A multi-objective optimization and analysis model of the sintering process based on BP neural network is presented. Genetic algorithms are combined to simplify the BP neural network, which can reduce the learning time...A multi-objective optimization and analysis model of the sintering process based on BP neural network is presented. Genetic algorithms are combined to simplify the BP neural network, which can reduce the learning time and increase the forecasting accuracy of the network model. This model has been experimented in the sintering process, and the production cost, the energy consumption, the quality （revolving intensity）, and the output are considered at the same time. Moreover, the relation between some factors and the multi-objectives has been analyzed, and the results are consistent with the process. Different objectives are emphasized at different practical periods, and this can provide a theoretical basis for the manager.展开更多
A multi-fluid blast furnace model was simply introduced and was used to simulate several innovative ironmaking operations. The simulation results show that injecting hydrogen bearing materials, especially injecting na...A multi-fluid blast furnace model was simply introduced and was used to simulate several innovative ironmaking operations. The simulation results show that injecting hydrogen bearing materials, especially injecting natural gas and plastics, the hydrogen reduction is enhanced, and the furnace performance is improved simultaneously. Total heat input shows obvious decrease due to the decrease of heat consumption in direct reduction, solution loss and silicon transfer reactions. If carbon composite agglomerates are charged into the furnace, the temperature of thermal reserve zone will obviously decrease, and the reduction of iron-bearing burden materials will be retarded. However, the efficiency of blast furnace is improved just due to the decrease in heat requirements for solution loss, sinter reduction, and silicon transfer reactions, and less heat loss through top gas and furnace wall. Finally, the model is used to investigate the performance of blast furnace under the condition of top gas recycling together with plastics injection, cold oxygen blasting and carbon composite agglomerate charging. The lower furnace temperature, extremely accelerated reduction rate, drastically decreased CO2 emission and remarkably enhanced heat efficiency were obtained by using the innovative operations, and the blast furnace operation with superhigh efficiency can be realized.展开更多
以不同质量分数的Mg O烧结矿为原料,考察了Mg O质量分数以及矿焦混装对熔化温度、熔化区间以及最大压差的影响,并对熔化温度的变化进行了理论分析.研究表明:当烧结矿中Mg O质量分数由1.3%增加至2.0%时,熔化开始温度基本不变,熔化终了温...以不同质量分数的Mg O烧结矿为原料,考察了Mg O质量分数以及矿焦混装对熔化温度、熔化区间以及最大压差的影响,并对熔化温度的变化进行了理论分析.研究表明:当烧结矿中Mg O质量分数由1.3%增加至2.0%时,熔化开始温度基本不变,熔化终了温度升高,熔化区间(tD-tS)由156℃增加到207℃,最大压差Δpmax由10 k Pa增加到11 k Pa;当w(Mg O)=2.0%,且烧结矿与矿焦混装时,熔化开始温度由1 312℃增加到1 324℃,熔化终了温度由1 519℃降低到1 480℃,熔化区间tD-tS由207℃降低到156℃,最大压差Δpmax由11 k Pa降低到7 k Pa,故使用矿焦混装可改善高炉熔滴性能.展开更多
The reducibility of iron-bearing burdens was emphasized for improving the operation efficiency of blast furnace. The blast furnace operation of charging the burdens with high reducibility has been numerically evaluate...The reducibility of iron-bearing burdens was emphasized for improving the operation efficiency of blast furnace. The blast furnace operation of charging the burdens with high reducibility has been numerically evaluated using a multi-fluid blast furnace model. The effects of reaction rate constants and diffusion coefficients were investigated separately or simultaneously for clarifying the variations of furnace state. According to the model simulation results, in the upper zone, the indirect reduction of the burdens proceeds at a faster rate and the shaft efficiency is enhanced with the improvement under the conditions of interface reaction and intra-particle diffusion. In the lower zone, direct reduction in molten slag is restrained. As a consequence, CO utilization of top gas is enhanced and the ratio of direct reduction is decreased. It is possible to achieve higher energy efficiency of the blast furnace, and this is represented by the improvement in productivity and the decrease in consumption of reducing agent. The use of high-reducibility burdens contributes to a better performance of blast furnace. More efforts are necessary to develop and apply highreducibility sinter and carbon composite agglomerates for practical application at a blast furnace.展开更多
In order to provide a reliable reference for utilizing Indonesia vanadium titano-magnetite(VTM) in blast furnace(BF) economically, metallurgical properties of iron ore sinter with addition of Indonesia VTM in mixed si...In order to provide a reliable reference for utilizing Indonesia vanadium titano-magnetite(VTM) in blast furnace(BF) economically, metallurgical properties of iron ore sinter with addition of Indonesia VTM in mixed sintering materials were investigated, including low-temperature reduction degradation index(RDI), reducibility index(RI), and softening/melting properties. Additionally, influenced mechanism of Indonesia VTM on metallurgical properties of sinter was studied. It is found that adding Indonesia VTM in sintering process quickly increases the RDI of sinters, and decreases the RI from 78.02% to 68.43%. Moreover, both beginning temperature(T_4) and final temperature(TD) of softening/melting increase gradually, and cohesive zone temperature range(T_D–T_4) enlarges from 219 oC to 315 oC. As a result, the permeability of cohesive zone gets worse, which is proven by the higher maximum pressure drop(δPmax) in softening/melting experiments. It is concluded that, after comprehensively considering all metallurgical properties mentioned above, the proper proportion of Indonesia VTM in sintering process is proposed in the new raw materials conditions.展开更多
