China’s aluminum processing industry showed differentiation,resulting in the unbalanced allocation of profits in domestic aluminum processing enterprises in 2016.Among them,the medium and low-end deep processing ente...China’s aluminum processing industry showed differentiation,resulting in the unbalanced allocation of profits in domestic aluminum processing enterprises in 2016.Among them,the medium and low-end deep processing enterprises saw a profit decline,while high-end enterprises were the other case.Due to a lack of R&D investment in展开更多
The Baise Municipal Government held a commencement ceremony for Baise Mining Group’s1-million-ton deep aluminum processing project('Project')at its base in the Poverty Alleviation Industrial Park in Pingguo C...The Baise Municipal Government held a commencement ceremony for Baise Mining Group’s1-million-ton deep aluminum processing project('Project')at its base in the Poverty Alleviation Industrial Park in Pingguo County.It’s learnt that the Project includes an annual450,000-ton medium and thick plates and plate belts for transportation project,an annual 160。展开更多
Tsinghua-TOYO Research and Development Center of Magnesium and Aluminum Alloys Processing Technology was officially established between Tsinghua University and TOYO Machinery & Metal Co. on Feb. 26, 2002, which is...Tsinghua-TOYO Research and Development Center of Magnesium and Aluminum Alloys Processing Technology was officially established between Tsinghua University and TOYO Machinery & Metal Co. on Feb. 26, 2002, which is a non-independent legal research organization located in Department of Mechanical Engineering of Tsinghua University. The center was equipped with one set of 650t automatic magnesium and aluminum alloys diecasting machine and necessary accessories including the melting furnaces for magnesium alloys and aluminum alloys, an accurate magnesium pump to transfer the magnesium alloys to the shot sleeve of the die casting machine, a die temperature controller, and data logging systems for cavity pressure and die temperature distributions, etc. The center is aimed to the research and development of magnesium and aluminum die casting process and their related technologies, and the main research contents include:展开更多
A transient three-dimensional（3 D） model was established to understand the bubble motion in an industrial electrolytic process. An anode with a new design was tested. It incorporates two slots that allow an efficien...A transient three-dimensional（3 D） model was established to understand the bubble motion in an industrial electrolytic process. An anode with a new design was tested. It incorporates two slots that allow an efficient removal of gas bubbles. The electromagnetic fields were described by solving Maxwell＇s equations. The bubble movement was studied with two-way coupling Euler-Lagrange approach. The interplay of current density and bubble nucleation rate was included. The collision and coalescence of bubbles were considered. Random walk module was invoked for involving the chaotic effect of the turbulence. The numerical results were validated by experimental measurements. The results indicate that the current distribution and the bubble nucleation periodically change. Due to the slot, the bubble elimination heavily increases. The contribution of the slot to the bubble removal exceeds 50% in the case of three currents, and the promotion of the slot decays with increasing the current.展开更多
In order to intensify the leaching process of rare earth（RE） and reduce the impurities in the leachate, ammonium chloride（NH4Cl） and ammonium nitrate（NH4NO3） were mixed as a compound leaching agent to treat the ...In order to intensify the leaching process of rare earth（RE） and reduce the impurities in the leachate, ammonium chloride（NH4Cl） and ammonium nitrate（NH4NO3） were mixed as a compound leaching agent to treat the weathered crust elution-deposited RE ore. Effects of molar ratio of NH~＋_4Cl and NH_4NO_3, ammonium（NH_4） concentration, leaching agent pH and flow rate on the leaching process of RE were studied and evaluated by the chromatographic plate theory. Leaching process of the main impurity aluminium（Al） was also discussed in detail. Results showed that a higher initial ammonium concentration in a certain range could enhance the mass transfer process of RE and Al by providing a driving force to overcome the resistance of diffusion. pH almost had no effects on the mass transfer efficiency of RE and Al in the range of 4 to 8. The relationship between the flow rate and height equivalent to a theoretical plate（HETP） could fit well with the Van Deemter equation, and the flow rate at the lowest HETP was determined. The optimum conditions of column leaching for RE and Al were 1：1（molar ratio） of NH_4Cl and NH_4NO_3, 0.2 mol/L of ammonium concentration, pH 4–8 of leaching agent and 0.5 mL /min of flow rate. Under this condition, the mass transfer efficiency of RE was improved, but no change was observed for Al compared with the most widely used ammonium sulfate. Moreover, the significant difference value（around 20 mL） of retention volume at the peak concentration between RE and Al provided a possibility for their separation. It suggested the potential application of the novel compound leaching agent（NH_4Cl/NH_4NO_3）. It was found that the relative concentration of RE in the leachate could be easily obtained by monitoring the pH of leachate.展开更多
