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Nele De Belie - One of the best experts on this subject based on the ideXlab platform.
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influence of intensive vacuum mixing and heat treatment on compressive strength and microstructure of reactive powder concrete incorporating secondary Copper Slag as supplementary cementitious material
2017Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Nele De BelieAbstract:Abstract In this study the effect of vacuum mixing and heat treatment on the compressive strength and microstructure of reactive powder concrete (RPC), made with secondary Copper Slag as partial cement replacement is investigated. The quickly cooled granulated Copper Slag was ground using a planetary ball mill. A low water-to-binder ratio of 0.185 was chosen. The series of concrete mixtures and cement paste samples were produced with Copper Slag contents from 0 to 20 wt%. The pozzolanic activity of Slag was determined by the Frattini test. The performance of RPC mixed under vacuum conditions and heat-cured was compared to that of RPC mixed at atmospheric pressure without heat treatment. The porosity evolution of RPC was investigated by mercury intrusion porosimetry. A higher workability of the fresh RPC was obtained by mixing under atmospheric pressure. The presence of Copper Slag in the RPC had no adverse effect on compressive strength for all treatments. The heat treatment decreases the porosity and enhances the RPC strength. Assessment of the pozzolanic activity by means of the Frattini test indicates low pozzolanic reaction of the Slag after 15 days. The presence of Slag in the paste tends to decrease the total heat production of the paste. The use of Copper Slag as cement replacement in the RPC production decreases the energy consumption and reduces the carbon footprint.
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influence of vacuum mixing on the carbonation resistance and microstructure of reactive powder concrete containing secondary Copper Slag as supplementary cementitious material scm
2017Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Jeroen Dils, Nele De BelieAbstract:Abstract This study aims to examine the effect of vacuum mixing on the carbonation resistance and microstructure of reactive powder concrete (RPC), made with secondary Copper Slag as partial cement replacement. In order to obtain a homogenous mixture, a high speed mixer with vacuum was applied. Accelerated carbonation tests (10% CO 2 , 20 °C and 60% RH) were performed on RPC, mixed under vacuum conditions, as a comparison to RPC mixed at atmospheric pressure. The evolution of the carbonation depth was determined by spraying phenolphthalein on a freshly split RPC surface at varying ages (1 to 16 weeks). The microstructure of RPC was investigated by a mercury intrusion porosimeter (MIP). The pozzolanic activity of QCS was determined by the Chapelle test, taking into account the carbonation effect on the reference system. The results obtained, showed that no carbonation was detected after 90 days for the RPC containing Copper Slag both under vacuum condition and atmospheric pressure. The presence of Copper Slag in the RPC tends to increase the porosity reduction and decrease the strength enhancement when applying vacuum mixing to the mixture. The result of the Chapelle test indicated that the secondary Copper Slag did not tend to consume much portlandite.
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effect of secondary Copper Slag as cementitious material in ultra high performance mortar
2016Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Mieke De Schepper, Nele De BelieAbstract:Abstract This research investigates the use of Copper Slag as supplementary cementitious material (SCM) in ultra high performance mortar (UHPM). Two secondary Slag types from a plant in Belgium were utilized as SCM and were classified as a quickly cooled granulated Copper Slag (QCS) and a slowly cooled broken Copper Slag (SCS). Both materials were ground intensively using a planetary ball mill. A low water-to-binder ratio of 0.15 was chosen for the UHPM in this study. Various mortar and cement paste samples were produced with increasing Copper Slag content from 0 to 20 wt% in steps of 5 wt%. Particle size distribution (PSD) and specific surface area (SSA) of the Copper Slag were assessed using laser diffraction and the Blaine permeability test. The pozzolanic activity of Copper Slag was evaluated using the Chapelle test, strength activity index (SAI) and Frattini test. The results obtained, showed that the strength of mortars with different Copper Slag proportions was comparable to or even better than the control mixture at 90 days. The increased fineness of the Copper Slag enhances the mortar strength. Using isothermal calorimetry, it was found that the addition of Copper Slag slows down the hydration of the cement pastes. The rate of pozzolanic activity of Copper Slag depends on temperature, curing age, and particle sizes.
