Using VAR-DCC-GARCH model,the literature on commodity price was extended by exploring the co-movement between Chinese nonferrous metal prices and global nonferrous metal prices represented by the nonferrous metal pric...Using VAR-DCC-GARCH model,the literature on commodity price was extended by exploring the co-movement between Chinese nonferrous metal prices and global nonferrous metal prices represented by the nonferrous metal prices from London Metal Exchange(LME).The results show that LME nonferrous metals prices still have a greater impact on Chinese nonferrous metals prices.However,the impact of Chinese nonferrous metals prices on LME nonferrous metals prices is still weak except for lead price.The co-movement of nonferrous metal prices between LME and China presents hysteretic nature,and it lasts for 7-8trading days.Furthermore,the co-movement between LME nonferrous metals prices and Chinese nonferrous metals prices has the characteristics of time-varying,and the correlation of lead prices between LME and China is the more stable than all other nonferrous metals prices.展开更多
Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and ...Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and its change during the period of 2007 and 2011. Based on financial data from nonferrous metals listed companies, technical efficiency of nonferrous metal minerals mining firms and nonferrous metal smelting, pressing and processing firms was estimated respectively using the data envelopment analysis (DEA) method. It was found that, in both sectors, number of pure technical and scale inefficient firms dominated over efficient ones. Overall, their technical and scale efficiency tended to be very low after 2009. In particular, efficiency scores of nonferrous metal smelting, pressing and processing firms fluctuated greatly during the research period. And a limited number of large leading firms were able to maintain 100% efficiency score in the industry, while efficiency of most of other leading firms has declined since 2009.展开更多
The aim of the present work is to examine whether the price volatility of nonferrous metal futures can be used to predict the aggregate stock market returns in China. During a sample period from January of 2004 to Dec...The aim of the present work is to examine whether the price volatility of nonferrous metal futures can be used to predict the aggregate stock market returns in China. During a sample period from January of 2004 to December of 2011, empirical results show that the price volatility of basic nonferrous metals is a good predictor of value-weighted stock portfolio at various horizons in both in-sample and out-of-sample regressions. The predictive power of metal copper volatility is greater than that of aluminum. The results are robust to alternative measurements of variables and econometric approaches. After controlling several well-known macro pricing variables, the predictive power of copper volatility declines but remains statistically significant. Since the predictability exists only during our sample period, we conjecture that the stock market predictability by metal price volatility is partly driven by commodity financialization.展开更多
The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals (copper, aluminum and zinc) pricesincorporating structural changes. The ...The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals (copper, aluminum and zinc) pricesincorporating structural changes. The results show that copper, aluminum and zinc returns have many structure breaks points, and nonferrous metals have the greatvolatilityrisk during financial crisis. From the resultsof GARCH with and without structural changes,it isfoundthat the volatility clustering of single nonferrous metal is overvalued when ignoring the structural mutation, and the return of aluminum isthe most overvalued, indicating that aluminum market is more susceptible to external shock.Furthermore,it is also foundthatdynamic volatility correlation exists in the three prices of nonferrous metals, and the structural changes have no significant effect on the volatility correlation of thethree nonferrous metals.展开更多
As China's most important gold-producing district, the Jiaodong Peninsula also contains copper, lead-zinc, molybdenum (tungsten), and other nonferrous metal ore deposits, but the space-time and genetic relationship...As China's most important gold-producing district, the Jiaodong Peninsula also contains copper, lead-zinc, molybdenum (tungsten), and other nonferrous metal ore deposits, but the space-time and genetic relationships with gold deposits remain uncertain. To investigate the temporal relationship between these nonferrous metal and gold ore deposits, We collected the samples from a number of nonferrous metallic and silver deposits and metallogenetic rock bodies in the eastern Jiaodong Peninsula for isotopic dating. The results show that the Re-Os isotopic model ages of the Lengjia molybdenum deposit in Rongcheng range from 114.5 ± 1.8 Ma to 112.6 ± 1.5 Ma, with an average age of 113.6 ± 1.6 Ma; the LA-ICP-MS ^206pb/^238U ages of 33 zircons in the sericitization porphyritic monzogranite that hosts the Tongjiazhuang silver deposit in Rongcheng range between 122 