In comparison with copper processing industrial leader Furukawa Electric Co., Ltd., Chinese copper processing industry faces many shortcomings and difficulties including but not limited to outdated equipment and techn...In comparison with copper processing industrial leader Furukawa Electric Co., Ltd., Chinese copper processing industry faces many shortcomings and difficulties including but not limited to outdated equipment and technologies, low degree of specialization, and unstable product quality. The review of Furukawa Electric’s development milestones reveals that Chinese copper processing industry has reached a stage in which it must rely on technological research and development (R & D) to promote sustainable productivity. Chinese copper processing firms have to invest in R & D to promote sustainable technological innovations and to improve the precisions of business practice in order to ensure the firms’ improvement.展开更多
Microstructural development of ultra low C, N, Fe-Cr alloy and pure copper processed by equal-channel angular pressing (ECAP) have been examined focusing on the initial stage of the formation of ultrafine grain struct...Microstructural development of ultra low C, N, Fe-Cr alloy and pure copper processed by equal-channel angular pressing (ECAP) have been examined focusing on the initial stage of the formation of ultrafine grain structure. Fe-Cr alloys were pressed at 423 K while pure copper at room temperature for 1 to 3 passes via the route Bc to compare at the equivalent homologous temperature. Microstructural evolutions were characterized by electron backscatter diffraction (EBSD) image and transmission electron microscopy (TEM). It was found that deformation structures were mostly deformation-induced subboundaries in both the materials after one pass, but the fraction of high-angle grain boundary became higher in the Fe-Cr alloys than in pure copper in subsequent passes by increasing misorientation of the boundaries. The more enhanced formation of high angle boundaries in Fe-Cr alloys was discussed in terms of the nature of crystal slip of FCC and BCC structures.展开更多
Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation indust...Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation industrial processes.This paper addresses the fluctuation problem of CCG through an operational optimization method.Firstly,a density-based affinity propagationalgorithm is proposed so that more ideal working condition categories can be obtained for the complex raw ore properties.Next,a Bayesian network(BN)is applied to explore the relationship between the operational variables and the CCG.Based on the analysis results of BN,a weighted Gaussian process regression model is constructed to predict the CCG that a higher prediction accuracy can be obtained.To ensure the predicted CCG is close to the set value with a smaller magnitude of the operation adjustments and a smaller uncertainty of the prediction results,an index-oriented adaptive differential evolution(IOADE)algorithm is proposed,and the convergence performance of IOADE is superior to the traditional differential evolution and adaptive differential evolution methods.Finally,the effectiveness and feasibility of the proposed methods are verified by the experiments on a copper flotation industrial process.展开更多
China is the world’s largest producer of copper processing products as well as the world’s largest copper consumer market.In 2013,China produced more than 13.60 million tons of copper processing products,accounting ...China is the world’s largest producer of copper processing products as well as the world’s largest copper consumer market.In 2013,China produced more than 13.60 million tons of copper processing products,accounting for60%of the world’s total production.Since then,this proportion has expanded year by year,and will increase to about 66.7%in 2016.Meanwhile,China consumed nearly 11展开更多
Tongling Nonferrous Metals Group Holdings Co.,Ltd.(referred to as Tongling Nonferrous)was profitable as for its copper processing sector in 2015.In 2017,its achievements continued by making historic breakthroughs:Tong...Tongling Nonferrous Metals Group Holdings Co.,Ltd.(referred to as Tongling Nonferrous)was profitable as for its copper processing sector in 2015.In 2017,its achievements continued by making historic breakthroughs:Tongguan Copper Foil Company realized a YOY growth of 208.63%;Tongguan Copper Product Branch has been making展开更多
On May 15,the Southwestern Copper Production Base invested by Zhejiang Hailiang Co.,Ltd.,the world’s largest copper processing company,started construction in Luohuang Industrial Park,Jiangjin District.With a total i...On May 15,the Southwestern Copper Production Base invested by Zhejiang Hailiang Co.,Ltd.,the world’s largest copper processing company,started construction in Luohuang Industrial Park,Jiangjin District.With a total investment of 3 billion yuan,the annual output value at maximum production capacity展开更多