To gain a deep insight into the hot drawing process of aluminum alloy sheet, simulations of cylindrical cup drawing at elevated temperatures were carried out with experimental validation. The influence of four importa...To gain a deep insight into the hot drawing process of aluminum alloy sheet, simulations of cylindrical cup drawing at elevated temperatures were carried out with experimental validation. The influence of four important process parameters, namely,punch velocity, blank holder force(BHF), friction coefficient and initial forming temperature of blank on drawing characteristics(i.e.minimum thickness and thickness deviation) was investigated with the help of design of experiments(DOE), analysis of variance(ANOVA) and analysis of mean(ANOM). Based on the results of ANOVA, it is shown that the blank holder force has the greatest influence on minimum thickness. The importance of punch velocity for thickness deviation is 44.35% followed by BHF of 24.88%,friction coefficient of 15.77% and initial forming temperature of blank of 14.995%. After determining the significance of each factor on forming characteristics, how the individual parameter affects characteristics was further analyzed by ANOM.展开更多
Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction a...Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.展开更多
This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.th...This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.the surface morphology and chemical groups）of plasma modified aluminum significantly depends on the chemical precleaning.Commonly used chemicals（isopropanol,trichlorethane,solution of Na OH in deionized water）were used as precleaning agents.The plasma treatments were done using a radio frequency driven atmospheric pressure plasma pencil developed at Masaryk University,which operates in Ar,Ar/O_2 gas mixtures.The effectiveness of the plasma treatment was estimated by the wettability measurements,showing high wettability improvement already after 0.3 s treatment.The effects of surface cleaning（hydrocarbon removal）,surface oxidation and activation（generation of OH groups）were estimated using infrared spectroscopy.The changes in the surface morphology were measured using scanning electron microscopy.Optical emission spectroscopy measurements in the near-to-surface region with temperature calculations showed that plasma itself depends on the sample precleaning procedure.展开更多
The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated. The results indicated that the deformation process homogenized microstructure a...The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated. The results indicated that the deformation process homogenized microstructure and improved mechanical properties of the A356 aluminum alloy. During the hot spinning process, eutectic Si particles and Fe-rich phases were fragmented, and porosities were eliminated. In addition, recrystallization of Al matrix and precipitation of Al Si Ti phases occurred. The mechanical property testing results indicated that there was a significant increase of ductility and a decrease of average microhardness in deformed alloy over die-cast alloy. This is attributed to uniform distribution of finer spherical eutectic Si particles, the elimination of casting defects and to the recrystallized finer grain structure.展开更多
At the end of August,Chinalco Southeast Coast Aluminum Deep Processing Base broke ground at the Fujian-Taiwan(Fuzhou)Industrial Park for Blue Economy.Based on Chilco Ruimin(an aluminum processing subsidiary of Chinalc...At the end of August,Chinalco Southeast Coast Aluminum Deep Processing Base broke ground at the Fujian-Taiwan(Fuzhou)Industrial Park for Blue Economy.Based on Chilco Ruimin(an aluminum processing subsidiary of Chinalco in Fujian Province)as the main body,Chinalco展开更多
The kinetic behaviour of aluminum naphthenate/benzene system in the process of gela- tion and degradation wag systematically studied. The results obtained from the kinetic experiments indicated that the gelation stage...The kinetic behaviour of aluminum naphthenate/benzene system in the process of gela- tion and degradation wag systematically studied. The results obtained from the kinetic experiments indicated that the gelation stage was in accordance with a. kinetic model of an auto-catalytic first-order reaction, and the degradation stage was a simple first-order reaction. The rate constants in these two stages at various temperaturs were measured. And the determined apparent activation energies for the gelation stage and for the degradation stage are 27.5±2.0 and 37.7±2.3 kJ/mol, respectively.展开更多
This paper presents a new intelligent control method based on intelligent characteristic model for a kind of complicated plant with nonlinearities and uncertainties, whose controlled output variables cannot be measure...This paper presents a new intelligent control method based on intelligent characteristic model for a kind of complicated plant with nonlinearities and uncertainties, whose controlled output variables cannot be measured on line continuously. The basic idea of this method is to utilize intelligent techniques to form the characteristic model of the controlled plant according to the principle of combining the characteristics of the plant with the control requirements, and then to present a new design method of intelligent controller based on this characteristic model. First, the modeling principles and expression of the intelligent characteristic model are presented. Then based on description of the intelligent characteristic model, the design principles and methods of the intelligent controller composed of several open-loops and closed-loops sub controllers with qualitative and quantitative information are given. Finally, the application of this method in alumina concentration control in the real aluminum electrolytic process is introduced. It is proved in practice that the above methods not only are easy to implement in engineering design but also avoid the trial-and-error of general intelligent controllers. It has taken better effect in the following application: achieving long-term stable control of low alumina concentration and increasing the controlled ratio of anode effect greatly from 60% to 80%.展开更多
