JSCS Vol 72, No. 8-9
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J. Serb.
Chem. Soc. 72 (8–9) 737–746 (2007)
UDC 539.219.1+535.42+54–77:547.458.68,
JSCS–3607, doi: 10.2298/JSC0709737N; Original scientific paper
A molecular inclusion complex of atenolol with 2-hydroxypropyl-b-cyclodextrin; the production and characterization
thereof
VESNA NIKOLIC, LJUBISA NIKOLIC, MIHAJLO STANKOVIC, AGNES KAPOR*, MIRJANA
POPSAVIN** and DRAGAN
CVETKOVIC
Faculty of Technology, Bulevar oslobodjenja 124, 16000
*Faculty of Science, Department of Physics, Trg Dositeja Obradovica 4,
21000
**Faculty of Science, Department
of Chemistry, Trg Dositeja
Obradovica 3, 21000
(Received
The molecular inclusion complex of atenolol with
2-hydroxypropyl-b-cyclodextrin was synthesized using the
coprecipitation method. The complex obtained was characterized by FT-IR, 1H‑NMR,
13C-NMR spectroscopy, as well as by DSC and X-ray diffraction analysis. The DSC analysis confirmed the existence
of the complex with the endothermic atenolol melting peak at about
155 ºC disappearing. The X-ray diffraction patterns of the complex and
2-hydroxypropyl-b-cyclodextrin were very similar, thus confirming the
complete inclusion of the atenolol molecule within
the cavity of the 2-hydroxypropyl-b-cyclodextrin. The peaks
originating from atenolol were
completely absent in the diffractogrAM of the complex. 1H-NMR and 13C-NMR
spectra showed certain changes in the chemical shifts of protons and C atoms
from atenolol and 2-hydroxypropyl-b-cyclodextrin, indicating that a complex had been formed and also which
protons participated in the hydrogen bonds which formed the complex. The
atenolol solubility in water was improved (254 mg complex cm-3,
i.e.,
37.5 mg atenolol cm-3), and in pH 3 HCl solution
(251 mg complex cm-3, i.e., 37 mg atenolol cm-3) when compared to pure atenolol, and even when
compared to the atenolol complex with b-cyclodextrin. The increased solubility ensures
greater bioavailability of the active component and, due to the low solubility,
significantly corrects for the lack of the basic active substance and,
simultaneously, increases its overall therapeutic effect, combined with reduced
side effects.
Keywords: atenolol, 2-hydroxypropyl-b-cyclodextrin, inclusion complex, FT-IR, DSC, NMR,
X-ray.
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J. Serb.
Chem. Soc. 72 (8–9) 747–755 (2007)
UDC 547.541+547.53.024+547.86:615,
JSCS–3608, doi: 10.2298/JSC0709747A; Original scientific paper
6-[2-(4-Arylpiperazin-1-yl)ethyl]-4-halo-1,3-dihydro-2H-benzimidazole-2-thiones: synthesis and
pharmacological evaluation
DEANA ANDRIC, GORDANA TOVILOVIC,
GORAN ROGLIC, VUKIC SOSKIC**,***, MIRKO TOMIC* and SLADJANA
KOSTIC–RAJACIC**
Faculty of Chemistry,
*Department of Biochemistry, Institute for Biological Research, Bulevar
Despota Stefana 142, 11060
**Center for Chemistry, Institute for Chemistry, Technology and
Metallurgy, Njegoseva 12, 11000
***Proteosys AG, Carl–Zeiss–Str. 51, 55129 Mainz, Germany
(Received
Eight new compounds with halogen atom
introduced into the benzimidazole-2-thione dopAMinergic pharmacophore of
5-[2-(4-arylpiperazin-1-yl)ethyl]-1,3-dihydro-2H-benzimidazole-2-thiones
with the arylpiperazine part of the molecule being selected according to known
structure–affinity requirements, have been synthesized. All the new compounds
were evaluated for the in vitro
binding affinity at the dopamine (DA) D1 and D2 and serotonin
5-HT1A receptors by the competitive radioassays, performed on
synaptosomal membranes prepared from fresh bovine caudate nuclei and
hippocAMpi. All the new compounds were strong competitors for the binding of the radioligands to the D2 and
5-HT1A receptors, with the most active of them having 34 and 170 time higher affinity than
non-halogenated congeners in the D2 DA receptor radioassays
(compounds 9.1b and 9.2b, respectively). Divergently, these
compounds were without significant affinities for the D1 DA
receptors.
