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Full-Text Articles in Engineering Science and Materials

Conceptual Design For Treatment Of Mining And Metallurgical Wastewaters Which Contains Arsenic And Antimony, Zeljko J. Kamberovic Jan 2012

Conceptual Design For Treatment Of Mining And Metallurgical Wastewaters Which Contains Arsenic And Antimony, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper presents a preliminary design for treatment of mining and metallurgical wastewaters (MMW) from the basin of antimony “Zajača“, which contains high concentrations of arsenic and antimony. MMW have been investigated in laboratory, due to large difference in concentrations of pollutants. Metallurgical wastewaters were treated using iron (II)-sulfate and lime milk used to adjust the pH value at 7. After chemical treatment of metallurgical wastewater and its joining with mining wastewater, residual amount of arsenic in water was below maximum allowed concentrations, while the concentration of antimony, remained above the maximum allowed value. The final phase of purification ...


Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part Ii: Development Of The Processes For The Recovery Of Copper From Printed Circuit Boards (Pcb), Zeljko J. Kamberovic Aug 2011

Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part Ii: Development Of The Processes For The Recovery Of Copper From Printed Circuit Boards (Pcb), Zeljko J. Kamberovic

Zeljko J Kamberovic

Rapid technological development induces increase of generation of used electric and electronic equipment waste, causing a serious threat to the environment. Waste printed circuit boards (WPCBs), as the main component of the waste, are significant source of base and precious metals, especially copper and gold. In recent years, most of the activities on the recovery of base and precious metals from waste PCBs are focused on hydrometallurgical techniques as more exact, predictable and easily controlled compared to conventional pyrometallurgical processes. In this research essential aspects of the hydrometallurgical processing of waste of electronic and electrical equipment (WEEE) using sulfuric acid ...


The Analysis Of The Tribological Properties Of Multiple Strengthened Nanocomposite Of The Cu-Al2o3 System, Zeljko J. Kamberovic Dec 2010

The Analysis Of The Tribological Properties Of Multiple Strengthened Nanocomposite Of The Cu-Al2o3 System, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper presents the results of examined tribological properties of the multiple strengthened nanocomposite Cu-Al2O3 system. Cu-Al2O3 composite powder was obtained by combination of the thermo-chemical procedure and mechanical alloying, which is a completely new approach to synthesis of these materials. The synthesized powders were cold pressed with 940MPa and sintered in hydrogen atmosphere in temperature range of 725-925o C during 15-120 minutes. The samples were thermo- mechanically treated in two stages after sintering: cold rolling with the final reduction degree of 30% and annealing at 800o C for 1h in hydrogen atmosphere. Characterization of the sintered, rolled and annealed ...


Possibility Of Secondary Lead Slag Stabilization In Concrete With Presence Of Selected Additives, Zeljko J. Kamberovic Jan 2010

Possibility Of Secondary Lead Slag Stabilization In Concrete With Presence Of Selected Additives, Zeljko J. Kamberovic

Zeljko J Kamberovic

A comparative technical and environmental evaluation of products arising from the stabilization/solidification of secondary lead metallurgical slag into a cement matrix was performed. Provided samples of an industrial slag generated in the process of recovery of lead from automotive batteries (Engitec CX process), were used in experimental work. Characterization of slag by X-ray Diffraction (XRD), Atomic Absorption Spectrometry (AAS) and Optical Microscopy (OM) revealed that slag contains a certain percentage of sodium and lead, in the form of oxides and sulphides, as well as unreacted coke and iron compounds. Dissolving of the slag components causes migration of ions into ...


Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part I: Material Characterization And Process Option Selection, Zeljko J. Kamberovic Dec 2009

Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part I: Material Characterization And Process Option Selection, Zeljko J. Kamberovic

Zeljko J Kamberovic

Used electronic equipment became one of the fastest growing waste streams in the world. In the past two decades recycling of printed circuit boards (PCBs) has been based on pyrometallurgy, higly polluting recycling technology whic causes a variety of environmental problems. The most of the contemporary research activities on recovery of base and precious metals from waste PCBs are focused on hydrometallurgical techniques as more exact, predictable and easily controlled. In this paper mechanically pretrated PCBs are leached with nitric acid. Pouring density, percentage of magnetic fraction, particle size distribution, metal content and leachability are determined using optical microscopy, atomic ...


Effect Of Non-Stationary Current Regimes On The Morphology Of Silver Electrodeposits, Zeljko J. Kamberovic Jan 2009

Effect Of Non-Stationary Current Regimes On The Morphology Of Silver Electrodeposits, Zeljko J. Kamberovic

Zeljko J Kamberovic

This work is concerned with the use of reverse current regimes in order to form small-grained and compact silver deposits during the electrorefining process. Several parameters were varied, i.e., i) anodic overpotential, ii) cathodic vs. anodic time ratio and iii) duration of the anodic pulse. After optimization of these parameters, phosphate ions were added and the electrolyte was stirred. The effects of a rise of the anodic overpotential on the grain sizes of the silver deposit and compactness were studied. Prolongation of the anodic time had a similar influence but with a decrease in current efficiency. An increase of ...


