The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author wi...The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was used to investigate the fluid flow and mixing characteristics in the bath of an 18 t AOD vessel, as well as the 'back attack' action of gas jets and its effects on the erosion and wear of the refractory lining, with sufficiently full kinematic similarity. The non rotating and rotating gas jets blown through two annular tuyeres, respectively of straight tube and spiral flat tube type, were employed in the experiments. The geometric similarity ratio between the model and its prototype (including the straight tube type tuyeres) was 1:3. The influences of the gas flow rate, the angle included between the two tuyeres and other operating parameters, and the suitability of the spiral tuyere as a practical application, were examined. These latest studies have clearly and successfully brought to light the fluid flow and mixing characteristics in the bath and the overall features of the back attack phenomena of gas jets during the blowing, and have offered a better understanding of the refining process. Besides, mathematical modeling for the refining process of stainless steel was carried out and a new mathematical model of the process was proposed and developed. The model performs the rate calculations of the refining and the mass and heat balances of the system. Also, the effects of the operating factors, including adding the slag materials, crop ends, and scrap, and alloy agents; the non isothermal conditions; the changes in the amounts of metal and slag during the refining; and other factors were all considered. The model was used to deal with and analyze the austenitic stainless steel making (including ultra low carbon steel) and was tested on data of 32 heats obtained in producing 304 grade steel in an 18 t AOD vessel. The changes in the bath composition and temperature during the refining process with time can be accurately predicted using this model. The model can provide some very useful information and a reliable basis for optimizing the process practice of the refining of stainless steel and control of the process in real time and online.展开更多
The stirring of a molten steel ladle with argon injection through a top submerged lance and a bottom nozzle is numerically studied here through Computational Fluid Dynamics (CFD) simulations. Three lance submergence d...The stirring of a molten steel ladle with argon injection through a top submerged lance and a bottom nozzle is numerically studied here through Computational Fluid Dynamics (CFD) simulations. Three lance submergence depths and three injection velocities are considered in the CFD numerical experiments. The turbulent dissipation rate is employed to characterize the stirring phenomenon. The mixing times are determined from the gas flow rate, ladle geometry and bath depth using an empirical correlation.展开更多
黄泥湖铀矿床是赣南典型的热液铀矿床，文章通过对该矿床成矿期形成的萤石、方解石和黄铁矿中流体包裹体的 He 、 Ar 同位素的测定表明，黄泥湖铀矿床流体包裹体中3 He/4 He 值为0.007～2.272 Ra （绝大部分在0.024～1.754 Ra），40 Ar/...黄泥湖铀矿床是赣南典型的热液铀矿床，文章通过对该矿床成矿期形成的萤石、方解石和黄铁矿中流体包裹体的 He 、 Ar 同位素的测定表明，黄泥湖铀矿床流体包裹体中3 He/4 He 值为0.007～2.272 Ra （绝大部分在0.024～1.754 Ra），40 Ar/36 Ar 值为191.6～1126.1（绝大部分高于295.5），认为成矿流体的氦具有壳幔混合来源特征，其中幔源流体占主导地位，地壳流体端元为含有一定放射性成因 Ar 的大气降水。结合前人研究成果，认为黄泥湖铀矿床为深源热液成因，与晚燕山期华南岩石圈伸展作用有关。展开更多
In the Yutianbao Mine, the Nantong Coal Field, Chongqing, a lot of gas samples were measured and analyzed. It has been found in these samples that helium is sensitive to stress concentration, while argon is sensitive ...In the Yutianbao Mine, the Nantong Coal Field, Chongqing, a lot of gas samples were measured and analyzed. It has been found in these samples that helium is sensitive to stress concentration, while argon is sensitive to stress release. Compared with the flowing out of gas it-self, the combination of helium and argon can be more suitably used as an indicator to predict gas outburst. In a mining area of this mine, both δ He > 30 and δ Ar < ?0.97 can be used critically to define the dangerous area. Also, the contour maps of δ He, δ Ar and CH4 can provide a guidance for engineering monitoring.展开更多
Chemical and isotopic compositions of He, Ar, CH4(δ13C) of hot spring gas in Lancang and Batang earthquake regions show that the concentrations of He , H2 , non-atmospheric sourced N2 and 3He/4He value are closely re...Chemical and isotopic compositions of He, Ar, CH4(δ13C) of hot spring gas in Lancang and Batang earthquake regions show that the concentrations of He , H2 , non-atmospheric sourced N2 and 3He/4He value are closely related to seismic activity. During earthquake activity, gas release is related to the dilation that rocks take on under stress action. Earthquake magnitude (energy) between the two seismic regions suggests that the amount of released gas from rocks increases significantly with the increase of magnitude and energy. As indicators of earthquake prediction, the following parameters of gases from hot spring are effective: He, 3He/4He, H2 and N2B/N2total.展开更多