Ma and 109 Ma, with a weighted mean age of 116.04 ± 0.95 Ma; the LA-ICP-MS ^206pb/^238U ages of 31 zircons in the copper metallogenic pyroxene monzodiorite that hosts the Kuangbei copper deposit in Rongcheng range from 126 Ma to 106 Ma, with a weighted mean age of 116.6 ± 1.7 Ma; and the LA-ICP-MS ^206pb/^238U ages of 19 zircons in the pyroxene monzodiorite surrounding the Dadengge gold and multimetal deposit in Weihai range from 113 Ma to 110 Ma, with a weighted mean age of 111.7 ± 0.6 Ma. All these results indicate that the metallogenic ages of the silver and nonferrous metallic deposits in the Jiaodong Peninsula are in a limited range from 118 Ma to 111 Ma. Previous studies have demonstrated that the isotopic ages of gold deposits in the Jiaodong Peninsula range from 123 Ma to 110 Ma, while Weideshanian magmatism occurred between 126 Ma to 108 Ma. Both these ranges are grossly consistent with the metallogenic ages of silver and nonferrous metallic deposits in this study, suggesting that the large-scale mineralization occurred in the Early Cretaceous when magmatic activities were strong. This epoch may be linked to the lithosphere thinning and the thermo-upwelling extension in eastern China at that time. In addition, field investigation also shows that gold and nonferrous metallic deposits are distributed nearby the Weideshanian granite, with the nonferrous metallic deposits lying within or surrounding the granite pluton and the gold deposits outside the granite pluton. We propose the following mineralization scenario: In the Early Cretaceous, an intensive lithospheric extension induced partial melting and degassing of the metasomatized lithospheric mantle, which resulted in the formation of mantle-derived fluids enriched in metal elements. During the rapid process of magma ascent and intrusion, crust-derived fluids were activated by the magmatic thermal dome and served to further extract ore-forming materials from the crust. These fluids may have mixed with the mantle-derived fluid to form a crust-mantle mixing-type ore-forming fluid. The high-temperature conditions in the center or in contact with the granitic magmatic thermal dome would have been favorable for the formation of porphyry-type, skarn-type, and hydrothermal-vein-type ores, thus forming a series of Mo(W), Cu, and Pb-Zn deposits in the mid-eastern Jiaodong Peninsula. In contrast, the medium- to low-temperature conditions in the periphery of the magmatic thermal dome would have favored the deposition of gold (silver) ores under the appropriate physiochemical and structural conditions. The metaliogenic epoch of the molybdenum, copper, and silver deposits, and their spatio-temporal and genetic relations to the gold deposits, as demonstrated in this study, not only provide important insights to the study of regional metallogeny, our understanding of the metallogenesis of the Jiaodong type gold deposit, and the geodynamic background of the large-scale mineralization in the Jiaodong Peninsula, but also have practical value in guiding the mineral exploration.展开更多
Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extractio...Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.展开更多
The nonferrous metallurgical(NFM)industry is a cornerstone industry for a nation’s economy.With the development of artificial technologies and high requirements on environment protection,product quality,and productio...The nonferrous metallurgical(NFM)industry is a cornerstone industry for a nation’s economy.With the development of artificial technologies and high requirements on environment protection,product quality,and production efficiency,the importance of applying smart manufacturing technologies to comprehensively percept production states and intelligently optimize process operations is becoming widely recognized by the industry.As a brief summary of the smart and optimal manufacturing of the NFM industry,this paper first reviews the research progress on some key facets of the operational optimization of NFM processes,including production and management,blending optimization,modeling,process monitoring,optimization,and control.Then,it illustrates the perspectives of smart and optimal manufacturing of the NFM industry.Finally,it discusses the major research directions and challenges of smart and optimal manufacturing for the NFM industry.This paper will lay a foundation for the realization of smart and optimal manufacturing in nonferrous metallurgy in the future.展开更多
Environmental exposure to heavy metals has been linked to a wide range of human health hazards. We detected the levels of 15 metals in urine samples from 500 representative sub-samples in an ongoing occupational cohor...Environmental exposure to heavy metals has been linked to a wide range of human health hazards. We detected the levels of 15 metals in urine samples from 500 representative sub-samples in an ongoing occupational cohort study (Jinchang Cohort) to directly evaluate metal exposure levels. Fifteen metals, namely As, Ba, Be, Cd, Cs, Cr, Co, Cu, Pb, Mn, Ni, Se, TI, U, and Zn, were detected by inductively coupled plasma quadruple mass spectrometry. The results showed that median creatinine adjustment and geometric mean urinary metal levels were higher in the heavy metal-exposed group, except Se and Zn, than other reported general or occupational populations. Further studies should address the effects of heavy metals on human health.展开更多