Keywords: arylpiperazines, benzimidazole-2-thiones, dopAMine receptors, serotonin
receptors.
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J. Serb.
Chem. Soc. 72 (8–9) 757–766 (2007)
UDC *Candida
utilis+663.15:547.963.2:547.392.4, JSCS–3609, doi: 10.2298/JSC0709757G;
Original scientific paper
Effect of fermentation
conditions on lipase production by Candida
utilis
SANJA Z. GRBAVCIC,
Faculty of Technology and Metallurgy, Department
of Biotechnology and Biochemical Engineering, Karnegijeva 4, 11000
(Received
A wild yeast strain isolated from spoiled soybean oil
and identified as Candida utilis initially presented rather low lipase activity
(approximately 4 IU dm-3) in submerged culture in a universal
yeast medium containing 2 % malt extract. Studies were undertaken to
improve the lipase production. The best yields of lipase were obtained with a medium
supplemented with caprylic and oleic acids as inducers, but higher
concentrations of the former (> 0.5 %) had a negative effect on the lipase production and
cell growth. The type of nitrogen source seemed also to be very important. The
highest lipolytic activity of 284 IU dm-3 was achieved after 5 days
of fermentation in a medium containing oleic acid and hydrolyzed casein as
carbon and nitrogen sources, respectively, and supplemented with Tween 80®.
It was shown that optimization of the fermentation conditions can lead to a
significant improvement in the lipase production (more than 70-fold higher
compared to the initial value obtained in the non-optimized medium).
Keywords: Candida utilis, lipase production, media
optimization, hydrolyzed casein, oleic acid.
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J. Serb. Chem. Soc. 72 (8–9) 767–771
(2007)
UDC 546.742:548.736+541.8:547.53,
JSCS–3610, doi: 10.2298/JSC0709767P; Short communication
Disorder of lattice
solvent molecules in the structure of hexaaqua(μ2-1,2,4,5-benzenetetracarboxylato)-bis(2,2’-dipyridylAMine)dinickel(II)
hexahydrate DMSO solvate
DEJAN POLETI, LJILJANA KARANOVIC*,
ALEKSANDAR KREMENOVIC* and JELENA ROGAN
Faculty of Technology and Metallurgy, Karnegijeva 4, 11000
*Faculty of Mining and Geology, Djusina 7, 11000
(Received
The crystal structure of the
complex [Ni2 (btc)(dipya)2(H2O)6]×6H2O·DMSO (btc = tetra-anion
of 1,2,4,5-benzenetetracarboxylic acid, dipya = 2,2’-dipyridylAMine)
was refined in the triclinic system, space group P
, using low temperature (170 K) X-ray diffraction
data. The compound consists of binuclear complex entities and lattice solvent
molecules making pseudo-layers parallel to the 101 plane and channels parallel
to the b-axis. The observed
structural features were compared with the previously reported results and
formula [Ni2(btc)(dipya)2(H2O)6]×4H2O based on room
temperature X-ray diffraction data. A possible arrangement of the disordered
lattice solvent molecules located in the structural channels is described and discussed.
It is concluded that the layout of these molecules is non-centrosymmetric,
although the remaining and main part of the structure is centrosymmetric.
Keywords:
nickel(II) complex, 1,2,4,5-benzenetetracarboxylate ion, 2,2’-dipyridylAMine,
crystal structure, lattice solvent molecules, disorder.
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UDC
541.182.64+546.26+544.478:547.422+541.8, JSCS–3611, doi: 10.2298/JSC0709773B;
Original scientific paper
Characterization of a surface modified
carbon cryogel and a carbon supported Pt catalyst
BILJANA M. BABIC, BRANKA V. KALUĐEROVIC, LJILJANA M VRACAR*, VELIMIR
RADMILOVIC** and NEDELJKO V. KRSTAJIC*
Vinca Institute of Nuclear Sciences, P.O.B. 522, 11001
*Faculty of Technology and Metallurgy,
**
(Received
A carbon cryogel, synthesized by carbonization of a
resorcinol/formaldehyde cryogel and oxidized in nitric acid, was used as
catalyst support for Pt nano-particles. The Pt/C catalyst was prepared by a
modified polyol synthesis method in an ethylene glycol (EG) solution.