The effects of the concentration of Lix 984N,phase ratio,initial pH value of aqueous phase and extraction time on the extraction of copper and iron under the condition of low Cu2+ /Fe3+ ratio in dump bioleaching solut...The effects of the concentration of Lix 984N,phase ratio,initial pH value of aqueous phase and extraction time on the extraction of copper and iron under the condition of low Cu2+ /Fe3+ ratio in dump bioleaching solution of Dexing Copper Mine were explored.The optimal conditions of extraction are as follows: the concentration of Lix 984N 10%; the phase ratio (O/A) 1:1; the initial pH value of aqueous phase 1.5 and the mixing time 2 min.The stripping experiments show that H2SO4 solution could efficiently recover copper from the organic phase under the optimal conditions.展开更多
Systematic physical simulation of thermo-mechanical processing routes has been ap-plied on a Gleeble 1500 simulator to four copper alloys (mass %) Cu-0.57Co-0.32Si,Cu-0.55Cr-0.065P, Cu-0.22Zr-0.035Si and Cu-1.01Ni-0.4...Systematic physical simulation of thermo-mechanical processing routes has been ap-plied on a Gleeble 1500 simulator to four copper alloys (mass %) Cu-0.57Co-0.32Si,Cu-0.55Cr-0.065P, Cu-0.22Zr-0.035Si and Cu-1.01Ni-0.43Si aimed at clarifying theinfluences of processing conditions on their final properties, strength and electricalconductivity. Flow curves were determined over wide temperature and strain rateranges. Hardness was used as a measure of the strength level achieved. High hard-ness was obtained as using equal amounts (strains 0.5) of cold deformation beforeand after the precipitation annealing stage. The maximum values achieved for theCu-Co-Si, Cu-Cr-P, Cu-Zr-Si and Cu-Ni-Si alloys were 190, 165, 178 and 193 HV5,respectively. A thermo-mechanical schedule involving the hot deformation-ageing-colddeformation stages showed even better results for the Cu-Zr-Si alloy. Consequently,the processing routes were designed based on simulation test results and wires of 5 and2mm in diameters have been successfully processed in the industrial scale.展开更多
Due to the importance of detecting the matte grade in the copper flash smelting process, the mechanism model was established according to the multi-phase and multi-component mathematic model. Meanwhile this procedure ...Due to the importance of detecting the matte grade in the copper flash smelting process, the mechanism model was established according to the multi-phase and multi-component mathematic model. Meanwhile this procedure was a complicated production process with characteristics of large time delay, nonlinearity and so on. A fuzzy neural network model was set up through a great deal of production data. Besides a novel constrained gradient descent algorithm used to update the parameters was put forward to improve the parameters learning efficiency. Ultimately the self-adaptive combination technology was adopted to paralleled integrate two models in order to obtain the prediction model of the matte grade. Industrial data validation shows that the intelligently integrated model is more precise than a single model. It can not only predict the matte grade exactly but also provide optimal control of the copper flash smelting process with potent guidance.展开更多
The aging hardening process makes it possible to get higher hardness and electrical conductivity of lead frame copper alloy. The process has only been studied empirically by trial-and-error method so far. The use of a...The aging hardening process makes it possible to get higher hardness and electrical conductivity of lead frame copper alloy. The process has only been studied empirically by trial-and-error method so far. The use of a supervised artificial neural network(ANN) was proposed to model the non-linear relationship between parameters of aging process with respect to hardness and conductivity properties of Cu-Cr-Zr alloy. The improved model was developed by the Levenberg-Marquardt training algorithm. A basic repository on the domain knowledge of aging process was established via sufficient data mining by the network. The results show that the ANN system is effective and successful for predicting and analyzing the properties of Cu-Cr-Zr alloy.展开更多
The relationships between the surface quality of a single crystal copper ingot and the process parameters of heated mould continuous casting method were studied experimentally using our own design of horizontal heated...The relationships between the surface quality of a single crystal copper ingot and the process parameters of heated mould continuous casting method were studied experimentally using our own design of horizontal heated mould continuous casting apparatus, and the mechanism by which process parameters affect the surface quality of a single crystal copper ingot is analyzed in the present paper. The results show that the process parameters affect the surface quality of a pure copper ingot by affecting the position of the liquid-solid interface in the mould. The position of the liquid-solid interface in the mould must be controlled carefully within an appropriate range, which is determined through a series of experiments, in order to gain a single crystal copper ingot with good surface quality.展开更多
The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid p...The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid pickling, all kinds of copper oxides are removedcompletely, furthermore, no poisonous gases are given out and a smooth and clean surface of copperalloys is obtained. At present, the process is applied successfully in the copper-processingindustry.展开更多