Co-grinding three nonferrous metal oxides(CuO,PbO and ZnO)with element sulphur under mild conditions and flotation of the ground samples were conducted to investigate the surface properties and floatability of the oxi...Co-grinding three nonferrous metal oxides(CuO,PbO and ZnO)with element sulphur under mild conditions and flotation of the ground samples were conducted to investigate the surface properties and floatability of the oxides.Phase transition,morphological features,electrochemical properties and surface chemical compositions of ground samples were studied.The results show that the floatability of CuO is improved after grinding with sulfur,by the formation of surface layer with properties similar to CuS due to the Cu-S bonding.The floatability of PbO is deteriorated after mechanochemical processing due to surface carbonation and the formation of PbS and PbSO4by disproportionation reaction with sulfur.ZnO shows no evident response to mechanochemical sulfidation.展开更多
This paper seeks to model and forecast the Chinese nonferrous metals futures market volatility and allows new insights into the time-varying volatility of realized volatility and leverage effects using high-frequency ...This paper seeks to model and forecast the Chinese nonferrous metals futures market volatility and allows new insights into the time-varying volatility of realized volatility and leverage effects using high-frequency data.The LHAR-CJ model is extended and the empirical research on copper and aluminum futures in Shanghai Futures Exchange suggests the dynamic dependencies and time-varying volatility of realized volatility,which are captured by long memory HAR-GARCH model.Besides,the findings also show the significant weekly leverage effects in Chinese nonferrous metals futures market volatility.Finally,in-sample and out-of-sample forecasts are investigated,and the results show that the LHAR-CJ-G model,considering time-varyingvolatility of realized volatility and leverage effects,effectively improves the explanatory power as well as out-of sample predictive performance.展开更多
The correlation between Renminbi(RMB) internationalization and nonferrous metal prices was studied using the nonlinear Granger causality test and the dynamic conditional correlation-generalized autoregressive conditio...The correlation between Renminbi(RMB) internationalization and nonferrous metal prices was studied using the nonlinear Granger causality test and the dynamic conditional correlation-generalized autoregressive conditional heteroskedastic(DCC-GARCH) model. The results indicate that the relationship between RMB internationalization and nonferrous metal prices reflects a complex nonlinear mechanism. There was no mutual influence between RMB internationalization and nonferrous metal prices prior to the trials of the RMB settlement in the cross-border trade in July 2009. Since then, however, a bidirectional causal relationship between RMB internationalization and the price of copper and a unidirectional causal relationship from the price of aluminum to RMB internationalization were examined. In addition, due to the impact of extreme events, such as economic and financial crises, RMB internationalization and nonferrous metal prices are not always positively correlated but are rather occasionally negatively correlated.展开更多
The 13th China International Diecasting Congress & Exhibition(CHINA DIECASTING 2018) and 2018 China NonferrousAlloys & Special Casting Exhibition (CHINA NONFERROUS2018) were held concurrently July 18-20 at Shang...The 13th China International Diecasting Congress & Exhibition(CHINA DIECASTING 2018) and 2018 China NonferrousAlloys & Special Casting Exhibition (CHINA NONFERROUS2018) were held concurrently July 18-20 at Shanghai NewInternational Expo Centre. The events were co-organized bythe Foundry Institution of Chinese Mechanical EngineeringSociety (FICMES), Shenyang Zhongzhu Foundry ProductivityPromotion Center Co., Ltd. (FPC) and the State Key Laboratoryof Light Alloys Casting Technologies for High-end Equipment.展开更多
The new magnetic-assisted abrasive polishing process for non-ferrous materials was proposed in order to increase the magnetic flux density which directly influences the contact force between the workpiece and the abra...The new magnetic-assisted abrasive polishing process for non-ferrous materials was proposed in order to increase the magnetic flux density which directly influences the contact force between the workpiece and the abrasives.The permanent magnets were installed under the workpiece and their effects were verified by the experiments.The effect of polishing factors on the improvement of surface roughness was evaluated based on the Taguchi experimental method,and the optimal conditions for polishing AISI316 stainless steel were determined.The predicting model for improving surface roughness was developed and the validity of the developed model was tested.The results show that the permanent magnets are very useful in improving the surface roughness in the magnetic-assisted abrasive polishing process.展开更多
