TY  - CONF
AU  - Oljača, Đurđa
AU  - Milovanović, Biljana
AU  - Pavlović, Stefan
AU  - Smiljanić, Radenko
AU  - Obrenović, Zoran
AU  - Filipović, Radislav
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3771
AB  - The presence of Zn compounds in alumina reduces the current efficiency during electrolysis and quality of obtained metal. The known methods for Zn compounds removal that involves the use of different chemical agents (e.g. sulphide) are uneconomical and not environmentally friendly. In this research, aluminium-hydroxide with specific structural properties (AHSSP) was used as a crystallization agent during purification of Bayer liquor. The specific structural properties of the used aluminium-hydroxide are related with a small particle size (<8μm), small specific surface area (≈3 m2/g), and large pore diameter (≈1μm). Mechanism of Zn removal is based on crystallization phenomenon of aluminium-hydroxide from Bayer liquor where the AHSSP presents crystallization agent (seed). The crystallization process is conducted to a certain Na2O/Al2O3 ratio, which corresponds to a satisfactory aluminium concentration in Bayer liquor. The crystallization process was conducted in laboratory crystallization vessels (2 dm3) equipped with a heater and stirrer. The crystallization temperature was 50±1°C and the concentration of aluminium-hydroxide as crystallization agent (seed) was 15, 20 and 30g/l. The concentration of Al, Na, and Zn in Bayer liquor and solid crystallization product (aluminium hydroxide as seed and aluminium hydroxide from Bayer liquor) was analysed by using ICP-OES (Specto Genesis) and AAS (Shimadzu AA7000). The particle size of the obtained solid crystallization product was analysed by Cilas 1090, laser particle size analyser. The specific surface area was determined by using Gemini VII, whereas the pore structure was analysed by using Mercury intrusion porosimetry (Carlo Erba Porosimeter 2000). The obtained results show that the per cent of removed Zn compounds was above 80 for 2h, whereas Al concentration decreased slightly less than 20% for the same time. Structural analysis is shown, that particle size and pore diameter were increased, whereas the specific surface area was decreased. For this reason, the possibility of using the aluminium-hydroxide as a product of this process, without structural modification, is maximally two times. Keywords: Zn-compounds, crystallization, alumina, and structural properties.
PB  - Association of Technology Engineers of Republic of Srpska
C3  - Proceedings - XII Conference of Chemists, Technologists and Environmentalists of Republic of Srpska
T1  - Zinc removal from Bayer liquor by using aluminium hydroxide with specific structural properties as crystallization agent
SP  - 155
EP  - 158
UR  - https://hdl.handle.net/21.15107/rcub_cer_3771
ER  - 

@conference{
author = "Oljača, Đurđa and Milovanović, Biljana and Pavlović, Stefan and Smiljanić, Radenko and Obrenović, Zoran and Filipović, Radislav",
year = "2018",
abstract = "The presence of Zn compounds in alumina reduces the current efficiency during electrolysis and quality of obtained metal. The known methods for Zn compounds removal that involves the use of different chemical agents (e.g. sulphide) are uneconomical and not environmentally friendly. In this research, aluminium-hydroxide with specific structural properties (AHSSP) was used as a crystallization agent during purification of Bayer liquor. The specific structural properties of the used aluminium-hydroxide are related with a small particle size (<8μm), small specific surface area (≈3 m2/g), and large pore diameter (≈1μm). Mechanism of Zn removal is based on crystallization phenomenon of aluminium-hydroxide from Bayer liquor where the AHSSP presents crystallization agent (seed). The crystallization process is conducted to a certain Na2O/Al2O3 ratio, which corresponds to a satisfactory aluminium concentration in Bayer liquor. The crystallization process was conducted in laboratory crystallization vessels (2 dm3) equipped with a heater and stirrer. The crystallization temperature was 50±1°C and the concentration of aluminium-hydroxide as crystallization agent (seed) was 15, 20 and 30g/l. The concentration of Al, Na, and Zn in Bayer liquor and solid crystallization product (aluminium hydroxide as seed and aluminium hydroxide from Bayer liquor) was analysed by using ICP-OES (Specto Genesis) and AAS (Shimadzu AA7000). The particle size of the obtained solid crystallization product was analysed by Cilas 1090, laser particle size analyser. The specific surface area was determined by using Gemini VII, whereas the pore structure was analysed by using Mercury intrusion porosimetry (Carlo Erba Porosimeter 2000). The obtained results show that the per cent of removed Zn compounds was above 80 for 2h, whereas Al concentration decreased slightly less than 20% for the same time. Structural analysis is shown, that particle size and pore diameter were increased, whereas the specific surface area was decreased. For this reason, the possibility of using the aluminium-hydroxide as a product of this process, without structural modification, is maximally two times. Keywords: Zn-compounds, crystallization, alumina, and structural properties.",
publisher = "Association of Technology Engineers of Republic of Srpska",
journal = "Proceedings - XII Conference of Chemists, Technologists and Environmentalists of Republic of Srpska",
title = "Zinc removal from Bayer liquor by using aluminium hydroxide with specific structural properties as crystallization agent",
pages = "155-158",
url = "https://hdl.handle.net/21.15107/rcub_cer_3771"
}

