared spectroscopy with Fourier transform, and scanning electron microscopy were employed to characterize the obtained powders. Sucrose as a carbon source enables a major reduction of SiO2 and the onset of β-Si3N4 crystallization at a lower temperature (1350 °C) as well as the complete absence of diatomaceous earth relics. It indicates that the carbothermal reduction-nitridation takes place faster in contrast to the other two carbon sources.",
publisher = "Springer",
journal = "Journal of the Australian Ceramic Society",
title = "Seeded silicon nitride powders obtained by carbothermal reduction—nitridation of diatomite and various sources of carbon",
doi = "10.1007/s41779-023-00876-w",
url = "conv_985"
}

Šaponjić, A., Ilić, S., Barudzija, T., Radosavljević-Mihajlović, A., Kokunešoski, M.,& Matović, B.. (2023). Seeded silicon nitride powders obtained by carbothermal reduction—nitridation of diatomite and various sources of carbon. in Journal of the Australian Ceramic Society
Springer..
https://doi.org/10.1007/s41779-023-00876-w
conv_985

Šaponjić A, Ilić S, Barudzija T, Radosavljević-Mihajlović A, Kokunešoski M, Matović B. Seeded silicon nitride powders obtained by carbothermal reduction—nitridation of diatomite and various sources of carbon. in Journal of the Australian Ceramic Society. 2023;.
doi:10.1007/s41779-023-00876-w
conv_985 .

Šaponjić, A., Ilić, S., Barudzija, T., Radosavljević-Mihajlović, Ana, Kokunešoski, Maja, Matović, Branko, "Seeded silicon nitride powders obtained by carbothermal reduction—nitridation of diatomite and various sources of carbon" in Journal of the Australian Ceramic Society (2023),
https://doi.org/10.1007/s41779-023-00876-w .,
conv_985 .

TY  - JOUR
AU  - Isek, Josip
AU  - Kaluđerović, Lazar M.
AU  - Vuković, Nikola
AU  - Milošević, Maja
AU  - Vukasinović, Ivana
AU  - Tomić, Zorica
PY  - 2020
UR  - https://ritnms.itnms.ac.rs/handle/123456789/547
AB  - Two samples collected from the phosphogypsum deposits of the chemical products industry Elixir Prahovo (Serbia) were subjected to a recrystallization experiment performed over several repeated cycles. In these tests, phosphogypsum was separated into recrystallized (purified) gypsum, insoluble residue and supernatant. Both raw phosphogypsum and recrystallized gypsum were examined using inductively coupled plasma optical emission spectrometry, X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry. The activity concentrations of (238)u, (235)u, Ra-226, Pb-210,Th- 232 and 40 K were investigated using gamma-ray spectrometry. Based on the activity concentration results, a number of radiometric parameters were calculated for the original and recrystallized phosphogypsum (i.e. radium equivalent activity, y indices for construction materials, a index and external and internal hazard indices). Raw phosphogypsum samples showed greater mean activity concentration levels of U-238 and Ra-226 than the international recommended limits, while the recrystallized gypsum demonstrated notably lower activity concentrations for these two isotopes. The activity concentration of Ra-226 in recrystallized gypsum is similar to 6 times lower than in raw phosphogypsum. Therefore, recrystallized gypsum does not present a radiation hazard when used as a building material, while raw phosphogypsum meets the requirements only for road construction materials.
PB  - Mineralogical Soc, Twickenham
T2  - Clay Minerals
T1  - Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering
EP  - 70
IS  - 1
SP  - 63
VL  - 55
DO  - 10.1180/clm.2020.11
UR  - conv_883
ER  - 

@article{
author = "Isek, Josip and Kaluđerović, Lazar M. and Vuković, Nikola and Milošević, Maja and Vukasinović, Ivana and Tomić, Zorica",
year = "2020",
abstract = "Two samples collected from the phosphogypsum deposits of the chemical products industry Elixir Prahovo (Serbia) were subjected to a recrystallization experiment performed over several repeated cycles. In these tests, phosphogypsum was separated into recrystallized (purified) gypsum, insoluble residue and supernatant. Both raw phosphogypsum and recrystallized gypsum were examined using inductively coupled plasma optical emission spectrometry, X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry. The activity concentrations of (238)u, (235)u, Ra-226, Pb-210,Th- 232 and 40 K were investigated using gamma-ray spectrometry. Based on the activity concentration results, a number of radiometric parameters were calculated for the original and recrystallized phosphogypsum (i.e. radium equivalent activity, y indices for construction materials, a index and external and internal hazard indices). Raw phosphogypsum samples showed greater mean activity concentration levels of U-238 and Ra-226 than the international recommended limits, while the recrystallized gypsum demonstrated notably lower activity concentrations for these two isotopes. The activity concentration of Ra-226 in recrystallized gypsum is similar to 6 times lower than in raw phosphogypsum. Therefore, recrystallized gypsum does not present a radiation hazard when used as a building material, while raw phosphogypsum meets the requirements only for road construction materials.",
publisher = "Mineralogical Soc, Twickenham",
journal = "Clay Minerals",
title = "Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering",
pages = "70-63",
number = "1",
volume = "55",
doi = "10.1180/clm.2020.11",
url = "conv_883"
}

Isek, J., Kaluđerović, L. M., Vuković, N., Milošević, M., Vukasinović, I.,& Tomić, Z.. (2020). Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering. in Clay Minerals
Mineralogical Soc, Twickenham., 55(1), 63-70.
https://doi.org/10.1180/clm.2020.11
conv_883

Isek J, Kaluđerović LM, Vuković N, Milošević M, Vukasinović I, Tomić Z. Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering. in Clay Minerals. 2020;55(1):63-70.
doi:10.1180/clm.2020.11
conv_883 .

