The aim of this study is to investigate the utility of adding chelating agent during hydrochloric... more The aim of this study is to investigate the utility of adding chelating agent during hydrochloric acid leaching of low-grade scheelite concentrates, obtained from Uluda , Bursa (Türkiye). Examined parameters were as follows; leaching conditions, selective precipitation of tungsten salt ...
In this study, the possibility of utilizing high current densities in copper rening electrolysis ... more In this study, the possibility of utilizing high current densities in copper rening electrolysis was investigated in relation to the cell design along with the surface characteristics of cathode material, and the changes observed in cell potential depending on the working conditions. Two groups of experiments were conducted. The rst series of copper rening electrolyses were carried out without any additives to the bath whereas in the second series, the eect of glue, thiourea, and chloride additions to the bath on cathodic copper was examined. Electrolysis conditions, in accordance with industrial practice, kept constant in both sets of experiments and were as follows: 45 g Cu 2+/L, 150 g H2SO4/L, 55C, electrolyte circulation of 15-20 L/min, anode dimensions of 78 74 4.5 mm, copper cathode of 47 85x0.1 mm, current density of 700 A/m2, and the aforesaid additives. Lab-scale high current density copper rening electrolysis was carried out in a specially designed cell with a unique elect...
The aim of this study is to investigate the utility of adding chelating agent during hydrochloric... more The aim of this study is to investigate the utility of adding chelating agent during hydrochloric acid leaching of low-grade scheelite concentrates, obtained from Uluda , Bursa (Türkiye). Examined parameters were as follows; leaching conditions, selective precipitation of tungsten salt ...
International Journal of Mineral Processing and Extractive Metallurgy
The consumption of mobile phones is increasing day by day and the replacement speed is also accel... more The consumption of mobile phones is increasing day by day and the replacement speed is also accelerating. Thus, a lot of old mobile phones and their parts need to be processed. Mobile phones contain more than 40 elements and/or materials. This experimental study aims to establish the possibilities of recovering valuable metals from waste mobile phones by using acidic leaching. The process steps include dismantling of waste mobile phones, pre-processing to liberate the materials, and directing them to final treatment processes. Prior to leaching tests, the PCBs of waste mobile phone sample are chemically analyzed and its metal contents are found as 33.22% Cu, 9.42% Fe, 1.86% Zn, 2.77% Ni, 1.63% Al, 0.4% Pb, 0.02% Co, 0.14% Ag, and 251.2 ppm Au. In the leaching experiments, sulfuric, nitric, and hydrochloric acids are used. In the sulfuric acid leaching experiments, effects of acid concentration, temperature, hydrogen peroxide addition, and leaching periods on metal dissolution efficiencies are investigated. Results are compared and discussed in relation to the types of acids. XRD analyses of feed material and leach residues are also carried out. As a result of this experimental study, 97.9% Fe leaching in 8 M H 2 SO 4 solutions, 89% Pb, 100% Ni, 90.4% Co, and 4.1% Cu leaching in 1M HNO 3 solutions, 100% Pb, and 100% Al leaching in 4 M HCl solutions in one hour are found. In conclusion, sequential leaching with different acids is recommended for the effective leaching of all metals.
The hydrometallurgical route of zinc hydroxide and synthesis of nanocrystalline ZnO is a particul... more The hydrometallurgical route of zinc hydroxide and synthesis of nanocrystalline ZnO is a particularly attractive method to recover oxidized lead and zinc from lead-zinc flotation tailings. In Turkey, lead-zinc complex/mixed ores along with high iron content are not suitable for conventional mineral processing methods and need hydrometallurgical treatments. Therefore, the control of iron during zinc processes is really important. In this study, hydrometallurgical process route for zinc recovery from Pb-Zn flotation tailings was investigated by considering the effects of H2SO4 concentration, leaching and roasting temperatures on the zinc dissolution considering the Eh-pH variations. The iron and zinc products were also individually examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images in order to compare before and after leaching, precipitation and roasting steps. 83.1% Zn and 91.6% Cd leaching efficiencies were obtained from ...