文摘China’s aluminum processing industry showed differentiation,resulting in the unbalanced allocation of profits in domestic aluminum processing enterprises in 2016.Among them,the medium and low-end deep processing enterprises saw a profit decline,while high-end enterprises were the other case.Due to a lack of R&D investment in
文摘The Baise Municipal Government held a commencement ceremony for Baise Mining Group’s1-million-ton deep aluminum processing project('Project')at its base in the Poverty Alleviation Industrial Park in Pingguo County.It’s learnt that the Project includes an annual450,000-ton medium and thick plates and plate belts for transportation project,an annual 160。
文摘Tsinghua-TOYO Research and Development Center of Magnesium and Aluminum Alloys Processing Technology was officially established between Tsinghua University and TOYO Machinery & Metal Co. on Feb. 26, 2002, which is a non-independent legal research organization located in Department of Mechanical Engineering of Tsinghua University. The center was equipped with one set of 650t automatic magnesium and aluminum alloys diecasting machine and necessary accessories including the melting furnaces for magnesium alloys and aluminum alloys, an accurate magnesium pump to transfer the magnesium alloys to the shot sleeve of the die casting machine, a die temperature controller, and data logging systems for cavity pressure and die temperature distributions, etc. The center is aimed to the research and development of magnesium and aluminum die casting process and their related technologies, and the main research contents include:
基金Project(51434005) supported by the National Natural Science Foundation of China
文摘A transient three-dimensional（3 D） model was established to understand the bubble motion in an industrial electrolytic process. An anode with a new design was tested. It incorporates two slots that allow an efficient removal of gas bubbles. The electromagnetic fields were described by solving Maxwell＇s equations. The bubble movement was studied with two-way coupling Euler-Lagrange approach. The interplay of current density and bubble nucleation rate was included. The collision and coalescence of bubbles were considered. Random walk module was invoked for involving the chaotic effect of the turbulence. The numerical results were validated by experimental measurements. The results indicate that the current distribution and the bubble nucleation periodically change. Due to the slot, the bubble elimination heavily increases. The contribution of the slot to the bubble removal exceeds 50% in the case of three currents, and the promotion of the slot decays with increasing the current.
基金Project supported by the National Natural Science Foundation of China(51274152 and 41472071)the Program for Excellent Young Scientific and Technological Innovation Team of Hubei Provincial Department of Education,China(T201506)
文摘In order to intensify the leaching process of rare earth（RE） and reduce the impurities in the leachate, ammonium chloride（NH4Cl） and ammonium nitrate（NH4NO3） were mixed as a compound leaching agent to treat the weathered crust elution-deposited RE ore. Effects of molar ratio of NH~＋_4Cl and NH_4NO_3, ammonium（NH_4） concentration, leaching agent pH and flow rate on the leaching process of RE were studied and evaluated by the chromatographic plate theory. Leaching process of the main impurity aluminium（Al） was also discussed in detail. Results showed that a higher initial ammonium concentration in a certain range could enhance the mass transfer process of RE and Al by providing a driving force to overcome the resistance of diffusion. pH almost had no effects on the mass transfer efficiency of RE and Al in the range of 4 to 8. The relationship between the flow rate and height equivalent to a theoretical plate（HETP） could fit well with the Van Deemter equation, and the flow rate at the lowest HETP was determined. The optimum conditions of column leaching for RE and Al were 1：1（molar ratio） of NH_4Cl and NH_4NO_3, 0.2 mol/L of ammonium concentration, pH 4–8 of leaching agent and 0.5 mL /min of flow rate. Under this condition, the mass transfer efficiency of RE was improved, but no change was observed for Al compared with the most widely used ammonium sulfate. Moreover, the significant difference value（around 20 mL） of retention volume at the peak concentration between RE and Al provided a possibility for their separation. It suggested the potential application of the novel compound leaching agent（NH_4Cl/NH_4NO_3）. It was found that the relative concentration of RE in the leachate could be easily obtained by monitoring the pH of leachate.