Isek, Josip, Kaluđerović, Lazar M., Vuković, Nikola, Milošević, Maja, Vukasinović, Ivana, Tomić, Zorica, "Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering" in Clay Minerals, 55, no. 1 (2020):63-70,
https://doi.org/10.1180/clm.2020.11 .,
conv_883 .

TY  - JOUR
AU  - Kaluđerović, Lazar M.
AU  - Isek, Josip
AU  - Vuković, Nikola
AU  - Milošević, Maja
PY  - 2019
UR  - https://ritnms.itnms.ac.rs/handle/123456789/491
AB  - In this study, the chemical and phase composition of two samples of phosphogypsum from the waste dumps of the Industry of Chemical Products "Elixir - Prahovo" (Serbia) were examined, as well as the possibility of recrystallization of gypsum from an aqueous suspension of phosphogypsum. 'the negative effect of higher temperatures on the solubility of calcium sulfate (13.08 mmol/dm(3) at 95 degrees C vs. 15.43 mmol/dm(3) at 40 degrees C) was utilized. In several repeated cycles, calcium sulfate component was progressively dissolved in water at room temperature and then precipitated at 100 degrees C, using the same liquid phase throughout the experiment. Therefore, phosphogypsum was separated into recrystallized (purified) gypsum, insoluble residue and supernatant, and the mass balance for the experiment was calculated. Elemental, XRD and SEM-EDS analyses were performed on raw phosphogypsum, purified gypsum and insoluble residue. The whiteness of raw phosphogypsum and purified gypsum were determined and compared. The main objective of the study was to investigate the nature of insoluble impurities, in order to define and optimize the methods for their removal during a potential industrial processing of phosphogypsum.
PB  - Polish Mineral Eng Soc, Krakow
T2  - Inzynieria Mineralna-Journal of the Polish Mineral Engineering Society
T1  - Characterisation of Purified Gypsum and Insoluble Impurities Obtained from Phosphogypsum Waste
EP  - 78
IS  - 1
SP  - 73
DO  - 10.29227/IM-2019-01-13
UR  - conv_857
ER  - 

@article{
author = "Kaluđerović, Lazar M. and Isek, Josip and Vuković, Nikola and Milošević, Maja",
year = "2019",
abstract = "In this study, the chemical and phase composition of two samples of phosphogypsum from the waste dumps of the Industry of Chemical Products "Elixir - Prahovo" (Serbia) were examined, as well as the possibility of recrystallization of gypsum from an aqueous suspension of phosphogypsum. 'the negative effect of higher temperatures on the solubility of calcium sulfate (13.08 mmol/dm(3) at 95 degrees C vs. 15.43 mmol/dm(3) at 40 degrees C) was utilized. In several repeated cycles, calcium sulfate component was progressively dissolved in water at room temperature and then precipitated at 100 degrees C, using the same liquid phase throughout the experiment. Therefore, phosphogypsum was separated into recrystallized (purified) gypsum, insoluble residue and supernatant, and the mass balance for the experiment was calculated. Elemental, XRD and SEM-EDS analyses were performed on raw phosphogypsum, purified gypsum and insoluble residue. The whiteness of raw phosphogypsum and purified gypsum were determined and compared. The main objective of the study was to investigate the nature of insoluble impurities, in order to define and optimize the methods for their removal during a potential industrial processing of phosphogypsum.",
publisher = "Polish Mineral Eng Soc, Krakow",
journal = "Inzynieria Mineralna-Journal of the Polish Mineral Engineering Society",
title = "Characterisation of Purified Gypsum and Insoluble Impurities Obtained from Phosphogypsum Waste",
pages = "78-73",
number = "1",
doi = "10.29227/IM-2019-01-13",
url = "conv_857"
}

Kaluđerović, L. M., Isek, J., Vuković, N.,& Milošević, M.. (2019). Characterisation of Purified Gypsum and Insoluble Impurities Obtained from Phosphogypsum Waste. in Inzynieria Mineralna-Journal of the Polish Mineral Engineering Society
Polish Mineral Eng Soc, Krakow.(1), 73-78.
https://doi.org/10.29227/IM-2019-01-13
conv_857

Kaluđerović LM, Isek J, Vuković N, Milošević M. Characterisation of Purified Gypsum and Insoluble Impurities Obtained from Phosphogypsum Waste. in Inzynieria Mineralna-Journal of the Polish Mineral Engineering Society. 2019;(1):73-78.
doi:10.29227/IM-2019-01-13
conv_857 .

Kaluđerović, Lazar M., Isek, Josip, Vuković, Nikola, Milošević, Maja, "Characterisation of Purified Gypsum and Insoluble Impurities Obtained from Phosphogypsum Waste" in Inzynieria Mineralna-Journal of the Polish Mineral Engineering Society, no. 1 (2019):73-78,
https://doi.org/10.29227/IM-2019-01-13 .,
conv_857 .