Oljača, Đ., Milovanović, B., Pavlović, S., Smiljanić, R., Obrenović, Z.,& Filipović, R.. (2018). Zinc removal from Bayer liquor by using aluminium hydroxide with specific structural properties as crystallization agent. in Proceedings - XII Conference of Chemists, Technologists and Environmentalists of Republic of Srpska
Association of Technology Engineers of Republic of Srpska., 155-158.
https://hdl.handle.net/21.15107/rcub_cer_3771

Oljača Đ, Milovanović B, Pavlović S, Smiljanić R, Obrenović Z, Filipović R. Zinc removal from Bayer liquor by using aluminium hydroxide with specific structural properties as crystallization agent. in Proceedings - XII Conference of Chemists, Technologists and Environmentalists of Republic of Srpska. 2018;:155-158.
https://hdl.handle.net/21.15107/rcub_cer_3771 .

Oljača, Đurđa, Milovanović, Biljana, Pavlović, Stefan, Smiljanić, Radenko, Obrenović, Zoran, Filipović, Radislav, "Zinc removal from Bayer liquor by using aluminium hydroxide with specific structural properties as crystallization agent" in Proceedings - XII Conference of Chemists, Technologists and Environmentalists of Republic of Srpska (2018):155-158,
https://hdl.handle.net/21.15107/rcub_cer_3771 .

TY  - JOUR
AU  - Janković, Mladen
AU  - Obrenović, Zoran
AU  - Filipović, Radislav
AU  - Ostojić, Željko
AU  - Došić, Aleksandar
AU  - Milovanović, Biljana
AU  - Tomašević, Dragana
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3777
AB  - For more than three decades 4A zeolite has been an irreplaceable ingredient of powder
detergents, but there is still striving to it’s improvement in order to meet the ever more stringent
market and environmental demands.Alumina d.o.o., as one of the world-renowned producers of
this zeolite, tends to meet these requirements, and one of the latest examples is the work on the
production of zeolite 4A with increased adsorption of surface active substances, and the testing of
parameters for the synthesis of such a zeolite as well as its characterization is the subject of this
paper. The zeolite synthesis were performed to examine the effect of the Na2O concentration in
the reaction system, as well as the crystallization time on thecharacteristics of detergent zeolite,
namely:the adsorption of dibutylphthalate (DBP), the mean particle diameter, and the ion
exchange capacity. The additional characterization of the samples was performed by XRD and
FTIR instrumental methods.
It’s shown that the conditions examined have a significant effect on the characteristics of the
synthesized powders. In general, at all crystallization times, adsorption of DBP, as well as the
mean diameter, increases with the increase in Na2O concentration, while the ion exchange
capacity decreases,and it is very important to find the right conditions in which all the parameters
will be satisfactory.The influence of the crystallization time is not significantly pronounced when
adsorption is concerned, but it is on the other characteristics of zeolite.XRD diffractograms and
FT-IR spectroscopy showed the effect of reaction conditions on the crystallinity of the synthesized
powders, and the relationship between the crystallinity and other characteristics of 4A zeolite.
AB  - Zeolit 4A sada već više od tri decenije nezamenljiv je sastojak praškastih deterdženata, ali se i dalje teži njegovom usavršavanju kako bi se što uspešnije ispunili sve strožiji tržišni i ekološki zahtevi. Kompanija Alumina d.o.o. kao jedan od svetski priznatih proizvođača ovog zeolita teži ispunjavanju tih zahteva. Predmet ovog rada je upravo ispitivanje parametara za sintezu takvog zeolita kao i njegova karakterizacija. Sinteze zeolita izvođene su tako da se ispita uticaj koncentracije Na2O u reakcionom sistemu, kao i vremena kristalizacije na karakteristike deterdžentskog zeolita, i to adsorpciju dibutilftalata (DBP), srednji prečnik čestice (Ds50) i jonoizmenjivački kappacitet (JIK).Dodatna karakterizacija uzoraka izvršena je XRD i FTIR instrumentalnim metodama. Pokazalo se da ispitivani uslovi imaju značajan uticaj na karakteristike sintetisanih prahova. Generalno, pri svim vremenima kristalizacije, adsorpcija DBP raste sa porastom koncentracije Na2O, kao i srednji prečnik, dok JIK opada, te je jako bitno pronaći uslove u kojima će svi parametri biti zadovoljavajući. Uticaj vremena nije značajno izražen kada je adsorpcija u pitanju, ali jeste na ostale karakteristike zeolita. XRD difraktogramii FT-IR spektroskopija pokazali su uticaj reakcionih uslova na kristaliničnost, te vezu između kristaliničnosti i drugih karakteristika 4A zeolita.
PB  - Inženjersko društvo za koroziju
T2  - Zaštita materijala
T1  - Influence of process parameters on properties of the 4a zeolite with X-ray and FT-IR instrumental methods characterization
T1  - Uticaj procesnih parametara na osobine 4a zeolita uz karakterizaciju X-ray i FT-IR instrumentalnim metodama
VL  - 59
IS  - 3
SP  - 401
EP  - 409
DO  - 10.5937/ZasMat1803401J
ER  - 

