Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for produci...Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite （fixed carbon, 99%） as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.展开更多
A new process of directly smelting boron steel from boron-containing pig iron has been established. The starting material boron-containing pig iron was obtained from ludwigite ore, which is very abundant in the easter...A new process of directly smelting boron steel from boron-containing pig iron has been established. The starting material boron-containing pig iron was obtained from ludwigite ore, which is very abundant in the eastern area of Liaoning Province of China. The experiment was performed in a medium frequency induction furnace, and Fe2O3 powder was used as the oxidizing agent. The effects of temperature, addition of Fe2O3, basicity, stirring, and composition of melt on the oxidation of silicon and boron were investigated respectively. The results showed that sili- con and boron were oxidized simultaneously and their oxidation ratio exceeded 90% at 1 400℃. The favorable oxidation temperature of silicon was about 1 300-- 1 350℃. High oxygen potential of slag and strong stirring enhanced the oxidation of silicon and boron.展开更多
A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achie...A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achievedafter the wastes were smelted at1575°C for20min under C/Fe molar ratio of1.6and basicity of1.2.The produced pig iron could beused in steel-making.This study provides a way for recycling iron from smelting slag and hydrometallurgical residue.展开更多
The large quantity of sediment produced in the hearth during vanadium titano-magnetite smelting in a blast furnace(BF)affects the stability of the blast furnace operation.Testing and analysis of the sediment in the he...The large quantity of sediment produced in the hearth during vanadium titano-magnetite smelting in a blast furnace(BF)affects the stability of the blast furnace operation.Testing and analysis of the sediment in the hearth of Chengde Iron and Steel Company?s BF No.7 revealed that it was mainly concentrated in the location below the tuyere and above the iron notch.Notably,some of the bonding material(sediment)consisted of greater than 50%pig iron,and the pig iron distributed in the slag was granular.It is proposed that a large quantity of Ti C and Ti(C,N)are deposited on the surface of the pig iron.These high melting point materials mix with iron drops,preventing the slag from flowing freely,thus leading to the formation of bonding materials.In addition,the viscosity and melting temperature of the slag in the tuyere areas fluctuate greatly,and thus the properties of the slag are unstable.Moreover,the slag contains large quantities of carbon,which results in the reduction of Ti O2.The resultant precipitation of Ti is followed by the formation of Ti C in the slag,which also leads to an increase in the viscosity of the slag and difficulty in achieving separation of the slag-iron.In fact,all of these factors interact with each other,and as a result,sediment is formed when the operating conditions in the hearth fluctuate.展开更多
As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China＇ s...As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China＇ s current blast furnace method of producing pig low Ni iron with laterite, this study analyzed the technical characteristics and relevant problems of this process based on the discussion on the characteristics of laterite. The study aims to provide a reference for the better use of laterite in China.展开更多
A two-stage oxidation—alkali leaching—acid leaching method was proposed to recovery Fe,V,and Ti in modified Ti-bearing blast furnace slag.The optimal experiment conditions of iron extraction were one-stage oxidation...A two-stage oxidation—alkali leaching—acid leaching method was proposed to recovery Fe,V,and Ti in modified Ti-bearing blast furnace slag.The optimal experiment conditions of iron extraction were one-stage oxidation time 40 s and holding time 8 min.The recovery rate of iron was 89.93%.The optimum experiment conditions of vanadium extraction were total oxidation time of 126 s,NaOH concentration of 4.0 mol/L,leaching temperature of 95℃,leaching time of 90 min,and the number of cycle was 4.The leaching rate of vanadium was 92.13%.The optimal experiment conditions of titanium extraction were HCl concentration of 4.5 mol/L,leaching temperature of 75℃,and leaching time of 90 min.The TiO_(2)content of synthetic rutile was 98.61%.展开更多
In order to solve the problem of the shortage of scrap, especially high quality scrap, granular pig iron, a new substitute for scrap or DRI (direct reduction iron) has been developed. The technical process of decarbon...In order to solve the problem of the shortage of scrap, especially high quality scrap, granular pig iron, a new substitute for scrap or DRI (direct reduction iron) has been developed. The technical process of decarbonized granular pig iron has been evaluated. The result shows that this new process is superior to direct reduction process in product quality, construction investment, operation flexibility, production efficiency etc. Decarbonized granular pig iron (DGPI) not only can be used as conventional scrap but also can be charged into EAF as high purity burden equivalent to heavy scrap.展开更多
In the metallurgical industries, it is very important to characterize the flow of molten metals in open channels given that they are transported through these devices to different plant sections. Howeve...In the metallurgical industries, it is very important to characterize the flow of molten metals in open channels given that they are transported through these devices to different plant sections. However, unlike the flow of water which has been studied since ancient times, the flow of molten metals in open channels has received little attention. The unsteady non-uniform flow of blast furnace molten pig iron in a rectangular open channel is analyzed in this work by numerical solution of the Saint-Venant equations. The influence of mesh size on the convergence of molten metal height is studied to determine the proper mesh and time step sizes. A sinusoidal inflow pulse is imposed at the entrance of the channel in order to analyze the propagation of the resulting wave. The influence of the angle of inclination of the channel and the roughness coefficient of the walls on the amplitude and the dynamic behavior of the height of the molten metal are analyzed. Phase portraits of the channel state variables are constructed and interpreted. Numerical simulations show that as the angle of inclination of the channel increases, the amplitude of the formed wave decreases. From 10 degrees onwards, the peak of the wave descends even below the initial height. On the other hand, the roughness coefficient affects the molten pig iron height profiles in an inverse way than the angle of inclination. The amplitude of the formed wave increases as the roughness coefficient increases.展开更多
文摘Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite （fixed carbon, 99%） as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.