Superhydrophilic surfaces were fabricated on copper substrates by an electrochemical deposition and sintering process. Superhydrophobic surfaces were prepared by constructing micro/nano-structure on copper substrates ...Superhydrophilic surfaces were fabricated on copper substrates by an electrochemical deposition and sintering process. Superhydrophobic surfaces were prepared by constructing micro/nano-structure on copper substrates through an electrochemical deposition method. Conversion from superhydrophobic to superhydrophilic was obtained via a suitable sintering process. After reduction sintering, the contact angle of the superhydrophilic surfaces changed from 155° to 0°. The scanning electron microscope (SEM) images show that the morphology of superhydrophobic and superhydrophilic surfaces looks like corals and cells respectively. The chemical composition and crystal structure of these surfaces were examined using energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results show that the main components on superhydrophobic surfaces are Cu, Cu2O and CuO, while the superhydrophilic surfaces are composed of Cu merely. The crystal structure is more inerratic and the grain size becomes bigger after the sintering. The interracial strength of the superhydrophilic surfaces was investigated, showing that the interfacial strength between superhydrophilic layer and copper substrate is considerably high.展开更多
The process parameters for bath autogenous smelting of copper were selected based on dynamic analysis of the experimental data and calculation of the mathematical model. Selecting the slag composition of SiO<sub>...The process parameters for bath autogenous smelting of copper were selected based on dynamic analysis of the experimental data and calculation of the mathematical model. Selecting the slag composition of SiO<sub>2</sub>/Fe=0.80 and CaO%=16. desulphur ratio less than 80 wt.-% in system. and the copper content of matte less than 60 wt.-%, it is able to limit Fe<sub>3</sub>O<sub>4</sub> formation and obtain a high desulphurization. The critical oxygen content of the blast increased with decrease of the sulphur content of the concentrate and increase of copper contents of the matte. If the copper contents of the concentrate are respectively of 30 and 35 wt.-%, the critical oxygen contents of the blast will be 48 and 69 wt.-% respectively. The smelling rate increases linearly with the blast intensity. When the sulphur content of the concentrate is 30 wt.-%, the oxygen content of the blast 70 vol.-% and the copper content of the matte 60 wt.-%, a blast intensityy of 700 Nm<sup>3</sup>/m<sup>2</sup>·h results in a smeling rate of 48.81 t/m<sup>2</sup>·d.展开更多
An approach to fabricate sintered copper with high green strength and high sintered density using nonaqueous gelcasting technol- ogy is presented in this study. The effects of various gelcasting processing parameters ...An approach to fabricate sintered copper with high green strength and high sintered density using nonaqueous gelcasting technol- ogy is presented in this study. The effects of various gelcasting processing parameters such as monomer content, monomer/crosslinker ratio, initiator content, dispersant dosage, and temperature on the flexural strength of dried green bodies and the relative density of sintered bodies were studied to obtain better microstructures and properties. The appropriate process parameters obtained for copper gelcasting are as follows monomer content, 20vol%-30vol% (based on the total volume of reagents); monomer/crosslinker ratio, 10:1 to 20:1; initiator content, 3vol%-4vol% (based on the volume of the monomer); dispersant dosage, 1.5wt%-2.5wt% (based on the mass of the copper powder); and reaction temperature, 65-75℃.展开更多
Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. ...Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. Herein, the recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation was conducted; process optimization was carried out, and the corresponding mineralogy was investigated. The reduction time, reduction temperature, reducing agent (coal), calcium chloride additive, grinding time, and magnetic field intensity were examined for process optimization. Mineralogical analyses of the sample, reduced pellets, and magnetic concentrate under various conditions were performed by X-ray diffraction, optical microscopy, and scanning electron microscopy-energy-dispersive X-ray spectrometry to elucidate the iron reduction and growth mechanisms. The results indicated that the optimum parameters of iron recovery include a reduction temperature of 1150A degrees C, a reduction time of 120 min, a coal dosage of 25%, a calcium chloride dosage of 2.5%, a magnetic field intensity of 100 mT, and a grinding time of 1 min. Under these conditions, the iron grade in the magnetic concentrate was greater than 90%, with an iron recovery ratio greater than 95%.展开更多