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effect of Copper Slag as supplementary cementitious material scm in ultra high performance mortar uhpm
2015Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Mieke De Schepper, Nele De BelieAbstract:This research investigates the use of Copper Slag as supplementary cementitious materials (SCM) in ultra high performance mortar (IHPM). Two secondary Slag types from a plant in Belgium were utilized as SCM and were classified as a quickly cooled granulated Copper Slag (QCS) and a slowly cooled broken Copper Slag (SCS). Both materials were ground intensively using a planetary ball mill. A low water-to-binder ratio of 0.15 was chosen for the UHPM in this study. Various mortar and cement paste samples were produced with increasing Copper Slag content from 0 to 20 wt% in steps of 5 wt%. Particle size distribution (PSD) and specific surface area (SSA) of the Copper Slag were assessed using laser diffraction and the Blaine permeability test, respectively. The results obtained, showed that the strength of mortars with different Copper Slag proportions was comparable to or even better than the control mixture at 90 days. The increased fineness of the Copper Slag enhances the mortar strength. Using isothermal calorimetry it was found that the addition of Copper Slag slows down the hydration of the cement pastes.
Rizwan Ahmad Khan - One of the best experts on this subject based on the ideXlab platform.
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Carbonation Resistance of Self-Compacting Concrete Incorporating Copper Slag as Fine Aggregates
2020Co-Authors: Rahul Sharma, Rizwan Ahmad KhanAbstract:AbstractThe aim of present investigation is to evaluate the carbonation resistance of self-compacting concrete (SCC) containing Copper Slag (CS) as fine aggregates. A total of 18 mixes were prepare...
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Influence of Copper Slag and Metakaolin on the Durability of Self Compacting Concrete
2018Co-Authors: Rahul Sharma, Rizwan Ahmad KhanAbstract:Abstract Now-a-days, researchers are endeavoring to discover new substitute materials to elucidate the scarcity of natural aggregates in the construction industry. One such alternative is Copper Slag (CS) obtained as byproduct during the matte smelting process of Copper metal. The present investigation is aimed to assess the durability of self compacting concrete (SCC) incorporating Copper Slag (CS) as fine aggregates and metakaolin (MK) as substitute to fly ash (FA). A total of seven concrete mixes were prepared. The control concrete contains 60% ordinary portland cement (OPC), 40% FA and 0% CS whereas other six mixes contains constant percentage of 60% OPC, 30% FA, 10% MK with different proportions of CS from 0% to 100%. Results revealed that fresh properties declined with inclusion of MK although escalated with increment of CS content. All SCC mixes exhibited higher compressive and splitting tensile strength in comparison to control concrete. The minimum carbonation depth was marked for 100% CS substitution with 10% MK as replacement to FA. The maximum electrical resistivity and resistance to sulfate attack were obtained for 20% CS substitution while UPV values of whole mixes were under the excellent quality of concrete beyond 7 days of curing. On full replacement of sand by CS with 10% MK, initial surface absorption and sorptivity were significantly lower than control concrete at each curing period. This study suggests that CS together with MK can be a potential substitute to natural sand in the construction sector to overcome the scarcity.
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durability assessment of self compacting concrete incorporating Copper Slag as fine aggregates
2017Co-Authors: Rahul Sharma, Rizwan Ahmad KhanAbstract:Abstract The present study intends to evaluate the durability of Self Compacting Concrete (SCC) containing Copper Slag as fine aggregates. A total of six SCC mixes were cast with 0%, 20%, 40%, 60%, 80% and 100% Copper Slag substitution at constant w/b ratio of 0.45. The various tests conducted on SCC mixes included fresh properties, compressive strength, sulfate attack, accelerated carbonation, electrical resistivity, ultrasonic pulse velocity, initial surface absorption and sorptivity. Results showed that fresh properties enhanced with increment in Copper Slag substitution. The maximum compressive strength was noticed for 20% Copper Slag. In sulfate exposure, gain in weight and decrease in compressive strength was observed for concrete mixes. Incorporation of Copper Slag has significant effect in the reduction of carbonation. The benefit of utilizing Copper Slag in construction industry bestows as substitute to fine aggregates, preserves natural resources and no land management for disposal of Copper Slag. This study suggests that 60% Copper Slag is an optimum content as partial replacement to conventional sand for either enhanced or comparable durability behavior of SCC.