Journal of Nanoelectronics and Optoelectronics, 2020
ZnO nanowire arrays were fabricated by hydrothermal growth on Al-doped ZnO (ZnO:Al) seed layers c... more ZnO nanowire arrays were fabricated by hydrothermal growth on Al-doped ZnO (ZnO:Al) seed layers coated on soda-lime silicate glass by sol–gel coating. The properties of the ZnO:Al seed layer were evaluated to obtain ZnO nanowires with the optimal size and length and to realize suitable adhesion of the ZnO:Al grains to the substrate. The optimal mechanical performance (adhesion and abrasion resistance) of the ZnO:Al seed layer was obtained at Al 1 at.%. The seed layers annealed between 400 and 500 C exhibited enhanced ZnO nanowire growth. Increasing the annealing temperature within this range improved the electrical and optical properties of the nanowires. Additionally, two chemical compounds, zinc acetate (ZA) and zinc nitrate (ZN), were used to compare the effects of the solution type on the hydrothermal growth. The nanowires grown in the ZA solution were thicker and had higher electrical conductivity compared to the ZN solution. The gamma transmission technique was used to determi...
Two electrochemical reactions proceed simultaneously at the anode: the evolution of oxygen and th... more Two electrochemical reactions proceed simultaneously at the anode: the evolution of oxygen and the oxidation of Cr(III) to Cr(VI). The Cr(VI) diffuses from the anode compartment through the diaphragm, and it reacts with Cr(II) in the catholyte. Since the current efficiency for ...
The hydrometallurgical treatment of zinc sulfide concentrates involves the separation of zinc fro... more The hydrometallurgical treatment of zinc sulfide concentrates involves the separation of zinc from iron, since most zinc concentrates contain 5-12% iron. Several processes, such as hematite, magnetite, goethite and jarosite, have been developed for the removal of iron ...
Material Science & Engineering International Journal
In this study, solvent extraction is applied for extracting nickel from sulfate solutions contain... more In this study, solvent extraction is applied for extracting nickel from sulfate solutions containing iron and cobalt ions. This process can also be applied for the cleaning of waste solutions and for increasing solution concentrations after the leaching of low-grade nickel ores. Di-2-Ethylhexyl phosphoric acid (D2EHPA) was used as an extractant for this purpose. Effects of pH, aqueous/organic (A/O) phase ratio, iron, and cobalt ion contents of the solution on nickel extraction efficiency were investigated. The McCabe-Thiele diagrams for extraction and stripping steps were developed to determine the number of stages required. A total of two stages were required for 96.3% of Ni extraction and a total of two stages to strip nickel with 98% efficiency.
The possibility of producing metallic chromium from Cr2O3 via the aluminothermic route, with no e... more The possibility of producing metallic chromium from Cr2O3 via the aluminothermic route, with no external energy supply, was the subject of this laboratory-scale research. The experimental study focused on investigating the individual effects and quantitative optimization of the charge contents, i.e., the additions of CrO3, Al powder and CaO (or BaO). The highest chromium recovery of 98% was attained with the additions of 12% CrO3 and 1.2 times the stoichiometric ally required amount of Al powder. The optimum CaO addition giving the highest chromium recovery was found when the CaO/Al weight ratio in the charge was equal to 0.3. When BaO was used, however, 95% Cr extraction efficiency was obtained at a BaO/Al weight ratio ofO. 15.
For the worldwide steel production of 725 Mt in 1993, 503 Mt of hot metal, 24 Mt of sponge iron, ... more For the worldwide steel production of 725 Mt in 1993, 503 Mt of hot metal, 24 Mt of sponge iron, and about 400 Mt of scrap were used. Today, the share of electric arc furnaces in this steel production is about 30%, meaning that every third ton of the steel produced worldwide is made by recycled scrap. This percentage is even higher in Turkey where two-thirds of the steel produced is manufactured from scrap. Although no major increase in steel production is anticipated in the near future, any that does occur will be via electric arc furnaces, which will increase the demand for scrap. In the future, a decrease in the amount of circulating scrap and a slight increase in process scrap are expected ; thus, the increased demand for scrap will be balanced mostly by the capital scrap. These developments might cause a drop in the quality of scrap. Many problems have to be solved in the future with scrap processing and recycling. This must be achieved by cooperation between the steel producin...
The aim of this study is to investigate the utility of adding chelating agent during hydrochloric... more The aim of this study is to investigate the utility of adding chelating agent during hydrochloric acid leaching of low-grade scheelite concentrates, obtained from Uluda , Bursa (Türkiye). Examined parameters were as follows; leaching conditions, selective precipitation of tungsten salt ...