@article{
author = "Janković, Mladen and Obrenović, Zoran and Filipović, Radislav and Ostojić, Željko and Došić, Aleksandar and Milovanović, Biljana and Tomašević, Dragana",
year = "2018",
abstract = "For more than three decades 4A zeolite has been an irreplaceable ingredient of powder
detergents, but there is still striving to it’s improvement in order to meet the ever more stringent
market and environmental demands.Alumina d.o.o., as one of the world-renowned producers of
this zeolite, tends to meet these requirements, and one of the latest examples is the work on the
production of zeolite 4A with increased adsorption of surface active substances, and the testing of
parameters for the synthesis of such a zeolite as well as its characterization is the subject of this
paper. The zeolite synthesis were performed to examine the effect of the Na2O concentration in
the reaction system, as well as the crystallization time on thecharacteristics of detergent zeolite,
namely:the adsorption of dibutylphthalate (DBP), the mean particle diameter, and the ion
exchange capacity. The additional characterization of the samples was performed by XRD and
FTIR instrumental methods.
It’s shown that the conditions examined have a significant effect on the characteristics of the
synthesized powders. In general, at all crystallization times, adsorption of DBP, as well as the
mean diameter, increases with the increase in Na2O concentration, while the ion exchange
capacity decreases,and it is very important to find the right conditions in which all the parameters
will be satisfactory.The influence of the crystallization time is not significantly pronounced when
adsorption is concerned, but it is on the other characteristics of zeolite.XRD diffractograms and
FT-IR spectroscopy showed the effect of reaction conditions on the crystallinity of the synthesized
powders, and the relationship between the crystallinity and other characteristics of 4A zeolite., Zeolit 4A sada već više od tri decenije nezamenljiv je sastojak praškastih deterdženata, ali se i dalje teži njegovom usavršavanju kako bi se što uspešnije ispunili sve strožiji tržišni i ekološki zahtevi. Kompanija Alumina d.o.o. kao jedan od svetski priznatih proizvođača ovog zeolita teži ispunjavanju tih zahteva. Predmet ovog rada je upravo ispitivanje parametara za sintezu takvog zeolita kao i njegova karakterizacija. Sinteze zeolita izvođene su tako da se ispita uticaj koncentracije Na2O u reakcionom sistemu, kao i vremena kristalizacije na karakteristike deterdžentskog zeolita, i to adsorpciju dibutilftalata (DBP), srednji prečnik čestice (Ds50) i jonoizmenjivački kappacitet (JIK).Dodatna karakterizacija uzoraka izvršena je XRD i FTIR instrumentalnim metodama. Pokazalo se da ispitivani uslovi imaju značajan uticaj na karakteristike sintetisanih prahova. Generalno, pri svim vremenima kristalizacije, adsorpcija DBP raste sa porastom koncentracije Na2O, kao i srednji prečnik, dok JIK opada, te je jako bitno pronaći uslove u kojima će svi parametri biti zadovoljavajući. Uticaj vremena nije značajno izražen kada je adsorpcija u pitanju, ali jeste na ostale karakteristike zeolita. XRD difraktogramii FT-IR spektroskopija pokazali su uticaj reakcionih uslova na kristaliničnost, te vezu između kristaliničnosti i drugih karakteristika 4A zeolita.",
publisher = "Inženjersko društvo za koroziju",
journal = "Zaštita materijala",
title = "Influence of process parameters on properties of the 4a zeolite with X-ray and FT-IR instrumental methods characterization, Uticaj procesnih parametara na osobine 4a zeolita uz karakterizaciju X-ray i FT-IR instrumentalnim metodama",
volume = "59",
number = "3",
pages = "401-409",
doi = "10.5937/ZasMat1803401J"
}