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sustainable use of Copper Slag in self compacting concrete containing supplementary cementitious materials
2017Co-Authors: Rahul Sharma, Rizwan Ahmad KhanAbstract:Abstract Copper Slag (CS) is an industrial by-product obtained in bulk quantity during matte smelting and refining process of Copper metal. The current research is aimed to investigate the sustainable utilisation of CS as fine aggregates in Self Compacting Concrete (SCC) using fly ash (FA) and silica fume (SF) as Supplementary Cementitious Materials (SCMs). Total seven concrete mixes were cast in which one mix was binary blend containing 60% ordinary portland cement (OPC), 40% FA and 0% SF with 100% sand and 0% CS as control concrete. The other six mixes were ternary blends containing 60% OPC, 30% FA and 10% SF with 0, 20, 40, 60, 80 and 100% CS substitution. The fresh properties of SCC mixes were found to be escalating up to 100% CS substitution. The maximum improvements in compressive and splitting tensile strength with respect to control were obtained as 20% and 60% CS substitution. Ultrasonic pulse velocity of all ternary SCC mixes was found to be increased, whereas initial surface absorption and sorptivity reduced in comparison to control concrete. The results of scanning electron microscopy and energy dispersive spectroscopy illustrate the formation of uniformly distributed and compact C-S-H gel in presence of CS after 120 d, with Ca/Si ratio ranging between 0.77 and 1.11. The SCC mix with 100% CS substitution was found to be most economical with least consumption of embodied energy and emission of embodied carbon dioxide. This study authenticates that CS in combination with SCMs is promising alternative over the conventional sand in construction industry.
Romy Suryaningrat Edwin - One of the best experts on this subject based on the ideXlab platform.
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influence of intensive vacuum mixing and heat treatment on compressive strength and microstructure of reactive powder concrete incorporating secondary Copper Slag as supplementary cementitious material
2017Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Nele De BelieAbstract:Abstract In this study the effect of vacuum mixing and heat treatment on the compressive strength and microstructure of reactive powder concrete (RPC), made with secondary Copper Slag as partial cement replacement is investigated. The quickly cooled granulated Copper Slag was ground using a planetary ball mill. A low water-to-binder ratio of 0.185 was chosen. The series of concrete mixtures and cement paste samples were produced with Copper Slag contents from 0 to 20 wt%. The pozzolanic activity of Slag was determined by the Frattini test. The performance of RPC mixed under vacuum conditions and heat-cured was compared to that of RPC mixed at atmospheric pressure without heat treatment. The porosity evolution of RPC was investigated by mercury intrusion porosimetry. A higher workability of the fresh RPC was obtained by mixing under atmospheric pressure. The presence of Copper Slag in the RPC had no adverse effect on compressive strength for all treatments. The heat treatment decreases the porosity and enhances the RPC strength. Assessment of the pozzolanic activity by means of the Frattini test indicates low pozzolanic reaction of the Slag after 15 days. The presence of Slag in the paste tends to decrease the total heat production of the paste. The use of Copper Slag as cement replacement in the RPC production decreases the energy consumption and reduces the carbon footprint.
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influence of vacuum mixing on the carbonation resistance and microstructure of reactive powder concrete containing secondary Copper Slag as supplementary cementitious material scm
2017Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Jeroen Dils, Nele De BelieAbstract:Abstract This study aims to examine the effect of vacuum mixing on the carbonation resistance and microstructure of reactive powder concrete (RPC), made with secondary Copper Slag as partial cement replacement. In order to obtain a homogenous mixture, a high speed mixer with vacuum was applied. Accelerated carbonation tests (10% CO 2 , 20 °C and 60% RH) were performed on RPC, mixed under vacuum conditions, as a comparison to RPC mixed at atmospheric pressure. The evolution of the carbonation depth was determined by spraying phenolphthalein on a freshly split RPC surface at varying ages (1 to 16 weeks). The microstructure of RPC was investigated by a mercury intrusion porosimeter (MIP). The pozzolanic activity of QCS was determined by the Chapelle test, taking into account the carbonation effect on the reference system. The results obtained, showed that no carbonation was detected after 90 days for the RPC containing Copper Slag both under vacuum condition and atmospheric pressure. The presence of Copper Slag in the RPC tends to increase the porosity reduction and decrease the strength enhancement when applying vacuum mixing to the mixture. The result of the Chapelle test indicated that the secondary Copper Slag did not tend to consume much portlandite.