In this study, the possibility of utilizing high current densities in copper rening electrolysis ... more In this study, the possibility of utilizing high current densities in copper rening electrolysis was investigated in relation to the cell design along with the surface characteristics of cathode material, and the changes observed in cell potential depending on the working conditions. Two groups of experiments were conducted. The rst series of copper rening electrolyses were carried out without any additives to the bath whereas in the second series, the eect of glue, thiourea, and chloride additions to the bath on cathodic copper was examined. Electrolysis conditions, in accordance with industrial practice, kept constant in both sets of experiments and were as follows: 45 g Cu 2+/L, 150 g H2SO4/L, 55C, electrolyte circulation of 15-20 L/min, anode dimensions of 78 74 4.5 mm, copper cathode of 47 85x0.1 mm, current density of 700 A/m2, and the aforesaid additives. Lab-scale high current density copper rening electrolysis was carried out in a specially designed cell with a unique elect...
The aim of this study is to investigate the utility of adding chelating agent during hydrochloric... more The aim of this study is to investigate the utility of adding chelating agent during hydrochloric acid leaching of low-grade scheelite concentrates, obtained from Uluda , Bursa (Türkiye). Examined parameters were as follows; leaching conditions, selective precipitation of tungsten salt ...
International Journal of Mineral Processing and Extractive Metallurgy
The consumption of mobile phones is increasing day by day and the replacement speed is also accel... more The consumption of mobile phones is increasing day by day and the replacement speed is also accelerating. Thus, a lot of old mobile phones and their parts need to be processed. Mobile phones contain more than 40 elements and/or materials. This experimental study aims to establish the possibilities of recovering valuable metals from waste mobile phones by using acidic leaching. The process steps include dismantling of waste mobile phones, pre-processing to liberate the materials, and directing them to final treatment processes. Prior to leaching tests, the PCBs of waste mobile phone sample are chemically analyzed and its metal contents are found as 33.22% Cu, 9.42% Fe, 1.86% Zn, 2.77% Ni, 1.63% Al, 0.4% Pb, 0.02% Co, 0.14% Ag, and 251.2 ppm Au. In the leaching experiments, sulfuric, nitric, and hydrochloric acids are used. In the sulfuric acid leaching experiments, effects of acid concentration, temperature, hydrogen peroxide addition, and leaching periods on metal dissolution efficiencies are investigated. Results are compared and discussed in relation to the types of acids. XRD analyses of feed material and leach residues are also carried out. As a result of this experimental study, 97.9% Fe leaching in 8 M H 2 SO 4 solutions, 89% Pb, 100% Ni, 90.4% Co, and 4.1% Cu leaching in 1M HNO 3 solutions, 100% Pb, and 100% Al leaching in 4 M HCl solutions in one hour are found. In conclusion, sequential leaching with different acids is recommended for the effective leaching of all metals.
The hydrometallurgical route of zinc hydroxide and synthesis of nanocrystalline ZnO is a particul... more The hydrometallurgical route of zinc hydroxide and synthesis of nanocrystalline ZnO is a particularly attractive method to recover oxidized lead and zinc from lead-zinc flotation tailings. In Turkey, lead-zinc complex/mixed ores along with high iron content are not suitable for conventional mineral processing methods and need hydrometallurgical treatments. Therefore, the control of iron during zinc processes is really important. In this study, hydrometallurgical process route for zinc recovery from Pb-Zn flotation tailings was investigated by considering the effects of H2SO4 concentration, leaching and roasting temperatures on the zinc dissolution considering the Eh-pH variations. The iron and zinc products were also individually examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images in order to compare before and after leaching, precipitation and roasting steps. 83.1% Zn and 91.6% Cd leaching efficiencies were obtained from ...
Journal of Nanoelectronics and Optoelectronics, 2020
ZnO nanowire arrays were fabricated by hydrothermal growth on Al-doped ZnO (ZnO:Al) seed layers c... more ZnO nanowire arrays were fabricated by hydrothermal growth on Al-doped ZnO (ZnO:Al) seed layers coated on soda-lime silicate glass by sol–gel coating. The properties of the ZnO:Al seed layer were evaluated to obtain ZnO nanowires with the optimal size and length and to realize suitable adhesion of the ZnO:Al grains to the substrate. The optimal mechanical performance (adhesion and abrasion resistance) of the ZnO:Al seed layer was obtained at Al 1 at.%. The seed layers annealed between 400 and 500 C exhibited enhanced ZnO nanowire growth. Increasing the annealing temperature within this range improved the electrical and optical properties of the nanowires. Additionally, two chemical compounds, zinc acetate (ZA) and zinc nitrate (ZN), were used to compare the effects of the solution type on the hydrothermal growth. The nanowires grown in the ZA solution were thicker and had higher electrical conductivity compared to the ZN solution. The gamma transmission technique was used to determi...