Cleaner Metallurgical Industry In Serbia: A Road To The Sustainable Development, Zeljko J. Kamberovic Dec 2008

Cleaner Metallurgical Industry In Serbia: A Road To The Sustainable Development, Zeljko J. Kamberovic

Zeljko J Kamberovic

Since the sustainable development has been a global and fundamental objecttive, a metallurgical industrial sector faces some of the most difficult sustainability challenges of any industrial sector. On the other hand, the metallurgical production in Serbia is a very important part of the economy. Due to present facilities and technologies, metallurgical companies face a great challenge to fulfill the requirements introduced by legislature referring to the cleaner production and sustainable development. The state of art in the production, facilities, pollution with some answers to imposed challenges is presented.


Nanocomposite Powders For New Contact Materials Based On Copper And Alumina, Zeljko J. Kamberovic Jan 2008

Nanocomposite Powders For New Contact Materials Based On Copper And Alumina, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper is a contribution to characterization of Cu-Al2O3 powders with nanostructure designed for the production of dispersion strengthened contact materials. New materials with predetermined properties can be successfully synthesized by utilizing the principles of hydrometallurgy and powder metallurgy. The results show a development of a new procedure for the synthesis. The applied characterization methods were differential thermal and thermogravimetric analysis (DTA-TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM): Focused Ion Beam (FIB) and Analytical Electron Microscopy (AEM). Nanostructure characteristics, particle size in range 20-50 nm, and uniform distribution of dispersoide in copper matrix were validated.


Determination Of Al2o3 Particle Size In Cu-Al2o3 Nanocomposite Materials Using Uv Spectrophotometry, Zeljko J. Kamberovic Jan 2008

Determination Of Al2o3 Particle Size In Cu-Al2o3 Nanocomposite Materials Using Uv Spectrophotometry, Zeljko J. Kamberovic

Zeljko J Kamberovic

In order to achieve improved mechanical properties of dispersion strengthened nanocomposite, without influencing electrical and thermal conductivity it is necessary for dispersoide to be nano sized and uniformly distributed in base metal matrix. In this paper are presented the results concerning possibility of using UV spectrophotometry for determination of alumina particle size in Cu-Al2O3 system. Presented results show that this method is unefficient as method for determination of dispersoide particle size, due to the coalescence of particles false results are obtained, i.e. particle size significantly higher then one determined by image analysis.


Structural Characteristics Of Some Ternary Ag-In-Sn Alloys, Zeljko J. Kamberovic Jan 2008

Structural Characteristics Of Some Ternary Ag-In-Sn Alloys, Zeljko J. Kamberovic

Zeljko J Kamberovic

The Ag-In-Sn system, as one of potential lead-free solder materials, was studied in this paper. The investigated alloys were chosen from two sections, with molar ratio of In:Sn equal to 1:4; 1:2. DTA, XRD, SEM and microhardness investigations were used in order to determine structural characteristics of chosen Ag-In-Sn ternary alloys.


Structure And Kinetics Of Internal Oxidation In Ag-Sn Alloys, Zeljko J. Kamberovic Dec 2007

Structure And Kinetics Of Internal Oxidation In Ag-Sn Alloys, Zeljko J. Kamberovic

Zeljko J Kamberovic

Internal oxidation in Ag-Sn-In-Te and Ag-Sn-Cu-Bi alloys was tested. Microstructures of casted and homogenized samples, as well as after internal oxidation were followed by optical microscopy. The structure of Ag-Sn-Cu-Bi alloy was found finer, and the oxidation rate is considerably higher compared to the Ag-Sn-In-Te type alloy sheets. It seems that the size and volume fraction of secondary phase particles (probably ζ type) can influence the process of internal oxidation. In the Ag-Sn-In-Te alloy type “wavy oxidation” was noticed with oxide free regions.


Selective Removal Of Heavy Metals From Metal-Bearing Wastewater In A Cascade Line Reactor, Zeljko J. Kamberovic Jan 2007

Selective Removal Of Heavy Metals From Metal-Bearing Wastewater In A Cascade Line Reactor, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper is a part of the research work on 'Integrated treatment of industrial wastes towards prevention of regional water resources contamination – INTREAT' the project. It addresses the environmental pollution problems associated with solid and liquid waste/effluents produced by sulfide ore mining and metallurgical activities in the Copper Mining and Smelting Complex Bor (RTB-BOR), Serbia. However, since the minimum solubility for the different metals usually found in the polluted water occurs at different pH values and the hydroxide precipitates are amphoteric in nature, selective removal of mixed metals could be achieved as the multiple stage precipitation. For this reason ...