Our research and investigation proves thatthe growth rate of the productivity of thenonferrous metals industry is much lower thanthat of investment,and that the potential for in-creasing productivity iS very grear,in ...Our research and investigation proves thatthe growth rate of the productivity of thenonferrous metals industry is much lower thanthat of investment,and that the potential for in-creasing productivity iS very grear,in spite of thecompplicated influence of multiple weak joints re-strieting the increase of the productivity.To solvethese problems,following policies should展开更多
The definition of a plain bearing is given.The requirements for bearing materials are pro-posed.The historical perspective and recent development of the bearing materials are intro-duced,and the performances of curren...The definition of a plain bearing is given.The requirements for bearing materials are pro-posed.The historical perspective and recent development of the bearing materials are intro-duced,and the performances of current bearing materials are展开更多
The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of im...The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of improving the productivity of the nonferrous metals industry have been discussed.展开更多
Founded in January of 1984,China National Nonferrous Metals Import and Export Corporation(CNIEC)is a combined industrial and trading subsidiary of China National Nonferrous Metals Industry Corporation(CNNC).Establishe...Founded in January of 1984,China National Nonferrous Metals Import and Export Corporation(CNIEC)is a combined industrial and trading subsidiary of China National Nonferrous Metals Industry Corporation(CNNC).Established in part as a result of China's economic reforms and open door policies,it aims to better utilize the resources and finances of both the domestic and overseas markets to develop China's nonferrous metals industry.Two of CNIEC's most important objectives are to regulate state economic and trade activities within the nonferrous metals industry and to actively compete in the international market through the importation and exportation of nonferrous metals commodities equipment and technology.展开更多
The outbreak of COVID-19 early this year has accelerated the industry reshuffle.It is a critical period for companies to think about a long-term development strategy,optimize supply chains,and promote innovation-drive...The outbreak of COVID-19 early this year has accelerated the industry reshuffle.It is a critical period for companies to think about a long-term development strategy,optimize supply chains,and promote innovation-driven development.In the theme of "Digitalization Application and Intelligent Development in High-Efficient Die Casting Manufacturing",the event this year gathered 262 exhibitors from 9 countries and regions,among which international exhibitors account for 21%,and 11,986 trade visitors working in nonferrous,die casting and related application fields.展开更多
China Nonferrous Metals Scientific and Technical Joint-Development Group(CNJDG)consists of thirty odd research,design institutions,universities,colleges,plants,mines,enterprisesand consulting companies(see attached li...China Nonferrous Metals Scientific and Technical Joint-Development Group(CNJDG)consists of thirty odd research,design institutions,universities,colleges,plants,mines,enterprisesand consulting companies(see attached list of membership units)CNJDG has a business executive organization—Nonferrous Metals Scientific and TechnicalDevelopment Corporation(NSTDC)to suit client’s convenience.展开更多
This paper introduces the refractories used in various nonferrous metal smelting equipment in China and the existing problems, and puts forward suggestions on the material of refractories, application of new technolog...This paper introduces the refractories used in various nonferrous metal smelting equipment in China and the existing problems, and puts forward suggestions on the material of refractories, application of new technologies and production management of refractories, etc.展开更多
基金Project(71073177)supported by the National Natural Science Foundation of ChinaProject(12JJ4077)supported by the Natural Science Foundation of Hunan Province of ChinaProject(2012zzts002)supported by the Fundamental Research Funds of Central South University,China
文摘Using VAR-DCC-GARCH model,the literature on commodity price was extended by exploring the co-movement between Chinese nonferrous metal prices and global nonferrous metal prices represented by the nonferrous metal prices from London Metal Exchange(LME).The results show that LME nonferrous metals prices still have a greater impact on Chinese nonferrous metals prices.However,the impact of Chinese nonferrous metals prices on LME nonferrous metals prices is still weak except for lead price.The co-movement of nonferrous metal prices between LME and China presents hysteretic nature,and it lasts for 7-8trading days.Furthermore,the co-movement between LME nonferrous metals prices and Chinese nonferrous metals prices has the characteristics of time-varying,and the correlation of lead prices between LME and China is the more stable than all other nonferrous metals prices.