基金Item Sponsored by National Natural Science Foundation of China and Shanghai Baosteel Group Corporation (50374024) Hi-Tech Research and Development Programof China (2006AA03Z529)
文摘A new process of directly smelting boron steel from boron-containing pig iron has been established. The starting material boron-containing pig iron was obtained from ludwigite ore, which is very abundant in the eastern area of Liaoning Province of China. The experiment was performed in a medium frequency induction furnace, and Fe2O3 powder was used as the oxidizing agent. The effects of temperature, addition of Fe2O3, basicity, stirring, and composition of melt on the oxidation of silicon and boron were investigated respectively. The results showed that sili- con and boron were oxidized simultaneously and their oxidation ratio exceeded 90% at 1 400℃. The favorable oxidation temperature of silicon was about 1 300-- 1 350℃. High oxygen potential of slag and strong stirring enhanced the oxidation of silicon and boron.
基金Project(51574295) supported by the National Natural Science Foundation of ChinaProject(2014FJ1011) supported by the Key Project of Science and Technology of Hunan Province,China+1 种基金Project(2012GS430201) supported by the Science and Technology Program for Public Wellbeing,ChinaProject supported by the Co-Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
文摘A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achievedafter the wastes were smelted at1575°C for20min under C/Fe molar ratio of1.6and basicity of1.2.The produced pig iron could beused in steel-making.This study provides a way for recycling iron from smelting slag and hydrometallurgical residue.
基金Item Sponsored by National Natural Science Foundation of China(U1360205)
文摘The large quantity of sediment produced in the hearth during vanadium titano-magnetite smelting in a blast furnace(BF)affects the stability of the blast furnace operation.Testing and analysis of the sediment in the hearth of Chengde Iron and Steel Company?s BF No.7 revealed that it was mainly concentrated in the location below the tuyere and above the iron notch.Notably,some of the bonding material(sediment)consisted of greater than 50%pig iron,and the pig iron distributed in the slag was granular.It is proposed that a large quantity of Ti C and Ti(C,N)are deposited on the surface of the pig iron.These high melting point materials mix with iron drops,preventing the slag from flowing freely,thus leading to the formation of bonding materials.In addition,the viscosity and melting temperature of the slag in the tuyere areas fluctuate greatly,and thus the properties of the slag are unstable.Moreover,the slag contains large quantities of carbon,which results in the reduction of Ti O2.The resultant precipitation of Ti is followed by the formation of Ti C in the slag,which also leads to an increase in the viscosity of the slag and difficulty in achieving separation of the slag-iron.In fact,all of these factors interact with each other,and as a result,sediment is formed when the operating conditions in the hearth fluctuate.
文摘As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China＇ s current blast furnace method of producing pig low Ni iron with laterite, this study analyzed the technical characteristics and relevant problems of this process based on the discussion on the characteristics of laterite. The study aims to provide a reference for the better use of laterite in China.
基金financial support from the National Science and Technology Support Program of China(No.2015BAB18B00)。
文摘A two-stage oxidation—alkali leaching—acid leaching method was proposed to recovery Fe,V,and Ti in modified Ti-bearing blast furnace slag.The optimal experiment conditions of iron extraction were one-stage oxidation time 40 s and holding time 8 min.The recovery rate of iron was 89.93%.The optimum experiment conditions of vanadium extraction were total oxidation time of 126 s,NaOH concentration of 4.0 mol/L,leaching temperature of 95℃,leaching time of 90 min,and the number of cycle was 4.The leaching rate of vanadium was 92.13%.The optimal experiment conditions of titanium extraction were HCl concentration of 4.5 mol/L,leaching temperature of 75℃,and leaching time of 90 min.The TiO_(2)content of synthetic rutile was 98.61%.
文摘In order to solve the problem of the shortage of scrap, especially high quality scrap, granular pig iron, a new substitute for scrap or DRI (direct reduction iron) has been developed. The technical process of decarbonized granular pig iron has been evaluated. The result shows that this new process is superior to direct reduction process in product quality, construction investment, operation flexibility, production efficiency etc. Decarbonized granular pig iron (DGPI) not only can be used as conventional scrap but also can be charged into EAF as high purity burden equivalent to heavy scrap.
文摘In the metallurgical industries, it is very important to characterize the flow of molten metals in open channels given that they are transported through these devices to different plant sections. However, unlike the flow of water which has been studied since ancient times, the flow of molten metals in open channels has received little attention. The unsteady non-uniform flow of blast furnace molten pig iron in a rectangular open channel is analyzed in this work by numerical solution of the Saint-Venant equations. The influence of mesh size on the convergence of molten metal height is studied to determine the proper mesh and time step sizes. A sinusoidal inflow pulse is imposed at the entrance of the channel in order to analyze the propagation of the resulting wave. The influence of the angle of inclination of the channel and the roughness coefficient of the walls on the amplitude and the dynamic behavior of the height of the molten metal are analyzed. Phase portraits of the channel state variables are constructed and interpreted. Numerical simulations show that as the angle of inclination of the channel increases, the amplitude of the formed wave decreases. From 10 degrees onwards, the peak of the wave descends even below the initial height. On the other hand, the roughness coefficient affects the molten pig iron height profiles in an inverse way than the angle of inclination. The amplitude of the formed wave increases as the roughness coefficient increases.