This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plan...This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plants in order to facilitate the extraction and subsequent concentration of the precious metal. Owing to cyanide solution employed in gold processing, effluents generated have high contents of free cyanide as well as copper cyanide complexes, which lend them a high degree of toxicity. In this regard, two options for the treatment of cyanide barren solutions has been used;in two ways;first for cyanide destruction by oxidation with the use of the EC process, in theory, has the advantage of decomposing cyanide at the anode and collecting copper simultaneously by a sludge of copper magnetic iron. In both cases excellent performance can be achieved using the high capacity of the bipolar iron EC technology. We found that it is possible to reduce the copper cyanide complex from 720 mg·l-1 to below 10 mg·l-1 within 20 minutes.展开更多
In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research resu...In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research results concerning the relationship between the Cu content of the matte and slag in the SKS process; the results are based on actual industrial production in the Dongying Fangyuan copper smelter. The results show that the matte grade strongly influences Cu losses in slag. The dissolved and entrained losses account for 10%–20% and 80%–90% of the total SKS industrial Cu losses in slag, respectively. With increasing matte grade, the dissolved and entrained Cu losses in the SKS slag both increase continuously. When the matte grade is greater than 68%, the content of Cu in the smelting slag increases much more dramatically. To obtain a high direct recovery of copper, the matte grade should be less than 75% in industrial SKS copper production.展开更多
Mathematical model for mass transfer of chemical reactions on the surface of the smelting bath pit in oxygen top blown smelting furnace was put forward. Additionally, one of two mathematical models for mass transfer o...Mathematical model for mass transfer of chemical reactions on the surface of the smelting bath pit in oxygen top blown smelting furnace was put forward. Additionally, one of two mathematical models for mass transfer of chemical reactions forming copper matte in smelting bath and the other for parameters of smelting process were developed. The verification tests were simultaneously carried out in a pilot scale furnace and the experimental results show that these mathematical models are convincing. Thus, these numerical models are reliable to simulate pyritic smelting process for copper nickel mineral in oxygen top blown furnace.展开更多
The effects of applied normal stress, surface roughness, and initial grain size on the microstructure of pure Cu developed during platen friction sliding deformation (PFSD) processing were investigated. In each case...The effects of applied normal stress, surface roughness, and initial grain size on the microstructure of pure Cu developed during platen friction sliding deformation (PFSD) processing were investigated. In each case, the deformation microstructure was characterized and the hardness of the treated surface layer was measured to evaluate its strength. The results indicated that the thickness of the deformed layer and the hardness at any depth increased with increasing normal stress. A smaller steel platen surface roughness resulted in less microstruc- tural refinement, whereas the microstructural refinement was enhanced by decreasing the surface roughness of the Cu sample. In the case of a very large initial grain size (d 〉 10 mm), a sharper transition from fine-grain microstructure to undeformed material was obtained in the treated surface layer after PFSD processing.展开更多
文摘In comparison with copper processing industrial leader Furukawa Electric Co., Ltd., Chinese copper processing industry faces many shortcomings and difficulties including but not limited to outdated equipment and technologies, low degree of specialization, and unstable product quality. The review of Furukawa Electric’s development milestones reveals that Chinese copper processing industry has reached a stage in which it must rely on technological research and development (R & D) to promote sustainable productivity. Chinese copper processing firms have to invest in R & D to promote sustainable technological innovations and to improve the precisions of business practice in order to ensure the firms’ improvement.
文摘Microstructural development of ultra low C, N, Fe-Cr alloy and pure copper processed by equal-channel angular pressing (ECAP) have been examined focusing on the initial stage of the formation of ultrafine grain structure. Fe-Cr alloys were pressed at 423 K while pure copper at room temperature for 1 to 3 passes via the route Bc to compare at the equivalent homologous temperature. Microstructural evolutions were characterized by electron backscatter diffraction (EBSD) image and transmission electron microscopy (TEM). It was found that deformation structures were mostly deformation-induced subboundaries in both the materials after one pass, but the fraction of high-angle grain boundary became higher in the Fe-Cr alloys than in pure copper in subsequent passes by increasing misorientation of the boundaries. The more enhanced formation of high angle boundaries in Fe-Cr alloys was discussed in terms of the nature of crystal slip of FCC and BCC structures.