基金Project(70921001)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0799)supported by Program for New Century Excellent Talents in University,ChinaProjects(11YJA790158)supported by Humanities and Social Sciences Planning Fund by Chinese Ministry of Education
文摘Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and its change during the period of 2007 and 2011. Based on financial data from nonferrous metals listed companies, technical efficiency of nonferrous metal minerals mining firms and nonferrous metal smelting, pressing and processing firms was estimated respectively using the data envelopment analysis (DEA) method. It was found that, in both sectors, number of pure technical and scale inefficient firms dominated over efficient ones. Overall, their technical and scale efficiency tended to be very low after 2009. In particular, efficiency scores of nonferrous metal smelting, pressing and processing firms fluctuated greatly during the research period. And a limited number of large leading firms were able to maintain 100% efficiency score in the industry, while efficiency of most of other leading firms has declined since 2009.
基金Project(71071166)supported by the National Natural Science Foundation of China
文摘The aim of the present work is to examine whether the price volatility of nonferrous metal futures can be used to predict the aggregate stock market returns in China. During a sample period from January of 2004 to December of 2011, empirical results show that the price volatility of basic nonferrous metals is a good predictor of value-weighted stock portfolio at various horizons in both in-sample and out-of-sample regressions. The predictive power of metal copper volatility is greater than that of aluminum. The results are robust to alternative measurements of variables and econometric approaches. After controlling several well-known macro pricing variables, the predictive power of copper volatility declines but remains statistically significant. Since the predictability exists only during our sample period, we conjecture that the stock market predictability by metal price volatility is partly driven by commodity financialization.
基金Project(71072079)supported by the National Natural Science Foundation of China
文摘The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals (copper, aluminum and zinc) pricesincorporating structural changes. The results show that copper, aluminum and zinc returns have many structure breaks points, and nonferrous metals have the greatvolatilityrisk during financial crisis. From the resultsof GARCH with and without structural changes,it isfoundthat the volatility clustering of single nonferrous metal is overvalued when ignoring the structural mutation, and the return of aluminum isthe most overvalued, indicating that aluminum market is more susceptible to external shock.Furthermore,it is also foundthatdynamic volatility correlation exists in the three prices of nonferrous metals, and the structural changes have no significant effect on the volatility correlation of thethree nonferrous metals.