Janković, M., Obrenović, Z., Filipović, R., Ostojić, Ž., Došić, A., Milovanović, B.,& Tomašević, D.. (2018). Influence of process parameters on properties of the 4a zeolite with X-ray and FT-IR instrumental methods characterization. in Zaštita materijala
Inženjersko društvo za koroziju., 59(3), 401-409.
https://doi.org/10.5937/ZasMat1803401J

Janković M, Obrenović Z, Filipović R, Ostojić Ž, Došić A, Milovanović B, Tomašević D. Influence of process parameters on properties of the 4a zeolite with X-ray and FT-IR instrumental methods characterization. in Zaštita materijala. 2018;59(3):401-409.
doi:10.5937/ZasMat1803401J .

Janković, Mladen, Obrenović, Zoran, Filipović, Radislav, Ostojić, Željko, Došić, Aleksandar, Milovanović, Biljana, Tomašević, Dragana, "Influence of process parameters on properties of the 4a zeolite with X-ray and FT-IR instrumental methods characterization" in Zaštita materijala, 59, no. 3 (2018):401-409,
https://doi.org/10.5937/ZasMat1803401J . .

TY  - CONF
AU  - Perušić, Mitar
AU  - Pejović, Branko
AU  - Pavlović, Stefan
AU  - Kešelj, Dragana
AU  - Filipović, Radislav
PY  - 2016
UR  - http://savjetovanjetfbl.conforganiser.com/presentation/paperpresentation/406/4628
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4000
AB  - The paper is based on the fact that the internal energy, enthalpy and enthropy as most important thermodynamic state functions, can not be determined in absolut terms without reference state slections. It is demonstrated that to determination must be approached very cautiously. The reason for this is possibility of errors that are not permissible. The beginning conditions of measurement can be adopted. It is also necessary to pay attention to the beginning the measurement of the adopted reference value. For a case to be simultaneous determination of multiple state functions, it should take to account the beginning of the measurement of each of these functions, since this start may different. In this way the calculated state function vares, depending on refenece state is adopted. At the end, in one convenient example, in the case internal energy and enthalpy, as a characteristic state function, is pointed to possiility errors, which could occur if there is no detailed analysis of adopted reference of „zero“ state.
AB  - U radu je, polazeći od činjenice da se unutrašnja energija, entalpija i entropija kao najvažnije termodinamičke veličine stanja, ne mogu odrediti u apsolutnom iznosu bez izbora referentnog stanja, pokazano da je pri ovom određivanju potrebno pristupiti veoma obazrivo. Razlog za ovo je mogućnost grešaka koje nisu dopustive. Pri ovome usvojeni početak merenja može u opštem slučaju biti različit. Neophodno je takođe obratiti pažnju na definisanost određene veličine stanja za usvojenu referentnu vrednost. Za slučaj da se vrši istovremeno određivanje više veličina stanja, treba voditi računa o početku merenja svake od ovih veličina, s obzirom da ovaj početak može biti različit. Na ovaj način izračunata veličina stanja zavisi od toga koje referentno stanje je usvojeno. Na kraju rada, koristeći praktičan računski primeru, za slučaj unutrašnje energije i entalpije, kao karakterističnih veličina stanja, ukazano je na mogućnost greške, koja se može javiti ukoliko se ne izvrši detaljna analiza izbora referentnog, odnosno „nultog“ stanja.
PB  - Banja Luka, Republic of Srpska, Bosnia and Herzegovina : 	Tehnološki fakultet Univerziteta u Banjoj Luci
C3  - XI Conference of Chemists, Technologists and Environmentalists of Republic of Srpska, Teslić
T1  - Analytical error during selection of reference state in thermodynamic of ideal gas
T1  - Analitička greška kod izbora referentnog stanja u termodinamici idealnog gasa
UR  - https://hdl.handle.net/21.15107/rcub_cer_4000
ER  - 