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effect of secondary Copper Slag as cementitious material in ultra high performance mortar
2016Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Mieke De Schepper, Nele De BelieAbstract:Abstract This research investigates the use of Copper Slag as supplementary cementitious material (SCM) in ultra high performance mortar (UHPM). Two secondary Slag types from a plant in Belgium were utilized as SCM and were classified as a quickly cooled granulated Copper Slag (QCS) and a slowly cooled broken Copper Slag (SCS). Both materials were ground intensively using a planetary ball mill. A low water-to-binder ratio of 0.15 was chosen for the UHPM in this study. Various mortar and cement paste samples were produced with increasing Copper Slag content from 0 to 20 wt% in steps of 5 wt%. Particle size distribution (PSD) and specific surface area (SSA) of the Copper Slag were assessed using laser diffraction and the Blaine permeability test. The pozzolanic activity of Copper Slag was evaluated using the Chapelle test, strength activity index (SAI) and Frattini test. The results obtained, showed that the strength of mortars with different Copper Slag proportions was comparable to or even better than the control mixture at 90 days. The increased fineness of the Copper Slag enhances the mortar strength. Using isothermal calorimetry, it was found that the addition of Copper Slag slows down the hydration of the cement pastes. The rate of pozzolanic activity of Copper Slag depends on temperature, curing age, and particle sizes.
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effect of Copper Slag as supplementary cementitious material scm in ultra high performance mortar uhpm
2015Co-Authors: Romy Suryaningrat Edwin, Elke Gruyaert, Mieke De Schepper, Nele De BelieAbstract:This research investigates the use of Copper Slag as supplementary cementitious materials (SCM) in ultra high performance mortar (IHPM). Two secondary Slag types from a plant in Belgium were utilized as SCM and were classified as a quickly cooled granulated Copper Slag (QCS) and a slowly cooled broken Copper Slag (SCS). Both materials were ground intensively using a planetary ball mill. A low water-to-binder ratio of 0.15 was chosen for the UHPM in this study. Various mortar and cement paste samples were produced with increasing Copper Slag content from 0 to 20 wt% in steps of 5 wt%. Particle size distribution (PSD) and specific surface area (SSA) of the Copper Slag were assessed using laser diffraction and the Blaine permeability test, respectively. The results obtained, showed that the strength of mortars with different Copper Slag proportions was comparable to or even better than the control mixture at 90 days. The increased fineness of the Copper Slag enhances the mortar strength. Using isothermal calorimetry it was found that the addition of Copper Slag slows down the hydration of the cement pastes.
Zhengqi Guo - One of the best experts on this subject based on the ideXlab platform.
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a novel process to upgrade the Copper Slag by direct reduction magnetic separation with the addition of na2co3 and cao
2019Co-Authors: Jian Pan, Deqing Zhu, Zhengqi Guo, Jianlei ChouAbstract:Abstract An innovative technology for direct reduction-magnetic separation with the addition of Na2CO3 and CaO was studied to upgrade Copper Slag assaying 40.33% Fetotal and 0.65% Cu. It is difficult to recover iron and Copper from the Slag by direct reduction since the iron mainly occurs in fayalite and the Copper exists in Copper sulfide. Additives such as Na2CO3 and CaO has been proven to be capable of reinforcing the reduction of refractory iron ore in many papers. In this study, the effect of Na2CO3 dosage and binary basicity (CaO/SiO2) on the coal-based reduction of Copper Slag was investigated. The results show that the addition of CaO at 0.5 basicity and 8% sodium carbonate, the recovery of the iron and Copper can be significantly improved to 94.3% and 86.5%, respectively. Meanwhile, the iron and Copper content of magnetic concentrate are maintained at 90.5% and 1.2%, respectively, which can be used as burden for smelting of weathering steel, and the nonmagnetic tailings obtained in this process can be applied as raw materials in cement and industry, and the dust collected from the direct reduction process contains 50.65% Zn and 8.56% Pb at a recovery of 99.16% and 91.89%, and can be used as feed for extraction of Zn and Pb.