基金funded by Taishan Scholar Special Project Funds(ts201511076)Key Research and Development Project of Shandong Province(2017CXGC1604)
文摘As China's most important gold-producing district, the Jiaodong Peninsula also contains copper, lead-zinc, molybdenum (tungsten), and other nonferrous metal ore deposits, but the space-time and genetic relationships with gold deposits remain uncertain. To investigate the temporal relationship between these nonferrous metal and gold ore deposits, We collected the samples from a number of nonferrous metallic and silver deposits and metallogenetic rock bodies in the eastern Jiaodong Peninsula for isotopic dating. The results show that the Re-Os isotopic model ages of the Lengjia molybdenum deposit in Rongcheng range from 114.5 ± 1.8 Ma to 112.6 ± 1.5 Ma, with an average age of 113.6 ± 1.6 Ma; the LA-ICP-MS ^206pb/^238U ages of 33 zircons in the sericitization porphyritic monzogranite that hosts the Tongjiazhuang silver deposit in Rongcheng range between 122 Ma and 109 Ma, with a weighted mean age of 116.04 ± 0.95 Ma; the LA-ICP-MS ^206pb/^238U ages of 31 zircons in the copper metallogenic pyroxene monzodiorite that hosts the Kuangbei copper deposit in Rongcheng range from 126 Ma to 106 Ma, with a weighted mean age of 116.6 ± 1.7 Ma; and the LA-ICP-MS ^206pb/^238U ages of 19 zircons in the pyroxene monzodiorite surrounding the Dadengge gold and multimetal deposit in Weihai range from 113 Ma to 110 Ma, with a weighted mean age of 111.7 ± 0.6 Ma. All these results indicate that the metallogenic ages of the silver and nonferrous metallic deposits in the Jiaodong Peninsula are in a limited range from 118 Ma to 111 Ma. Previous studies have demonstrated that the isotopic ages of gold deposits in the Jiaodong Peninsula range from 123 Ma to 110 Ma, while Weideshanian magmatism occurred between 126 Ma to 108 Ma. Both these ranges are grossly consistent with the metallogenic ages of silver and nonferrous metallic deposits in this study, suggesting that the large-scale mineralization occurred in the Early Cretaceous when magmatic activities were strong. This epoch may be linked to the lithosphere thinning and the thermo-upwelling extension in eastern China at that time. In addition, field investigation also shows that gold and nonferrous metallic deposits are distributed nearby the Weideshanian granite, with the nonferrous metallic deposits lying within or surrounding the granite pluton and the gold deposits outside the granite pluton. We propose the following mineralization scenario: In the Early Cretaceous, an intensive lithospheric extension induced partial melting and degassing of the metasomatized lithospheric mantle, which resulted in the formation of mantle-derived fluids enriched in metal elements. During the rapid process of magma ascent and intrusion, crust-derived fluids were activated by the magmatic thermal dome and served to further extract ore-forming materials from the crust. These fluids may have mixed with the mantle-derived fluid to form a crust-mantle mixing-type ore-forming fluid. The high-temperature conditions in the center or in contact with the granitic magmatic thermal dome would have been favorable for the formation of porphyry-type, skarn-type, and hydrothermal-vein-type ores, thus forming a series of Mo(W), Cu, and Pb-Zn deposits in the mid-eastern Jiaodong Peninsula. In contrast, the medium- to low-temperature conditions in the periphery of the magmatic thermal dome would have favored the deposition of gold (silver) ores under the appropriate physiochemical and structural conditions. The metaliogenic epoch of the molybdenum, copper, and silver deposits, and their spatio-temporal and genetic relations to the gold deposits, as demonstrated in this study, not only provide important insights to the study of regional metallogeny, our understanding of the metallogenesis of the Jiaodong type gold deposit, and the geodynamic background of the large-scale mineralization in the Jiaodong Peninsula, but also have practical value in guiding the mineral exploration.
基金Project(50904031) supported by the National Natural Science Foundation of ChinaProject(2008E0049M) supported by the Natural Science Foundation of Yunnan Province,China+1 种基金Project(07Z40082) supported by the Science Foundation of the Education Department of Yunnan Province,ChinaProject(2007-16) supported by the Science Foundation of Kunming University of Science and Technology,China
文摘Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.
基金financially supported by the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.61860206014)the Basic Science Research Center Program of National Natural Science Foundation of China(No.61988101)+2 种基金National Key Research and Development Program(No.2020YFB1713700)National Natural Science Foundation of China(Nos.61973321 and 62073342)Science and Technology Innovation Program of Hunan Province(No.2021RC4054).