Characterization by nitrogen adsorption showed that the carbon cryogel support
and the Pt/C catalyst were mesoporous materials with high specific surface
areas (SBET > 400 m2 g-1) and large
mesoporous volumes. X-Ray diffraction of the catalyst demonstrated the
successful reduction of the Pt precursor to metallic form. TEM Images of the
Pt/C catalyst and Pt particle size distribution showed that the mean Pt
particle size was about 3.3 nm. Cyclic voltAMmetry (CV) experiments at various
scan rates (from 2 to 200 mV s-1) were performed in 0.5 mol dm-3
HClO4 solution. The large capacitance of the oxidized carbon cryogel
electrode, which arises from a combination of the double-layer capacitance and
pseudocapacitance, associated with the participation of surface redox-type
reactions was demonstrated. For the oxidized carbon cryogel, the total specific
capacitance determined by 1/C vs. ν0.5
extrapolation method was found to be 386 F g-1. The hydrogen
oxidation reaction at the investigated Pt/C catalyst proceeded as an
electrochemically reversible, two-electron direct discharge reaction.
Keywords:
carbon cryogel, platinum catalyst, hydrogen oxidation, fuel cell.
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J. Serb.
Chem. Soc. 72 (8–9) 787–797 (2007)
UDC
66.087:546.74+546.56:537.612:621.385.833.001.5, JSCS–3612, doi: 10.2298/JSC0709787N; Original scientific paper
The effects
of a magnetic field on the morphologies of nickel and copper deposits: the
concept of “effective overpotential”
NEBOJSA D. NIKOLIC
ICTM –
(Received
The morphologies of nickel
and copper deposits obtained without applied magnetic fields, and with both
parallel and perpendicular applied magnetic fields were exAMined by the
scanning electron microscopy (SEM) technique. Changes in the morphologies of
the metals caused by the effect of the magnetic fields are explained by the
concept of “effective overpotential”. The morphologies of the nickel and copper
deposits obtained under parallelly oriented magnetic fields were similar to
those obtained at some lower cathodic potentials without an applied magnetic
field. The magnetic field with a perpendicular orientation to the electrode
surface increased the dispersity of the nickel and copper deposits. Nickel and
copper deposits obtained under this orientation of the magnetic field were
similar to those obtained at some higher cathodic potentials without an applied
magnetic field.
Keywords: electrodeposition, magnetic field, copper, nickel, SEM.
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J. Serb. Chem. Soc. 72 (8–9) 799–807 (2007)
UDC 547.854:543.4/.5:541.121:536.7, JSCS–3613, doi: 10.2298/JSC0709799P; Original scientific paper
Spectrophotometric
investigation of the uranyl–phenylephrine system
LEPOSAVA PAVUN, DUSAN MALESEV and DRAGAN
VESELINOVIC*
Faculty of Pharmacy,
*Faculty of Physical Chemistry,
(Received
Using spectrophotometric methods and pH-metric
measurements, it was found that the uranyl ion and phenylephrine form a 1:2
complex in the pH region 2.50 – 4.25 with two absorption maxima at 314.2 nm and
340.6 nm. The thermodynAMic stability constant at I = 0 and T = 298 K (room
temperature) of the UO2(II)–phenylephrine complex, [UO2(C9H12O2N)2]2+,
is log β20= 14.0 and
ΔGÆ2 = –79.6 kJ mol-1.
A linear dependence of the absorbance at 340.6 nm on the concentration of
phenylephrine was obtained in the range from 0.0025 mol dm-3 to
0.0245 mol dm-3 using a solution of 0.025 mol dm-3 UO2(NO3)2
at pH = 3.90 and I = 0.075 mol dm-3.
The measurement error was 2.1 %.
Keywords: complex, uranyl ion,
phenylephrine, thermodynAMic stability constant.