@conference{
author = "Perušić, Mitar and Pejović, Branko and Pavlović, Stefan and Kešelj, Dragana and Filipović, Radislav",
year = "2016",
abstract = "The paper is based on the fact that the internal energy, enthalpy and enthropy as most important thermodynamic state functions, can not be determined in absolut terms without reference state slections. It is demonstrated that to determination must be approached very cautiously. The reason for this is possibility of errors that are not permissible. The beginning conditions of measurement can be adopted. It is also necessary to pay attention to the beginning the measurement of the adopted reference value. For a case to be simultaneous determination of multiple state functions, it should take to account the beginning of the measurement of each of these functions, since this start may different. In this way the calculated state function vares, depending on refenece state is adopted. At the end, in one convenient example, in the case internal energy and enthalpy, as a characteristic state function, is pointed to possiility errors, which could occur if there is no detailed analysis of adopted reference of „zero“ state., U radu je, polazeći od činjenice da se unutrašnja energija, entalpija i entropija kao najvažnije termodinamičke veličine stanja, ne mogu odrediti u apsolutnom iznosu bez izbora referentnog stanja, pokazano da je pri ovom određivanju potrebno pristupiti veoma obazrivo. Razlog za ovo je mogućnost grešaka koje nisu dopustive. Pri ovome usvojeni početak merenja može u opštem slučaju biti različit. Neophodno je takođe obratiti pažnju na definisanost određene veličine stanja za usvojenu referentnu vrednost. Za slučaj da se vrši istovremeno određivanje više veličina stanja, treba voditi računa o početku merenja svake od ovih veličina, s obzirom da ovaj početak može biti različit. Na ovaj način izračunata veličina stanja zavisi od toga koje referentno stanje je usvojeno. Na kraju rada, koristeći praktičan računski primeru, za slučaj unutrašnje energije i entalpije, kao karakterističnih veličina stanja, ukazano je na mogućnost greške, koja se može javiti ukoliko se ne izvrši detaljna analiza izbora referentnog, odnosno „nultog“ stanja.",
publisher = "Banja Luka, Republic of Srpska, Bosnia and Herzegovina : 	Tehnološki fakultet Univerziteta u Banjoj Luci",
journal = "XI Conference of Chemists, Technologists and Environmentalists of Republic of Srpska, Teslić",
title = "Analytical error during selection of reference state in thermodynamic of ideal gas, Analitička greška kod izbora referentnog stanja u termodinamici idealnog gasa",
url = "https://hdl.handle.net/21.15107/rcub_cer_4000"
}

Perušić, M., Pejović, B., Pavlović, S., Kešelj, D.,& Filipović, R.. (2016). Analytical error during selection of reference state in thermodynamic of ideal gas. in XI Conference of Chemists, Technologists and Environmentalists of Republic of Srpska, Teslić
Banja Luka, Republic of Srpska, Bosnia and Herzegovina : 	Tehnološki fakultet Univerziteta u Banjoj Luci..
https://hdl.handle.net/21.15107/rcub_cer_4000

Perušić M, Pejović B, Pavlović S, Kešelj D, Filipović R. Analytical error during selection of reference state in thermodynamic of ideal gas. in XI Conference of Chemists, Technologists and Environmentalists of Republic of Srpska, Teslić. 2016;.
https://hdl.handle.net/21.15107/rcub_cer_4000 .

Perušić, Mitar, Pejović, Branko, Pavlović, Stefan, Kešelj, Dragana, Filipović, Radislav, "Analytical error during selection of reference state in thermodynamic of ideal gas" in XI Conference of Chemists, Technologists and Environmentalists of Republic of Srpska, Teslić (2016),
https://hdl.handle.net/21.15107/rcub_cer_4000 .