文摘The nonferrous metallurgical(NFM)industry is a cornerstone industry for a nation’s economy.With the development of artificial technologies and high requirements on environment protection,product quality,and production efficiency,the importance of applying smart manufacturing technologies to comprehensively percept production states and intelligently optimize process operations is becoming widely recognized by the industry.As a brief summary of the smart and optimal manufacturing of the NFM industry,this paper first reviews the research progress on some key facets of the operational optimization of NFM processes,including production and management,blending optimization,modeling,process monitoring,optimization,and control.Then,it illustrates the perspectives of smart and optimal manufacturing of the NFM industry.Finally,it discusses the major research directions and challenges of smart and optimal manufacturing for the NFM industry.This paper will lay a foundation for the realization of smart and optimal manufacturing in nonferrous metallurgy in the future.
基金supported by Project of Employees Health Status and Disease Burden Trend Study in Jinchua Nonferrous Metals Corporation,Grant JKB20120013Fogarty training grants D43TW 008323and D43TW 007864-01 from the US National Institutes of Health
文摘Environmental exposure to heavy metals has been linked to a wide range of human health hazards. We detected the levels of 15 metals in urine samples from 500 representative sub-samples in an ongoing occupational cohort study (Jinchang Cohort) to directly evaluate metal exposure levels. Fifteen metals, namely As, Ba, Be, Cd, Cs, Cr, Co, Cu, Pb, Mn, Ni, Se, TI, U, and Zn, were detected by inductively coupled plasma quadruple mass spectrometry. The results showed that median creatinine adjustment and geometric mean urinary metal levels were higher in the heavy metal-exposed group, except Se and Zn, than other reported general or occupational populations. Further studies should address the effects of heavy metals on human health.
文摘Co-grinding three nonferrous metal oxides(CuO,PbO and ZnO)with element sulphur under mild conditions and flotation of the ground samples were conducted to investigate the surface properties and floatability of the oxides.Phase transition,morphological features,electrochemical properties and surface chemical compositions of ground samples were studied.The results show that the floatability of CuO is improved after grinding with sulfur,by the formation of surface layer with properties similar to CuS due to the Cu-S bonding.The floatability of PbO is deteriorated after mechanochemical processing due to surface carbonation and the formation of PbS and PbSO4by disproportionation reaction with sulfur.ZnO shows no evident response to mechanochemical sulfidation.
基金Project(13&ZD169)supported by the Major Program of the National Social Science Foundation of ChinaProject(2016zzts009)supported by Doctoral Students Independent Explore Innovation Project of Central South University,China+3 种基金Project(13YJAZH149)supported by the Social Science Foundation of Ministry of Education of ChinaProject(2015JJ2182)supported by the Social Science Foundation of Hunan Province,ChinaProject(71573282)supported by the National Natural Science Foundation of ChinaProject(15K133)supported by the Educational Commission of Hunan Province of China
文摘This paper seeks to model and forecast the Chinese nonferrous metals futures market volatility and allows new insights into the time-varying volatility of realized volatility and leverage effects using high-frequency data.The LHAR-CJ model is extended and the empirical research on copper and aluminum futures in Shanghai Futures Exchange suggests the dynamic dependencies and time-varying volatility of realized volatility,which are captured by long memory HAR-GARCH model.Besides,the findings also show the significant weekly leverage effects in Chinese nonferrous metals futures market volatility.Finally,in-sample and out-of-sample forecasts are investigated,and the results show that the LHAR-CJ-G model,considering time-varyingvolatility of realized volatility and leverage effects,effectively improves the explanatory power as well as out-of sample predictive performance.