基金supported in part by the National Key Research and Development Program of China(2021YFC2902703)the National Natural Science Foundation of China(62173078,61773105,61533007,61873049,61873053,61703085,61374147)。
文摘Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation industrial processes.This paper addresses the fluctuation problem of CCG through an operational optimization method.Firstly,a density-based affinity propagationalgorithm is proposed so that more ideal working condition categories can be obtained for the complex raw ore properties.Next,a Bayesian network(BN)is applied to explore the relationship between the operational variables and the CCG.Based on the analysis results of BN,a weighted Gaussian process regression model is constructed to predict the CCG that a higher prediction accuracy can be obtained.To ensure the predicted CCG is close to the set value with a smaller magnitude of the operation adjustments and a smaller uncertainty of the prediction results,an index-oriented adaptive differential evolution(IOADE)algorithm is proposed,and the convergence performance of IOADE is superior to the traditional differential evolution and adaptive differential evolution methods.Finally,the effectiveness and feasibility of the proposed methods are verified by the experiments on a copper flotation industrial process.
文摘China is the world’s largest producer of copper processing products as well as the world’s largest copper consumer market.In 2013,China produced more than 13.60 million tons of copper processing products,accounting for60%of the world’s total production.Since then,this proportion has expanded year by year,and will increase to about 66.7%in 2016.Meanwhile,China consumed nearly 11
文摘Tongling Nonferrous Metals Group Holdings Co.,Ltd.(referred to as Tongling Nonferrous)was profitable as for its copper processing sector in 2015.In 2017,its achievements continued by making historic breakthroughs:Tongguan Copper Foil Company realized a YOY growth of 208.63%;Tongguan Copper Product Branch has been making
文摘On May 15,the Southwestern Copper Production Base invested by Zhejiang Hailiang Co.,Ltd.,the world’s largest copper processing company,started construction in Luohuang Industrial Park,Jiangjin District.With a total investment of 3 billion yuan,the annual output value at maximum production capacity
基金Project (2004CB619200) supported by the National Basic Research Program of China
文摘The effects of the concentration of Lix 984N,phase ratio,initial pH value of aqueous phase and extraction time on the extraction of copper and iron under the condition of low Cu2+ /Fe3+ ratio in dump bioleaching solution of Dexing Copper Mine were explored.The optimal conditions of extraction are as follows: the concentration of Lix 984N 10%; the phase ratio (O/A) 1:1; the initial pH value of aqueous phase 1.5 and the mixing time 2 min.The stripping experiments show that H2SO4 solution could efficiently recover copper from the organic phase under the optimal conditions.
文摘Systematic physical simulation of thermo-mechanical processing routes has been ap-plied on a Gleeble 1500 simulator to four copper alloys (mass %) Cu-0.57Co-0.32Si,Cu-0.55Cr-0.065P, Cu-0.22Zr-0.035Si and Cu-1.01Ni-0.43Si aimed at clarifying theinfluences of processing conditions on their final properties, strength and electricalconductivity. Flow curves were determined over wide temperature and strain rateranges. Hardness was used as a measure of the strength level achieved. High hard-ness was obtained as using equal amounts (strains 0.5) of cold deformation beforeand after the precipitation annealing stage. The maximum values achieved for theCu-Co-Si, Cu-Cr-P, Cu-Zr-Si and Cu-Ni-Si alloys were 190, 165, 178 and 193 HV5,respectively. A thermo-mechanical schedule involving the hot deformation-ageing-colddeformation stages showed even better results for the Cu-Zr-Si alloy. Consequently,the processing routes were designed based on simulation test results and wires of 5 and2mm in diameters have been successfully processed in the industrial scale.
基金Project(60634020) supported by the National Natural Science Foundation of ChinaProject(2002CB312200) supported by the National Basic Research and Development Program of China
文摘Due to the importance of detecting the matte grade in the copper flash smelting process, the mechanism model was established according to the multi-phase and multi-component mathematic model. Meanwhile this procedure was a complicated production process with characteristics of large time delay, nonlinearity and so on. A fuzzy neural network model was set up through a great deal of production data. Besides a novel constrained gradient descent algorithm used to update the parameters was put forward to improve the parameters learning efficiency. Ultimately the self-adaptive combination technology was adopted to paralleled integrate two models in order to obtain the prediction model of the matte grade. Industrial data validation shows that the intelligently integrated model is more precise than a single model. It can not only predict the matte grade exactly but also provide optimal control of the copper flash smelting process with potent guidance.