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green and efficient utilization of waste ferric oxide desulfurizer to clean waste Copper Slag by the smelting reduction sulfurizing process
2018Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:Abstract This research proposed an efficient, innovative and environmentally friendly technology named smelting reduction-sulfurizing process, which uses one waste (waste ferric-oxide desulfurizer) to treat another (waste Copper Slag). In the new process, the waste ferric-oxide desulfurizer was employed not only as a sulfurizing agent to sulfurize and collect the Copper lost in Copper Slag, but also as a reductant to reduce the magnetite to “FeO” and thus improve Slag fluidity. It was revealed that 90.81% Cu was recovered and enriched in Copper matte under the smelting conditions. The matte contained 15.87% Copper, 20.25% S and 49.56% Fe, which can be returned to the Copper smelting process as a feeding. Meanwhile, the removal rate of hazardous elements, such as Ni, Pb, Zn, As, Sb, Bi and Hg, from the initial Copper Slag by the new process was also determined, and the elimination rate of those elements was all over 90%.The leaching toxicity was used to further evaluate the environmental impact of the cleaned Slag, indicating that the concentrations of toxic element ions in the leachate are all much lower than the thresholds, which confirmed that the cleaned Slag with trace toxic elements is safe and harmless.
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innovative methodology for comprehensive and harmless utilization of waste Copper Slag via selective reduction magnetic separation process
2018Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:Abstract It is very difficult to extract valuable metals from Copper Slag and nickel laterite through traditional separation processes due to their complex mineral structure. In this work, a selective co-reduction and magnetic separation process was developed to economically and eco-friendly clean Copper Slag and synchronously upgrade nickel laterite. Through the innovative process, not only the valuable metals, such as Fe, Ni and Cu, can be recovered, but also the hazardous elements can be removed from Copper Slag, including As, Pb and Zn. Under optimum conditions, a crud Fe-Ni-Cu alloy assaying 2.51% Ni,1.07%Cu and 87.94% Fe can be manufactured as feed for producing weathering steel, and the corresponding recoveries of Ni, Cu and Fe were 87.15%, 79.68% and 68.96%, respectively. The final tailings containing less toxic elements can be used as raw materials for cement. The mechanism of co-reduction of Copper Slag and nickel laterite was revealed by XRD, SEM-EDS and EPMA techniques. The results show that a suitable proportion of Copper Slag and nickel laterite was essential to acquire appropriate amount of liquid phase, thereby improve metallic alloy particles migration and growth, which will significantly increase metal recovery in magnetic separation. The leaching toxicity was used to characterize the environmental impact of tailings obtained by co-reduction and magnetic separation process.
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mechanism of mineral phase reconstruction for improving the beneficiation of Copper and iron from Copper Slag
2016Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:To maximize the recovery of iron and Copper from Copper Slag, the modification process by adding a compound additive (a mixture of hematite, pyrite and manganous oxide) and optimizing the cooling of the Slag was studied. The phase reconstruction mechanism of the Slag modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that the synergy between the burnt lime and the compound additive promotes the generation of target minerals, such as magnetite and Copper matte. In addition, the multifunctional compound additive is able to improve the fluidity of the molten Slag, which facilitates the coalescence and growth of fine particles of the target minerals. As a result, the percentage of iron distributed in the form of magnetite increased from 32.9% to 65.1%, and that of the Copper exiting in the form of metallic Copper and Copper sulfide simultaneously increased from 80.0% to 90.3%. Meanwhile, the grains of the target minerals in the modified Slag grew markedly to a mean size of over 50 μm after slow cooling. Ultimately, the beneficiation efficiency of Copper and iron was improved because of the ease with which the target minerals could be liberated.
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improving beneficiation of Copper and iron from Copper Slag by modifying the molten Copper Slag
2016Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:In the paper, a new technology was developed to improve the beneficiation of Copper and iron components from Copper Slag, by modifying the molten Slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS) was employed to determine the mineralogy of the modified and unmodified Slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the Copper grade of rougher Copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified Copper Slag. Moreover, matte and magnetite grains in the modified Slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of Copper and iron.
Feng Zhang - One of the best experts on this subject based on the ideXlab platform.