Sintering Of Cu–Al2o3 Nano-Composite Powders Produced By A Thermochemical Route, Zeljko J. Kamberovic Jan 2007

Sintering Of Cu–Al2o3 Nano-Composite Powders Produced By A Thermochemical Route, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper presents the synthesis of nano-composite Cu–Al2O3 powder by a thermochemical method and sintering, with a comparative analysis of the mechanical and electrical properties of the obtained solid samples. Nano-crystalline Cu–Al2O3 powders were produced by a thermochemical method through the following stages: spray-drying, oxidation of the precursor powder, reduction by hydrogen and homogenization. Characterization of powders included analytical electron microscopy (AEM) coupled with energy dispersive spectroscopy (EDS), differenttial thermal and thermogravimetric (DTA–TGA) analysis and X-ray diffraction (XRD) analysis. The size of the produced powders was 20–50 nm, with a noticeable presence of agglomerates. The composite ...


Synthesis And Sintering Of Cu-Al2o3 Nanocomposite Powders Produced By A Thermochemical Route, Zeljko J. Kamberovic Jan 2007

Synthesis And Sintering Of Cu-Al2o3 Nanocomposite Powders Produced By A Thermochemical Route, Zeljko J. Kamberovic

Zeljko J Kamberovic

By hydrometallurgy and powder metallurgy along with prognosis of physical- chemical properties, a synthesis of new improved materials can be successfully performed with in advance pre-set properties which is conditioned by a quality of starting powders i.e. by improving their structure. In accordance with that, this paper presents synthesis of the nanocomposite Cu-Al2O3 powder by thermochemical method and sintering with a comparative analysis of the mechanical and electrical properties of obtained solid samples. Nanocrystaline Cu-Al2O3 powders were produced by thermochemical method through following stages: spray-drying, oxidation of precursor powder, reduction by hydrogen and homogenisation. Characterization of powders included differential-thermal ...


The Synthesis Of Ultrafine And Nanocomposite Powders Based On Copper, Silver And Alumina, Zeljko J. Kamberovic Jan 2006

The Synthesis Of Ultrafine And Nanocomposite Powders Based On Copper, Silver And Alumina, Zeljko J. Kamberovic

Zeljko J Kamberovic

Contemporary materials with predetermined properties can be successfully synthesized by utilising the principles of hydrometallurgy and powder metallurgy. The results of developing a new procedure for the synthesis of ultrafine and nanocomposite powders based on copper, silver and alumina are presented in this paper. A two-component nanocomposite powder, Cu-Al2O3, was synthesized by a thermochemical procedure, by deposition from an aqueous solution of soluble metal salts, Cu(NO3)2 and Al(NO3)3. A three-component Cu-Ag-Al2O3 powder was produced by mechanically alloying nanocomposite Cu-Al2O3 powder and Cu-Ag powder, synthesized by the thermochemical procedure. The produced powders were characterized by determining the ...


The Influence Of Titanium And Cerium On Microstructure And Properties Of Fe-C-Cr-Nb Alloys, Zeljko J. Kamberovic Jan 2005

The Influence Of Titanium And Cerium On Microstructure And Properties Of Fe-C-Cr-Nb Alloys, Zeljko J. Kamberovic

Zeljko J Kamberovic

In this paper, the influence of titanium and cerium on the microstructure and properties of Fe- C-Cr-Nb alloys are examined, in both as-cast and heat treated state. These elements affect the crystallisation process of Fe-C-Cr-Nb alloys and the transformation of austenite during the cooling process after solidification. Titanium changed the morphology of NbC carbides. Further, in the austenite of the examined Fe-C-Cr-Nb-Ti alloys, very fine particles of precipitated secondary carbide can be seen. The alloy containing 0,28%Ti and 0,19%Ce has martensite-perlite-austenitic matrix microstructure in as-cast condition. Adding titanium and cerium to Fe-C-Cr-Nb alloys will also changed ...


Possibilities Of Recycling Of Magnesium And Magnesium Alloys, Zeljko J. Kamberovic Jan 2004

Possibilities Of Recycling Of Magnesium And Magnesium Alloys, Zeljko J. Kamberovic

Zeljko J Kamberovic

In this paper are presented results of experimental investigation of processing of non oil-contaminated metal scrap based on magnesium and its alloys. These are the firs investigations of magnesium scrap recycling in Serbia and Montenegro. Experimental investigations were conducted in laboratory scale and achieved results were verified in industrial scale (Magnesium factory ″Bela Stena″ in Baljevac on Ibar). Experiments included following the influence of preparation of metal scrap on metal extraction efficiency rate.