文摘The aging hardening process makes it possible to get higher hardness and electrical conductivity of lead frame copper alloy. The process has only been studied empirically by trial-and-error method so far. The use of a supervised artificial neural network(ANN) was proposed to model the non-linear relationship between parameters of aging process with respect to hardness and conductivity properties of Cu-Cr-Zr alloy. The improved model was developed by the Levenberg-Marquardt training algorithm. A basic repository on the domain knowledge of aging process was established via sufficient data mining by the network. The results show that the ANN system is effective and successful for predicting and analyzing the properties of Cu-Cr-Zr alloy.
文摘The relationships between the surface quality of a single crystal copper ingot and the process parameters of heated mould continuous casting method were studied experimentally using our own design of horizontal heated mould continuous casting apparatus, and the mechanism by which process parameters affect the surface quality of a single crystal copper ingot is analyzed in the present paper. The results show that the process parameters affect the surface quality of a pure copper ingot by affecting the position of the liquid-solid interface in the mould. The position of the liquid-solid interface in the mould must be controlled carefully within an appropriate range, which is determined through a series of experiments, in order to gain a single crystal copper ingot with good surface quality.
文摘The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid pickling, all kinds of copper oxides are removedcompletely, furthermore, no poisonous gases are given out and a smooth and clean surface of copperalloys is obtained. At present, the process is applied successfully in the copper-processingindustry.
基金Supported by the National Natural Science Foundation of China(51275180)the Fundamental Research Funds for the Central Universities(2013ZM0003)the Doctorate Dissertation Funds of Guangdong Province(sybzzxm 201213)
文摘Superhydrophilic surfaces were fabricated on copper substrates by an electrochemical deposition and sintering process. Superhydrophobic surfaces were prepared by constructing micro/nano-structure on copper substrates through an electrochemical deposition method. Conversion from superhydrophobic to superhydrophilic was obtained via a suitable sintering process. After reduction sintering, the contact angle of the superhydrophilic surfaces changed from 155° to 0°. The scanning electron microscope (SEM) images show that the morphology of superhydrophobic and superhydrophilic surfaces looks like corals and cells respectively. The chemical composition and crystal structure of these surfaces were examined using energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results show that the main components on superhydrophobic surfaces are Cu, Cu2O and CuO, while the superhydrophilic surfaces are composed of Cu merely. The crystal structure is more inerratic and the grain size becomes bigger after the sintering. The interracial strength of the superhydrophilic surfaces was investigated, showing that the interfacial strength between superhydrophilic layer and copper substrate is considerably high.
文摘The process parameters for bath autogenous smelting of copper were selected based on dynamic analysis of the experimental data and calculation of the mathematical model. Selecting the slag composition of SiO<sub>2</sub>/Fe=0.80 and CaO%=16. desulphur ratio less than 80 wt.-% in system. and the copper content of matte less than 60 wt.-%, it is able to limit Fe<sub>3</sub>O<sub>4</sub> formation and obtain a high desulphurization. The critical oxygen content of the blast increased with decrease of the sulphur content of the concentrate and increase of copper contents of the matte. If the copper contents of the concentrate are respectively of 30 and 35 wt.-%, the critical oxygen contents of the blast will be 48 and 69 wt.-% respectively. The smelling rate increases linearly with the blast intensity. When the sulphur content of the concentrate is 30 wt.-%, the oxygen content of the blast 70 vol.-% and the copper content of the matte 60 wt.-%, a blast intensityy of 700 Nm<sup>3</sup>/m<sup>2</sup>·h results in a smeling rate of 48.81 t/m<sup>2</sup>·d.