文摘The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was used to investigate the fluid flow and mixing characteristics in the bath of an 18 t AOD vessel, as well as the 'back attack' action of gas jets and its effects on the erosion and wear of the refractory lining, with sufficiently full kinematic similarity. The non rotating and rotating gas jets blown through two annular tuyeres, respectively of straight tube and spiral flat tube type, were employed in the experiments. The geometric similarity ratio between the model and its prototype (including the straight tube type tuyeres) was 1:3. The influences of the gas flow rate, the angle included between the two tuyeres and other operating parameters, and the suitability of the spiral tuyere as a practical application, were examined. These latest studies have clearly and successfully brought to light the fluid flow and mixing characteristics in the bath and the overall features of the back attack phenomena of gas jets during the blowing, and have offered a better understanding of the refining process. Besides, mathematical modeling for the refining process of stainless steel was carried out and a new mathematical model of the process was proposed and developed. The model performs the rate calculations of the refining and the mass and heat balances of the system. Also, the effects of the operating factors, including adding the slag materials, crop ends, and scrap, and alloy agents; the non isothermal conditions; the changes in the amounts of metal and slag during the refining; and other factors were all considered. The model was used to deal with and analyze the austenitic stainless steel making (including ultra low carbon steel) and was tested on data of 32 heats obtained in producing 304 grade steel in an 18 t AOD vessel. The changes in the bath composition and temperature during the refining process with time can be accurately predicted using this model. The model can provide some very useful information and a reliable basis for optimizing the process practice of the refining of stainless steel and control of the process in real time and online.
文摘The stirring of a molten steel ladle with argon injection through a top submerged lance and a bottom nozzle is numerically studied here through Computational Fluid Dynamics (CFD) simulations. Three lance submergence depths and three injection velocities are considered in the CFD numerical experiments. The turbulent dissipation rate is employed to characterize the stirring phenomenon. The mixing times are determined from the gas flow rate, ladle geometry and bath depth using an empirical correlation.
文摘黄泥湖铀矿床是赣南典型的热液铀矿床，文章通过对该矿床成矿期形成的萤石、方解石和黄铁矿中流体包裹体的 He 、 Ar 同位素的测定表明，黄泥湖铀矿床流体包裹体中3 He/4 He 值为0.007～2.272 Ra （绝大部分在0.024～1.754 Ra），40 Ar/36 Ar 值为191.6～1126.1（绝大部分高于295.5），认为成矿流体的氦具有壳幔混合来源特征，其中幔源流体占主导地位，地壳流体端元为含有一定放射性成因 Ar 的大气降水。结合前人研究成果，认为黄泥湖铀矿床为深源热液成因，与晚燕山期华南岩石圈伸展作用有关。
基金Most of this study was finished during the Fifth Five-Year-Plan period and financially supported by the National Natural Science Foundation of China (Grant No. 49672163). References
文摘In the Yutianbao Mine, the Nantong Coal Field, Chongqing, a lot of gas samples were measured and analyzed. It has been found in these samples that helium is sensitive to stress concentration, while argon is sensitive to stress release. Compared with the flowing out of gas it-self, the combination of helium and argon can be more suitably used as an indicator to predict gas outburst. In a mining area of this mine, both δ He > 30 and δ Ar < ?0.97 can be used critically to define the dangerous area. Also, the contour maps of δ He, δ Ar and CH4 can provide a guidance for engineering monitoring.
基金Project supported by the National Natural Science Foundation of China.
文摘Chemical and isotopic compositions of He, Ar, CH4(δ13C) of hot spring gas in Lancang and Batang earthquake regions show that the concentrations of He , H2 , non-atmospheric sourced N2 and 3He/4He value are closely related to seismic activity. During earthquake activity, gas release is related to the dilation that rocks take on under stress action. Earthquake magnitude (energy) between the two seismic regions suggests that the amount of released gas from rocks increases significantly with the increase of magnitude and energy. As indicators of earthquake prediction, the following parameters of gases from hot spring are effective: He, 3He/4He, H2 and N2B/N2total.