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J. Serb. Chem. Soc. 72 (8–9) 809–819 (2007)
UDC 632.954:543.4/.5, JSCS– 3614, doi: 10.2298/JSC0709809A;
Original scientific paper
Derivative
spectrophotometric determination of the herbicides piclorAM and triclopyr in
mixtures
BILJANA F. ABRAMOVIC*, VESNA B. ANDERLUH*,
FERENC F. GAÁL*,** and DANIELA V. SOJIC*
*Faculty of Sciences, Department of Chemistry,
Trg D. Obradovica 3, 21000
**
(Received
A derivative spectrophotometric method for the
determination of the herbicides piclorAM (4-AMino-3,5,6-trichloropicolinic
acid) and triclopyr (3,5,6-trichloro-2-pyridyloxyacetic acid) in mixtures was
developed in this work. Derivative spectrophotometric determination of the
selected herbicides was preceded by investigations concerning the influence of
pH, in the pH interval from 1 to 9. At pH 3.2, piclorAM and triclopyr solutions
are stable under daylight for nine months. This pH was used for all subsequent
determinations. It was also found that the use of the first derivative of the
spectra at 232 nm was optimal for the determination of piclorAM, while use of
the second derivative of the spectra at 211 nm was best suited for the
determination of triclopyr. The calibration curves are linear in the
concentration range 0.8 – 13 µg cm-3 with correlation coefficients
–0.9998 for piclorAM and 0.9996 for triclopyr. The limit of detection of the
developed method is 0.08 µg cm-3 for piclorAM and 0.03 µg cm-3
for triclopyr. Derivative spectrophotometry was shown to be an appropriate
method for the determination of piclorAM and triclopyr in mixtures and in
pesticide formulations, unlike the deconvolution method.
Keywords: piclorAM, triclopyr,
mixture, derivative spectrometry, zero-crossing method, deconvolution.
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J. Serb. Chem. Soc. 72 (8–9) 821–831 (2007)
UDC 52–656:546.41+543:546.82+546.831:543.4, JSCS– 3615, doi: 10.2298/JSC0709821S; Original scientific paper
Interferences
from titanium and zirconium during calcium determination by flAMe spectrometry
DIMITRIJE DJ. STOJANOVIC, JELENA S. MILINOVIC
and SNEZANA D. NIKOLIC–MANDIC*
Pesticide and Environment Research Institute,
*Faculty of Chemistry,
(Received
Titration methods based on an inhibition
effect were used to investigate the interferences from Ti and Zr in the
determination of Ca by atomic absorption and flAMe emission spectrometry using
an air–acetylene flAMe. Changes either in the absorption or emission signal of
Ca was continuously registered on a computer display and characteristic
titration curves were obtained. The mole ratios between Ti or Zr and Ca at
characteristic points on titration curves were used to explain the quantitative
changes occurring in the solution being titrated and aspirated into the flAMe.
In order to investigate procedures for eliminating these interferences, a
method of atomic absorption inhibition release titration was used. For this
purpose, a solution of La, as a releasing agent with a very low Ca
concentration, used as an indicator, was continuously titrated with the
solution of Ti as inhibitor. A comparative study of the activity of Ba, Sr and
La as releasing agents was investigated during titration of Ca with Zr
solution. Based on the calculated mole ratios between Zr and Ba, Sr or La, the
effectiveness of these agents in eliminating the interferences was determined.
Possible reactions occurring during evaporation of the aerosol in the
air–acetylene flAMe are represented by chemical equations.
Keywords: interference, calcium
determination, titanium and zirconium, flAMe atomic absorption and emission
spectrometry, titration method, releasing action.
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J. Serb. Chem. Soc. 72 (8–9) 833–846 (2007)
UDC 547.221:536.2:536.7:536.423.1, JSCS–3616, doi: 10.2298/JSC0709833D; Original scientific paper
Mean
heat transfer coefficients during the evaporation of 1,1,1,2-tetrafluoroethane
(R-134a) in a plate heat exchanger
EMILA DJORDJEVIC, STEPHAN KABELAC* and
SLOBODAN SERBANOVIC
Faculty of Technology and Metallurgy,
*
(Received
In this study the transfer coefficient of
evaporation heat of the refrigerant 1,1,1,2-tetrafluoroethane (R-134a) in a
vertical plate heat exchanger was experimentally investigated. The results are
presented as the dependancy of the mean heat transfer coefficient for the whole
heat exchanger on the mean vapor quality. The influences of mass flux, heat
flux and flow configuration on the heat transfer coefficient were also taken
into account and a comparison with previously published experimental data and
literature correlations was made.
Keywords: plate heat exchanger,
evaporation, 1,1,1,2-tetrafluoroethane, heat transfer coefficient.
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UDC 546.214+541.183+66.023:66.021.3+543.552, JSCS–3617, doi: 10.2298/JSC0709847T; Original scientific paper
Ozone
absorption in a mechanically stirred reactor
LJILJANA TAKIC, VLADA VELJKOVIC, MIODRAG LAZIC
and SRDJAN PEJANOVIC*
*
(Received
Ozone absorption in water was investigated in
a mechanically stirred reactor, using both the semi-batch and continuous mode
of operation. A model for the precise determination of the volumetric mass
transfer coefficient in open tanks without the necessity of the measurement the
ozone concentration in the outlet gas was developed. It was found that slow
ozone reactions in the liquid phase, including the decomposition of ozone, can
be regarded as one pseudo-first order reaction. Under the exAMined operating
conditions, the liquid phase was completely mixed, while mixing in a gas phase
can be described as plug flow. The volumetric mass transfer coefficient was
found to vary with the square of the impeller speed.