基金financially supported by the National Science Foundation of China (Grant No. 51274041)
文摘An approach to fabricate sintered copper with high green strength and high sintered density using nonaqueous gelcasting technol- ogy is presented in this study. The effects of various gelcasting processing parameters such as monomer content, monomer/crosslinker ratio, initiator content, dispersant dosage, and temperature on the flexural strength of dried green bodies and the relative density of sintered bodies were studied to obtain better microstructures and properties. The appropriate process parameters obtained for copper gelcasting are as follows monomer content, 20vol%-30vol% (based on the total volume of reagents); monomer/crosslinker ratio, 10:1 to 20:1; initiator content, 3vol%-4vol% (based on the volume of the monomer); dispersant dosage, 1.5wt%-2.5wt% (based on the mass of the copper powder); and reaction temperature, 65-75℃.
基金financially supported by the National Natural Science Foundation of China (No. 51674026)
文摘Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. Herein, the recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation was conducted; process optimization was carried out, and the corresponding mineralogy was investigated. The reduction time, reduction temperature, reducing agent (coal), calcium chloride additive, grinding time, and magnetic field intensity were examined for process optimization. Mineralogical analyses of the sample, reduced pellets, and magnetic concentrate under various conditions were performed by X-ray diffraction, optical microscopy, and scanning electron microscopy-energy-dispersive X-ray spectrometry to elucidate the iron reduction and growth mechanisms. The results indicated that the optimum parameters of iron recovery include a reduction temperature of 1150A degrees C, a reduction time of 120 min, a coal dosage of 25%, a calcium chloride dosage of 2.5%, a magnetic field intensity of 100 mT, and a grinding time of 1 min. Under these conditions, the iron grade in the magnetic concentrate was greater than 90%, with an iron recovery ratio greater than 95%.
文摘This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plants in order to facilitate the extraction and subsequent concentration of the precious metal. Owing to cyanide solution employed in gold processing, effluents generated have high contents of free cyanide as well as copper cyanide complexes, which lend them a high degree of toxicity. In this regard, two options for the treatment of cyanide barren solutions has been used;in two ways;first for cyanide destruction by oxidation with the use of the EC process, in theory, has the advantage of decomposing cyanide at the anode and collecting copper simultaneously by a sludge of copper magnetic iron. In both cases excellent performance can be achieved using the high capacity of the bipolar iron EC technology. We found that it is possible to reduce the copper cyanide complex from 720 mg·l-1 to below 10 mg·l-1 within 20 minutes.
基金financially supported by the National Natural Science Foundation of China (No. 51620105013)Dongying Fangyuan Nonferrous Metals Co., Ltd.
文摘In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research results concerning the relationship between the Cu content of the matte and slag in the SKS process; the results are based on actual industrial production in the Dongying Fangyuan copper smelter. The results show that the matte grade strongly influences Cu losses in slag. The dissolved and entrained losses account for 10%–20% and 80%–90% of the total SKS industrial Cu losses in slag, respectively. With increasing matte grade, the dissolved and entrained Cu losses in the SKS slag both increase continuously. When the matte grade is greater than 68%, the content of Cu in the smelting slag increases much more dramatically. To obtain a high direct recovery of copper, the matte grade should be less than 75% in industrial SKS copper production.
文摘Mathematical model for mass transfer of chemical reactions on the surface of the smelting bath pit in oxygen top blown smelting furnace was put forward. Additionally, one of two mathematical models for mass transfer of chemical reactions forming copper matte in smelting bath and the other for parameters of smelting process were developed. The verification tests were simultaneously carried out in a pilot scale furnace and the experimental results show that these mathematical models are convincing. Thus, these numerical models are reliable to simulate pyritic smelting process for copper nickel mineral in oxygen top blown furnace.
基金the Danish National Research Foundation (Grant No. DNRF86-5)the National Natural Science Foundation of China (Grant Nos. 51261130091 and 51171085) to the Danish–Chinese Center for Nanometals
文摘The effects of applied normal stress, surface roughness, and initial grain size on the microstructure of pure Cu developed during platen friction sliding deformation (PFSD) processing were investigated. In each case, the deformation microstructure was characterized and the hardness of the treated surface layer was measured to evaluate its strength. The results indicated that the thickness of the deformed layer and the hardness at any depth increased with increasing normal stress. A smaller steel platen surface roughness resulted in less microstruc- tural refinement, whereas the microstructural refinement was enhanced by decreasing the surface roughness of the Cu sample. In the case of a very large initial grain size (d 〉 10 mm), a sharper transition from fine-grain microstructure to undeformed material was obtained in the treated surface layer after PFSD processing.