As a main charging form of BF （blast furnace）, pellets play an important role in blast furnace process. However, comparing with sinters, pellets have many disadvantages, such as reduction swelling, low softening and...As a main charging form of BF （blast furnace）, pellets play an important role in blast furnace process. However, comparing with sinters, pellets have many disadvantages, such as reduction swelling, low softening and melting temperature and so on. Therefore, the flux pellets have been applied in blast furnace widely, especially MgO containing pellets. The light burned magnesite is applied as MgO containing additive in pellet production. The char- acters of light burned magnesite are explored. Meanwhile, the effects of it on low-temperature metallurgical proper-ties are investigated such as low-temperature reduction degradation index （RDI）, compressive strength （CS） and the reduction swelling index （RSI）. The light burned magnesite calcined at 850 ℃ manifests better grindability, larger specific surface area, and higher hydration activity. It is found that the addition of light burned magnesite can im- prove low-temperature metallurgical properties （RDI, RSI） of the pellets. With the increase of light burned magne-site in pellets, the RSI and RDI decrease gradually; when the proportion of light burned magnesite does not exceed 2.0% in pellets, the CS decreases slightly, but it still surnasses 2689 N. which can still meet the demand of BF.展开更多
According to the axisymmetric heat conduction of monolayer cylinder, a general method was deduced to calculate the axisymmetric temperature of linear heat conduction multilayer cylinder. Four types of boundary conditi...According to the axisymmetric heat conduction of monolayer cylinder, a general method was deduced to calculate the axisymmetric temperature of linear heat conduction multilayer cylinder. Four types of boundary conditions were summarized and formulas for each type were derived. Then, a general calculating program was developed. Four temperature formulas could be expressed by a uniform equation, and the intermediate interface temperatures of axisymmetrical linear conduction multilayer cylinder satisfied tridiagonal linear and nonlinear systems of equations, which could be solved with the pursuit method and the Newton＇s method, respectively. With the calculating program, the temperature at any point of linear heat conduction multilayer cylinder could be obtained.展开更多
The granule size distribution and the porosity of the granule packing process were researched. For realizing the optimizing control of the whole sintering production process, researchers must know the factors influenc...The granule size distribution and the porosity of the granule packing process were researched. For realizing the optimizing control of the whole sintering production process, researchers must know the factors influencing the granule size distribution and the porosity. Therefore, tests were carried out in the laboratory with regard to the influences of the size and size distribution of raw materials and the total moisture content on the size and size distribution of granule. Moreover, tests for finding out the influences of the moisture content and the granule volume fraction on the porosity were also carried out. The results show that （1） the raw material has little influence on granulation when its size is in the range of 0. 51 mm to 1.0 mm; （2） the influence of the material size on granule size plays a dominant role, and in contrast, the moisture content creates a minor effect on granule size; （3） in binary packing system, with the increase in the constituent volume fraction, the porosity initially increases and then decreases, and there is a minimum value on the porosity curve of the binary mixture system; （4） the minimum value of the porosity in binary packing system occurs at different locations for different moisture contents, and this value shifts from right to left on the porosity curve with increasing the moisture content; （5） the addition of small granules to the same size component cannot create a significant influence on the porosity, whereas the addition of large granules to the same system can greatly change the porosity.展开更多
文摘A multi-objective optimization and analysis model of the sintering process based on BP neural network is presented. Genetic algorithms are combined to simplify the BP neural network, which can reduce the learning time and increase the forecasting accuracy of the network model. This model has been experimented in the sintering process, and the production cost, the energy consumption, the quality （revolving intensity）, and the output are considered at the same time. Moreover, the relation between some factors and the multi-objectives has been analyzed, and the results are consistent with the process. Different objectives are emphasized at different practical periods, and this can provide a theoretical basis for the manager.