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green and efficient utilization of waste ferric oxide desulfurizer to clean waste Copper Slag by the smelting reduction sulfurizing process
2018Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:Abstract This research proposed an efficient, innovative and environmentally friendly technology named smelting reduction-sulfurizing process, which uses one waste (waste ferric-oxide desulfurizer) to treat another (waste Copper Slag). In the new process, the waste ferric-oxide desulfurizer was employed not only as a sulfurizing agent to sulfurize and collect the Copper lost in Copper Slag, but also as a reductant to reduce the magnetite to “FeO” and thus improve Slag fluidity. It was revealed that 90.81% Cu was recovered and enriched in Copper matte under the smelting conditions. The matte contained 15.87% Copper, 20.25% S and 49.56% Fe, which can be returned to the Copper smelting process as a feeding. Meanwhile, the removal rate of hazardous elements, such as Ni, Pb, Zn, As, Sb, Bi and Hg, from the initial Copper Slag by the new process was also determined, and the elimination rate of those elements was all over 90%.The leaching toxicity was used to further evaluate the environmental impact of the cleaned Slag, indicating that the concentrations of toxic element ions in the leachate are all much lower than the thresholds, which confirmed that the cleaned Slag with trace toxic elements is safe and harmless.
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innovative methodology for comprehensive and harmless utilization of waste Copper Slag via selective reduction magnetic separation process
2018Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:Abstract It is very difficult to extract valuable metals from Copper Slag and nickel laterite through traditional separation processes due to their complex mineral structure. In this work, a selective co-reduction and magnetic separation process was developed to economically and eco-friendly clean Copper Slag and synchronously upgrade nickel laterite. Through the innovative process, not only the valuable metals, such as Fe, Ni and Cu, can be recovered, but also the hazardous elements can be removed from Copper Slag, including As, Pb and Zn. Under optimum conditions, a crud Fe-Ni-Cu alloy assaying 2.51% Ni,1.07%Cu and 87.94% Fe can be manufactured as feed for producing weathering steel, and the corresponding recoveries of Ni, Cu and Fe were 87.15%, 79.68% and 68.96%, respectively. The final tailings containing less toxic elements can be used as raw materials for cement. The mechanism of co-reduction of Copper Slag and nickel laterite was revealed by XRD, SEM-EDS and EPMA techniques. The results show that a suitable proportion of Copper Slag and nickel laterite was essential to acquire appropriate amount of liquid phase, thereby improve metallic alloy particles migration and growth, which will significantly increase metal recovery in magnetic separation. The leaching toxicity was used to characterize the environmental impact of tailings obtained by co-reduction and magnetic separation process.
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mechanism of mineral phase reconstruction for improving the beneficiation of Copper and iron from Copper Slag
2016Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:To maximize the recovery of iron and Copper from Copper Slag, the modification process by adding a compound additive (a mixture of hematite, pyrite and manganous oxide) and optimizing the cooling of the Slag was studied. The phase reconstruction mechanism of the Slag modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that the synergy between the burnt lime and the compound additive promotes the generation of target minerals, such as magnetite and Copper matte. In addition, the multifunctional compound additive is able to improve the fluidity of the molten Slag, which facilitates the coalescence and growth of fine particles of the target minerals. As a result, the percentage of iron distributed in the form of magnetite increased from 32.9% to 65.1%, and that of the Copper exiting in the form of metallic Copper and Copper sulfide simultaneously increased from 80.0% to 90.3%. Meanwhile, the grains of the target minerals in the modified Slag grew markedly to a mean size of over 50 μm after slow cooling. Ultimately, the beneficiation efficiency of Copper and iron was improved because of the ease with which the target minerals could be liberated.
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improving beneficiation of Copper and iron from Copper Slag by modifying the molten Copper Slag
2016Co-Authors: Zhengqi Guo, Deqing Zhu, Jian Pan, Feng ZhangAbstract:In the paper, a new technology was developed to improve the beneficiation of Copper and iron components from Copper Slag, by modifying the molten Slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS) was employed to determine the mineralogy of the modified and unmodified Slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the Copper grade of rougher Copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified Copper Slag. Moreover, matte and magnetite grains in the modified Slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of Copper and iron.