Keywords: ozone, absorption, stirred
reactor, volumetric mass transfer coefficient
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J. Serb. Chem. Soc. 72 (8–9) 857–868 (2007)
UDC 546.152’57:548.7:544.015.4, JSCS–3618, doi: 10.2298/JSC0709857V;
Original scientific paper
Crystalline
forms of silver iodide II. Determination of phase transformations
MARIJA R. VUKIC, DRAGAN S. VESELINOVIC* and
VESNA G. MARKOVIC**
Institute “Kirilo Savic” a. d., Vojvode Stepe
51, 11000
*Faculty of Physical Chemistry, Studentski trg
12,
**ITNMS, Franchet d’Esperey Str. 86, 11000 Belgrade,
Serbia
(Received
In order to obtain appropriate forms of AgI
(β- and γ-), a procedure was developed to synthesize AgI at room temperature
(23 °C), whereby sAMples of varying crystallographic purity and of varying
crystallographic contents of the differrent forms were obtained. This paper
presents the results of investigations of the influence of the manner of
preparation of β-AgI and γ-AgI sAMples and the sAMple heating rate on the phase
transformations and their temperatures. During the heating of non-ground,
ground and pressed synthesized AgI sAMples, the phase transformations and the
corresponding temperatures for one β-AgI and four γ-AgI sAMples with different
β-AgI contents (representing a crystallographic impurity) were identified. The
following phase transformations were observed for the non-ground AgI sAMples:
β-AgI → α-AgI at 149.6 °C (for the β-AgI sAMple) and γ-AgI → α-AgI at 148.7 °C
or 148.2 °C for the γ-AgI sAMples with a minimum content of β-AgI (less than 7
%), as a crystallographic impurity. The phase transition γ-AgI → α-AgI was
irreversible because β-AgI was obtained whenever the sAMples were heated up to
260 °C. Manual sAMple grinding, as well as pressing at p1 = 650 MPa and p2
= 900 MPa resulted in the β-AgI → γ-AgI phase transition in all the
investigated cases.
Keywords: silver iodide, heat
treatment, mechanical treatment, phase transformation, DSC, X–ray diffractometry
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UDC 661.892:544.478:662.62:66.041, JSCS–3619, doi: 10.2298/JSC0709869B; Original scientific paper
Properties
and efficiency of a Pt/Al2O3 catalyst applied in a solid
fuel thermo-accumulating furnace
SRDJAN BELOSEVIC, RASTKO MLADENOVIC, DRAGOLJUB
DAKIC, MILIJANA PAPRIKA, ALEKSANDAR ERIC, DEJAN DJUROVIC, MIRKO KOMATINA*,
BOSKO GRBIC** and NENAD RADIC**
Vinča Institute of Nuclear Sciences,
Laboratory for Thermal Engineering and Energy, P.O. B. 522, 11001
*Faculty of Mechanical Engineering, Kraljice
Marije 16, 11000
**
(Received
A prototype of a solid fuel
thermo-accumulating furnace has been developed. In order to achieve a higher
combustion efficiency, a Pt/Al2O3 catalyst in the form of
3 ± 0.3 mm spheres was applied, which enabled further combustion of flue
gases within the furnace. Experimental investigation of the influence of the
catalyst on the conversion of CO has been done for different operation regimes
and positions of the catalyst. Paper presents selected results regarding CO
emission during wood and coal combustion. Investigations suggest a considerable
effect of the catalyst and a strong influence of the catalyst position to CO
emission reduction. The microstructure of the catalyst beads, characterized by
selective chemisorption of CO, has shown the decrease of the number of Pt sites
as a consequence of blockage by coke deposits formed during the combustion of
solid fuel.
Keywords: Pt/Al2O3
catalyst, emission reduction, solid fuel, thermo-accumulating furnace.