基金Projects(51874080,51604069)supported by the National Natural Science Foundation of ChinaProject(N162504004)supported by the Fundamental Research Funds for the Central Universities,China
文摘A multi-fluid blast furnace model was simply introduced and was used to simulate several innovative ironmaking operations. The simulation results show that injecting hydrogen bearing materials, especially injecting natural gas and plastics, the hydrogen reduction is enhanced, and the furnace performance is improved simultaneously. Total heat input shows obvious decrease due to the decrease of heat consumption in direct reduction, solution loss and silicon transfer reactions. If carbon composite agglomerates are charged into the furnace, the temperature of thermal reserve zone will obviously decrease, and the reduction of iron-bearing burden materials will be retarded. However, the efficiency of blast furnace is improved just due to the decrease in heat requirements for solution loss, sinter reduction, and silicon transfer reactions, and less heat loss through top gas and furnace wall. Finally, the model is used to investigate the performance of blast furnace under the condition of top gas recycling together with plastics injection, cold oxygen blasting and carbon composite agglomerate charging. The lower furnace temperature, extremely accelerated reduction rate, drastically decreased CO2 emission and remarkably enhanced heat efficiency were obtained by using the innovative operations, and the blast furnace operation with superhigh efficiency can be realized.
文摘以不同质量分数的Mg O烧结矿为原料,考察了Mg O质量分数以及矿焦混装对熔化温度、熔化区间以及最大压差的影响,并对熔化温度的变化进行了理论分析.研究表明:当烧结矿中Mg O质量分数由1.3%增加至2.0%时,熔化开始温度基本不变,熔化终了温度升高,熔化区间(tD-tS)由156℃增加到207℃,最大压差Δpmax由10 k Pa增加到11 k Pa;当w(Mg O)=2.0%,且烧结矿与矿焦混装时,熔化开始温度由1 312℃增加到1 324℃,熔化终了温度由1 519℃降低到1 480℃,熔化区间tD-tS由207℃降低到156℃,最大压差Δpmax由11 k Pa降低到7 k Pa,故使用矿焦混装可改善高炉熔滴性能.
文摘The reducibility of iron-bearing burdens was emphasized for improving the operation efficiency of blast furnace. The blast furnace operation of charging the burdens with high reducibility has been numerically evaluated using a multi-fluid blast furnace model. The effects of reaction rate constants and diffusion coefficients were investigated separately or simultaneously for clarifying the variations of furnace state. According to the model simulation results, in the upper zone, the indirect reduction of the burdens proceeds at a faster rate and the shaft efficiency is enhanced with the improvement under the conditions of interface reaction and intra-particle diffusion. In the lower zone, direct reduction in molten slag is restrained. As a consequence, CO utilization of top gas is enhanced and the ratio of direct reduction is decreased. It is possible to achieve higher energy efficiency of the blast furnace, and this is represented by the improvement in productivity and the decrease in consumption of reducing agent. The use of high-reducibility burdens contributes to a better performance of blast furnace. More efforts are necessary to develop and apply highreducibility sinter and carbon composite agglomerates for practical application at a blast furnace.