基金Project(2009ZX04014-074)supported by the National High Technology Research and Development Program of ChinaProject(20120006110017)supported by Doctoral Fund Program of Ministry of Education of ChinaProject(P2014-15)supported by State Key Laboratory of Materials Processing and Die & Mould Technology(Huazhong University of Science and Technology),China
文摘To gain a deep insight into the hot drawing process of aluminum alloy sheet, simulations of cylindrical cup drawing at elevated temperatures were carried out with experimental validation. The influence of four important process parameters, namely,punch velocity, blank holder force(BHF), friction coefficient and initial forming temperature of blank on drawing characteristics(i.e.minimum thickness and thickness deviation) was investigated with the help of design of experiments(DOE), analysis of variance(ANOVA) and analysis of mean(ANOM). Based on the results of ANOVA, it is shown that the blank holder force has the greatest influence on minimum thickness. The importance of punch velocity for thickness deviation is 44.35% followed by BHF of 24.88%,friction coefficient of 15.77% and initial forming temperature of blank of 14.995%. After determining the significance of each factor on forming characteristics, how the individual parameter affects characteristics was further analyzed by ANOM.
基金Project(2010AA065201)supported by the High Technology Research and Development Program of ChinaProject(2013zzts038)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(ZB2011CBBCe1)supported by the Major Program for Aluminum Corporation of China Limited,China
文摘Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.
基金the Czech Science Foundation(Project No.104/08/02290)the Czech Ministry of Industry and Trade(Project CZ.1.03/5.1.00/12.00010)the Czech Ministry of Education(Project MSM0021622411)
文摘This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.the surface morphology and chemical groups）of plasma modified aluminum significantly depends on the chemical precleaning.Commonly used chemicals（isopropanol,trichlorethane,solution of Na OH in deionized water）were used as precleaning agents.The plasma treatments were done using a radio frequency driven atmospheric pressure plasma pencil developed at Masaryk University,which operates in Ar,Ar/O_2 gas mixtures.The effectiveness of the plasma treatment was estimated by the wettability measurements,showing high wettability improvement already after 0.3 s treatment.The effects of surface cleaning（hydrocarbon removal）,surface oxidation and activation（generation of OH groups）were estimated using infrared spectroscopy.The changes in the surface morphology were measured using scanning electron microscopy.Optical emission spectroscopy measurements in the near-to-surface region with temperature calculations showed that plasma itself depends on the sample precleaning procedure.
基金supported by the National Key Research Project(No.2016YFB0300901)
文摘The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated. The results indicated that the deformation process homogenized microstructure and improved mechanical properties of the A356 aluminum alloy. During the hot spinning process, eutectic Si particles and Fe-rich phases were fragmented, and porosities were eliminated. In addition, recrystallization of Al matrix and precipitation of Al Si Ti phases occurred. The mechanical property testing results indicated that there was a significant increase of ductility and a decrease of average microhardness in deformed alloy over die-cast alloy. This is attributed to uniform distribution of finer spherical eutectic Si particles, the elimination of casting defects and to the recrystallized finer grain structure.
文摘At the end of August,Chinalco Southeast Coast Aluminum Deep Processing Base broke ground at the Fujian-Taiwan(Fuzhou)Industrial Park for Blue Economy.Based on Chilco Ruimin(an aluminum processing subsidiary of Chinalco in Fujian Province)as the main body,Chinalco
基金This project was supported by the National Natural Science Foundation of China.
文摘The kinetic behaviour of aluminum naphthenate/benzene system in the process of gela- tion and degradation wag systematically studied. The results obtained from the kinetic experiments indicated that the gelation stage was in accordance with a. kinetic model of an auto-catalytic first-order reaction, and the degradation stage was a simple first-order reaction. The rate constants in these two stages at various temperaturs were measured. And the determined apparent activation energies for the gelation stage and for the degradation stage are 27.5±2.0 and 37.7±2.3 kJ/mol, respectively.
基金supported by the National Natural Science Foundation of China(Grant No.60034010)
文摘This paper presents a new intelligent control method based on intelligent characteristic model for a kind of complicated plant with nonlinearities and uncertainties, whose controlled output variables cannot be measured on line continuously. The basic idea of this method is to utilize intelligent techniques to form the characteristic model of the controlled plant according to the principle of combining the characteristics of the plant with the control requirements, and then to present a new design method of intelligent controller based on this characteristic model. First, the modeling principles and expression of the intelligent characteristic model are presented. Then based on description of the intelligent characteristic model, the design principles and methods of the intelligent controller composed of several open-loops and closed-loops sub controllers with qualitative and quantitative information are given. Finally, the application of this method in alumina concentration control in the real aluminum electrolytic process is introduced. It is proved in practice that the above methods not only are easy to implement in engineering design but also avoid the trial-and-error of general intelligent controllers. It has taken better effect in the following application: achieving long-term stable control of low alumina concentration and increasing the controlled ratio of anode effect greatly from 60% to 80%.