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UDC 541.182.3+66.061:632.95:541.121:544.4, JSCS–3620, doi: 10.2298/JSC0709879D; Original scientific paper
Headspace solid phase microextraction in
the analysis of pesticide residues – kinetics and quantification prior to the
attainment of partition equilibrium
RADA DJUROVIC, MIRJANA MARKOVIC and DRAGAN MARKOVIC*
Institute of Pesticide and Environmental Protection,
Banatska 31b, P.O.B. 163, 11080 Belgrade, Serbia
*Faculty of Applied Ecology FUTURA, Bulevar Kralja
Aleksandra 79, 11000 Belgrade, Serbia
(Received
A new theoretical approach to the
headspace/solid phase microextraction (HS/SPME) process is proposed and tested
by the analysis of pesticide residues of water sAMples. The new approach
focuses on mass transfer at the sAMple/gas phase and gas phase/SPME polymer
interfaces. The presented model provides a directly proportional relationship
between the AMount of analytes sorbed by the SPME fiber and their initial
concentrations in the sAMple. Also, the expression indicates that
quantification is possible before partition equilibrium is attained.
Experimental data for pesticides belonging to various classes of organic
compounds were successfully interpreted by the developed model. Additionally, a
linear dependence of the AMount of pesticide sorbed on the initial analyte
concentration in aqueous solution was obtained for a sAMpling time shorter than
that required to reach sorption equilibrium.
Keywords: HS/SPME, theoretical model,
pesticide residues.
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UDC 614.71:504.06(497.11), JSCS–3621, doi: 10.2298/JSC0709889Z;
Original scientific paper
The characteristics
of the air pollution of a transition economy city: the exAMple of Belgrade
ALEKSANDRA M. ZUJIC, BOJAN B. RADAK and DRAGAN A.
MARKOVIC*
Vinca Institute of Nuclear Sciences,
Laboratory for Physical Chemistry,
*Faculty of Applied Ecology,
(Received
The results of sulphur dioxide (SO2),
nitrogen dioxide (NO2) and black smoke (BS) levels in the Belgrade
metropolitan area, the only pollutants measured at almost all 20 monitoring
stations set up in the area, were critically analysed, the most reliable ones
select and the pollution characteristics were defined in these terms.
Keywords: urban air pollution, air
quality, monitoring,
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UDC 536.7+544.015.3+519.6:546.57’87.’811, JSCS–3622, doi: 10.2298/JSC0709901Z; Original scientific paper
ThermodynAMics
and phase diagrAM calculation of some sections in the Ag–Bi–Sn system
DRAGANA ZIVKOVIC, IWAO KATAYAMA*, DRAGAN
MANASIJEVIC, HIROMI YAMASHITA* and NADA STRBAC
*
(Received
The thermodynAMic properties and
characteristic phase diagrAMs of some sections in the Ag–Bi–Sn system were
calculated. The thermodynAMic functions, such as Gibbs excess energy, activity
and enthalpy of formation, were calculated using the RKM model and compared
with experimental data reported in the literature. Iso-activity diagrAMs for
all three components at 900 K have been constructed. The calculated phase
diagrAMs of the vertical sections Sn–AgBi, Ag–BiSn and Bi–AgSn, obtained using
the ThermoCalc progrAM, were compared and confirmed with the results of DTA
measurements from the present work.
Keywords: thermodynAMics, phase
diagrAMs, ternary alloys, Ag–Bi–Sn system, lead-free solders.
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UDC 549.352.12+546.326–325+622.234.4:54–72, JSCS–3622, doi: 10.2298/JSC0709911A; Original scientific paper
Influence
of grain size on chalcopyrite ore leaching in acidic medium
M. M. ANTONIJEVIC, G. D. BOGDANOVIC, S. M.
SERBULA and S. M. MILIC
University of Belgrade, Technical Faculty Bor,
Department of Chemistry and Chemical Technology, P.O. Box 50, 19210 Bor, Serbia
(Received
This work presents an investigation of column
leaching of a chalcopyrite ore using sulphuric acid where dissolved oxygen and
iron(III) ions play the role of oxidants. The investigations were carried out
in PVC columns, diAMeter 110 mm and height 1000 mm, by percolation of the
leaching solution through the ore layer. The influence of ore grain size on the
degree of leaching and acid consumption was exAMined. The formation of gypsum
on limestone results in the comminution of the initial raw material during
leaching. The grain size of chalcopyrite was found to have no important
influence on the leaching rate of copper. A higher consumption of sulphuric
acid was found for the fractions (–3+1) mm, (5+0) mm and (5+3) mm than for the fractions (10+5) mm, (20+10) mm and (20+0)
mm.
Keywords: chalcopyrite ore, column
leaching, grain size.
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