基金Projects(51604069,51604049,U1508213) supported by the National Natural Science Foundation of ChinaProject(N162504004) supported by the Fundamental Research Funds for the Central Universities,ChinaProjects(2017YFB0603800,2017YFB0603801) supported by the National Key R&D Program of China
文摘In order to provide a reliable reference for utilizing Indonesia vanadium titano-magnetite(VTM) in blast furnace(BF) economically, metallurgical properties of iron ore sinter with addition of Indonesia VTM in mixed sintering materials were investigated, including low-temperature reduction degradation index(RDI), reducibility index(RI), and softening/melting properties. Additionally, influenced mechanism of Indonesia VTM on metallurgical properties of sinter was studied. It is found that adding Indonesia VTM in sintering process quickly increases the RDI of sinters, and decreases the RI from 78.02% to 68.43%. Moreover, both beginning temperature(T_4) and final temperature(TD) of softening/melting increase gradually, and cohesive zone temperature range(T_D–T_4) enlarges from 219 oC to 315 oC. As a result, the permeability of cohesive zone gets worse, which is proven by the higher maximum pressure drop(δPmax) in softening/melting experiments. It is concluded that, after comprehensively considering all metallurgical properties mentioned above, the proper proportion of Indonesia VTM in sintering process is proposed in the new raw materials conditions.
基金Item Sponsored by National Natural Science Foundation of China ( 51074206 , 51074040 )
文摘As a main charging form of BF （blast furnace）, pellets play an important role in blast furnace process. However, comparing with sinters, pellets have many disadvantages, such as reduction swelling, low softening and melting temperature and so on. Therefore, the flux pellets have been applied in blast furnace widely, especially MgO containing pellets. The light burned magnesite is applied as MgO containing additive in pellet production. The char- acters of light burned magnesite are explored. Meanwhile, the effects of it on low-temperature metallurgical proper-ties are investigated such as low-temperature reduction degradation index （RDI）, compressive strength （CS） and the reduction swelling index （RSI）. The light burned magnesite calcined at 850 ℃ manifests better grindability, larger specific surface area, and higher hydration activity. It is found that the addition of light burned magnesite can im- prove low-temperature metallurgical properties （RDI, RSI） of the pellets. With the increase of light burned magne-site in pellets, the RSI and RDI decrease gradually; when the proportion of light burned magnesite does not exceed 2.0% in pellets, the CS decreases slightly, but it still surnasses 2689 N. which can still meet the demand of BF.
基金Item Sponsored by National Natural Science Foundation of China (50474014)Provincial Key Technologies Research and Development Program of Liaoning of China(2008216005)
文摘According to the axisymmetric heat conduction of monolayer cylinder, a general method was deduced to calculate the axisymmetric temperature of linear heat conduction multilayer cylinder. Four types of boundary conditions were summarized and formulas for each type were derived. Then, a general calculating program was developed. Four temperature formulas could be expressed by a uniform equation, and the intermediate interface temperatures of axisymmetrical linear conduction multilayer cylinder satisfied tridiagonal linear and nonlinear systems of equations, which could be solved with the pursuit method and the Newton＇s method, respectively. With the calculating program, the temperature at any point of linear heat conduction multilayer cylinder could be obtained.
基金National Natural Science Foundation of China (50474014)
文摘The granule size distribution and the porosity of the granule packing process were researched. For realizing the optimizing control of the whole sintering production process, researchers must know the factors influencing the granule size distribution and the porosity. Therefore, tests were carried out in the laboratory with regard to the influences of the size and size distribution of raw materials and the total moisture content on the size and size distribution of granule. Moreover, tests for finding out the influences of the moisture content and the granule volume fraction on the porosity were also carried out. The results show that （1） the raw material has little influence on granulation when its size is in the range of 0. 51 mm to 1.0 mm; （2） the influence of the material size on granule size plays a dominant role, and in contrast, the moisture content creates a minor effect on granule size; （3） in binary packing system, with the increase in the constituent volume fraction, the porosity initially increases and then decreases, and there is a minimum value on the porosity curve of the binary mixture system; （4） the minimum value of the porosity in binary packing system occurs at different locations for different moisture contents, and this value shifts from right to left on the porosity curve with increasing the moisture content; （5） the addition of small granules to the same size component cannot create a significant influence on the porosity, whereas the addition of large granules to the same system can greatly change the porosity.