Two electrochemical reactions proceed simultaneously at the anode: the evolution of oxygen and th... more Two electrochemical reactions proceed simultaneously at the anode: the evolution of oxygen and the oxidation of Cr(III) to Cr(VI). The Cr(VI) diffuses from the anode compartment through the diaphragm, and it reacts with Cr(II) in the catholyte. Since the current efficiency for ...
The hydrometallurgical treatment of zinc sulfide concentrates involves the separation of zinc fro... more The hydrometallurgical treatment of zinc sulfide concentrates involves the separation of zinc from iron, since most zinc concentrates contain 5-12% iron. Several processes, such as hematite, magnetite, goethite and jarosite, have been developed for the removal of iron ...
Material Science & Engineering International Journal
In this study, solvent extraction is applied for extracting nickel from sulfate solutions contain... more In this study, solvent extraction is applied for extracting nickel from sulfate solutions containing iron and cobalt ions. This process can also be applied for the cleaning of waste solutions and for increasing solution concentrations after the leaching of low-grade nickel ores. Di-2-Ethylhexyl phosphoric acid (D2EHPA) was used as an extractant for this purpose. Effects of pH, aqueous/organic (A/O) phase ratio, iron, and cobalt ion contents of the solution on nickel extraction efficiency were investigated. The McCabe-Thiele diagrams for extraction and stripping steps were developed to determine the number of stages required. A total of two stages were required for 96.3% of Ni extraction and a total of two stages to strip nickel with 98% efficiency.
The possibility of producing metallic chromium from Cr2O3 via the aluminothermic route, with no e... more The possibility of producing metallic chromium from Cr2O3 via the aluminothermic route, with no external energy supply, was the subject of this laboratory-scale research. The experimental study focused on investigating the individual effects and quantitative optimization of the charge contents, i.e., the additions of CrO3, Al powder and CaO (or BaO). The highest chromium recovery of 98% was attained with the additions of 12% CrO3 and 1.2 times the stoichiometric ally required amount of Al powder. The optimum CaO addition giving the highest chromium recovery was found when the CaO/Al weight ratio in the charge was equal to 0.3. When BaO was used, however, 95% Cr extraction efficiency was obtained at a BaO/Al weight ratio ofO. 15.
For the worldwide steel production of 725 Mt in 1993, 503 Mt of hot metal, 24 Mt of sponge iron, ... more For the worldwide steel production of 725 Mt in 1993, 503 Mt of hot metal, 24 Mt of sponge iron, and about 400 Mt of scrap were used. Today, the share of electric arc furnaces in this steel production is about 30%, meaning that every third ton of the steel produced worldwide is made by recycled scrap. This percentage is even higher in Turkey where two-thirds of the steel produced is manufactured from scrap. Although no major increase in steel production is anticipated in the near future, any that does occur will be via electric arc furnaces, which will increase the demand for scrap. In the future, a decrease in the amount of circulating scrap and a slight increase in process scrap are expected ; thus, the increased demand for scrap will be balanced mostly by the capital scrap. These developments might cause a drop in the quality of scrap. Many problems have to be solved in the future with scrap processing and recycling. This must be achieved by cooperation between the steel producin...
In this study, strontium carbonate precipitation from strontium sulphide solution was investigate... more In this study, strontium carbonate precipitation from strontium sulphide solution was investigated. Experimental study was carried out to determine the effects of precipitation period (5, 15, 30, 60 min), sodium carbonate concentration (1, 1.1, 1.25, 1.5, and 2M) and temperature (25, 55, 75°C). The SrS solution used in the experiments was obtained by dissolving the black ash produced by our previous work in pure water. The concentration of Sr was determined to be 22.23 g/L by AAS analysis. The XRD results showed that the solid was SrCO3. The intensity of XRD peaks increased with increasing temperature. The effect of precipitation period for efficiency is too low to be taken into account. As the sodium carbonate concentration increased, SrCO3 precipitation yield increased. Finally, AAS analysis showed that maximum recovery was obtained as 97.1% Sr under the conditions of 2 M Na2CO3, 75°C, 60 min.
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