Development Of Contemporary Procedures For Lead Obtaining, Zeljko J. Kamberovic Jan 2004

Development Of Contemporary Procedures For Lead Obtaining, Zeljko J. Kamberovic

Zeljko J Kamberovic

Contemporary procedures of lead concentrates treatment were in different expansion during last thirty years. All procedures have in common the following: smelting reaction proceeds in solid-gas suspension, melting products are metallic lead and slag, which are leaving electric furnace together. The conditions for production metallic lead and slag in one furnace are determined using thermodynamic analysis of contemporary direct smelting procedures. The characteristics and progress of direct smelting process are determined using oxygen/concentrate ratio, which influences the lead content in slag, sulphur content in bullion and the following metals distribution. The KIVCET and Boliden TBRC are contemporary procedures that ...


Optimisation Of Ferriferous Dust And Mud Preparation Acts From Iron And Steel Production On Purpose Of Returning To Primary Processes, Zeljko J. Kamberovic Jan 2004

Optimisation Of Ferriferous Dust And Mud Preparation Acts From Iron And Steel Production On Purpose Of Returning To Primary Processes, Zeljko J. Kamberovic

Zeljko J Kamberovic

In this paper detailed characterization of ferriferous dust and mud which originated from aglomerization, blast- furnace and converter process in Iron-works Smederevo were shown. Optimization of method peletization was conducted in variably conditions (different moinsture content, changing of time of peletization and type of binder). These palets were submitted to examination of resistance on impact and pressure, and their behavior was confirmed returning in sintering process in semiindustrial conditions. Ideally-technological solution for plant preparation of dust and mud in Iron-works Smederevo was recommanded. That solution should contribute to improvement of techno-economic parametars of aglomeration and blast- furnace process, as well ...


On The Physicochemical Problems Of Aqueous Oxidation Of Polymetallic Gold Bearing Sulphide Ore In An Autoclave, Zeljko J. Kamberovic Jan 2003

On The Physicochemical Problems Of Aqueous Oxidation Of Polymetallic Gold Bearing Sulphide Ore In An Autoclave, Zeljko J. Kamberovic

Zeljko J Kamberovic

The paper presents a study on the physical and chemical changes of iron, copper and zinc sulphide minerals in process of pressure oxidation. Oxidation in autoclave is a pre-treatment unit operation for refractory sulphide ores and concentrates in order to valorisat gold, which is encapsuled mainly in pyrite matrix. Raw materials and solid residues are charasterisated. Basing on the results of chemical reactions and on shape of solids residue, we came to a conclusion concerning the mechanism of oxidation in autoclave. The results show that modelling of the process parameters of oxidation in autoclave can be used to predict efficiency ...


Leaching Of Copper(I) Sulphide By Sulphuric Acid Solution With Addition Of Sodium Nitrate, Zeljko J. Kamberovic Jan 2003

Leaching Of Copper(I) Sulphide By Sulphuric Acid Solution With Addition Of Sodium Nitrate, Zeljko J. Kamberovic

Zeljko J Kamberovic

Finely grained samples of copper(I) sulphide were leached by H2SO4 solution with added NaNO3. The occurrence probability of chemical reactions was analysed based on literature data and products which were formed during the process and the overall leaching reaction was defined. The effect of temperature, concentration of NaNO3 and H2SO4, stirring speed, phase ratio and time, on the leaching degree of copper was studied. The quantity of copper dissolved increases with growth of the values of all the parameters. Kinetic analysis shows that the leaching mechanism is very complex. By using appropriate mathematical kinetic models, it is found that ...


Study Of Chlorination Of Nickel Ferrite By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic Jan 2000

Study Of Chlorination Of Nickel Ferrite By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic

Zeljko J Kamberovic

Thermodynamic analysis and experimental research of the chlorination of nickel ferrite (NiFe2O4) by gaseous chlorine in the presence of added C, BaS, S and NaCl in the temperature range from 300 to 900¾C are given in this paper. Nickel ferrite chlorination in the presence of BaS and CaCl2 was carried out in the temperature range from 750 to 950¾C. The presence of added C, BaS, S and NaCl intensifies the chlorination process of nickel ferrite by gaseous chlorine and reduces the temperature the reaction begins at from 700 to 300¾C. It is concluded that the process of nickel chlorination without ...


Study Of Chlorination Of Nickel Silicate By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic Jan 2000

Study Of Chlorination Of Nickel Silicate By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic

Zeljko J Kamberovic

The paper presents a thermodynamic analysis and experimental research on the kinetics of the chlorination of nickel silicate (2NiOÀSiO2) by gaseous chlorine and calcium chloride without additives and in the presence of added C, BaS, S and NaCl, to intensify the process. The influence of temperature in the range from 673 up to 1223 K for various chlorination times has been studied. Additives increases the chlorination rate. The kinetics of the process were determined by the analysis of dependence of the nickel chlorination rate on time and temperature. It was established that nickel chlorination without additives is a chemically-controlled reaction ...