基金Projects(71874210,71633006,71874207,71974208)supported by the National Natural Science Foundation of ChinaProject(2020CX049)supported by Innovation-Driven Foundation of Central South University,China+1 种基金Project(2018dcyj031)supported by Postgraduate Survey Research Foundation of Central South University,ChinaProject(17K103)supported by the Innovation Platform Open Fund Project of Hunan Education Department,China。
文摘The correlation between Renminbi(RMB) internationalization and nonferrous metal prices was studied using the nonlinear Granger causality test and the dynamic conditional correlation-generalized autoregressive conditional heteroskedastic(DCC-GARCH) model. The results indicate that the relationship between RMB internationalization and nonferrous metal prices reflects a complex nonlinear mechanism. There was no mutual influence between RMB internationalization and nonferrous metal prices prior to the trials of the RMB settlement in the cross-border trade in July 2009. Since then, however, a bidirectional causal relationship between RMB internationalization and the price of copper and a unidirectional causal relationship from the price of aluminum to RMB internationalization were examined. In addition, due to the impact of extreme events, such as economic and financial crises, RMB internationalization and nonferrous metal prices are not always positively correlated but are rather occasionally negatively correlated.
文摘The 13th China International Diecasting Congress & Exhibition(CHINA DIECASTING 2018) and 2018 China NonferrousAlloys & Special Casting Exhibition (CHINA NONFERROUS2018) were held concurrently July 18-20 at Shanghai NewInternational Expo Centre. The events were co-organized bythe Foundry Institution of Chinese Mechanical EngineeringSociety (FICMES), Shenyang Zhongzhu Foundry ProductivityPromotion Center Co., Ltd. (FPC) and the State Key Laboratoryof Light Alloys Casting Technologies for High-end Equipment.
基金Project(2011-0004048)supported by National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology
文摘The new magnetic-assisted abrasive polishing process for non-ferrous materials was proposed in order to increase the magnetic flux density which directly influences the contact force between the workpiece and the abrasives.The permanent magnets were installed under the workpiece and their effects were verified by the experiments.The effect of polishing factors on the improvement of surface roughness was evaluated based on the Taguchi experimental method,and the optimal conditions for polishing AISI316 stainless steel were determined.The predicting model for improving surface roughness was developed and the validity of the developed model was tested.The results show that the permanent magnets are very useful in improving the surface roughness in the magnetic-assisted abrasive polishing process.
基金The project was finaneially supported by the National Natural Sciencc Foundation of China
文摘Our research and investigation proves thatthe growth rate of the productivity of thenonferrous metals industry is much lower thanthat of investment,and that the potential for in-creasing productivity iS very grear,in spite of thecompplicated influence of multiple weak joints re-strieting the increase of the productivity.To solvethese problems,following policies should
文摘The definition of a plain bearing is given.The requirements for bearing materials are pro-posed.The historical perspective and recent development of the bearing materials are intro-duced,and the performances of current bearing materials are
基金The project was financially supported by the Chima National Natural Science Foundation
文摘The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of improving the productivity of the nonferrous metals industry have been discussed.
文摘Founded in January of 1984,China National Nonferrous Metals Import and Export Corporation(CNIEC)is a combined industrial and trading subsidiary of China National Nonferrous Metals Industry Corporation(CNNC).Established in part as a result of China's economic reforms and open door policies,it aims to better utilize the resources and finances of both the domestic and overseas markets to develop China's nonferrous metals industry.Two of CNIEC's most important objectives are to regulate state economic and trade activities within the nonferrous metals industry and to actively compete in the international market through the importation and exportation of nonferrous metals commodities equipment and technology.
文摘The outbreak of COVID-19 early this year has accelerated the industry reshuffle.It is a critical period for companies to think about a long-term development strategy,optimize supply chains,and promote innovation-driven development.In the theme of "Digitalization Application and Intelligent Development in High-Efficient Die Casting Manufacturing",the event this year gathered 262 exhibitors from 9 countries and regions,among which international exhibitors account for 21%,and 11,986 trade visitors working in nonferrous,die casting and related application fields.
文摘China Nonferrous Metals Scientific and Technical Joint-Development Group(CNJDG)consists of thirty odd research,design institutions,universities,colleges,plants,mines,enterprisesand consulting companies(see attached list of membership units)CNJDG has a business executive organization—Nonferrous Metals Scientific and TechnicalDevelopment Corporation(NSTDC)to suit client’s convenience.
文摘This paper introduces the refractories used in various nonferrous metal smelting equipment in China and the existing problems, and puts forward suggestions on the material of refractories, application of new technologies and production management of refractories, etc.