Control Model of Multifunctional Hot Metal Ladles

For further research on the control model of muhifunctional hot metal ladles between the ironmaking and steelmaking interface, the hot metal ladies of K steel plant were taken as the object to analyze the operation process. The factors of blast furnace supply and basic oxygen furnace demand were proposed. According to the principle of supply and demand balance, the control model of hot metal was researched under the following factor conditions： equal to, greater than, and less than 1, respectively. The distribution model of the blast furnace, sleelmaking works, and online buffering was proposed. When the supply and demand factor is equal to ） , the turnover number of hot metal ladles equals 16 and the turnover cycle of hot metal ladles equals 512 min. When the factor is greater than 1, the total number of hot metal ladles is equal to the normal turnover number plus the turnover number of the cast iron machine. When the factor is less than 1, the total number of hot metal ladles is equal tO the normal turnover number plus the accumulating number. Satisfactory effects were obtained by applying the control model in produc tion. The numbers of turnover ladles and accumulating ladles were reduced.

Physicochemical properties of coconut husk activated carbon modified by Fe(N0_(3))_(3)and Mn(N0_(3))_(2)

Fe-loaded activated carbon(AC)has high surface acidity and more active sites,while manganese-loaded AC has high oxygen content.Coconut husk AC modified by Fe-Mn was studied with the aim of revealing the modification mechanism.First,HNO_(3)AC was prepared using the nitric acid immersion method.Second,Fe-Mn/AC was prepared using the Fe(N0_(3))_(3)and Mn(N0_(3))_(2)sequential immersion.The effects of HNO_(3),Fe(N0_(3))_(3),and Mn(N0_(3))_(2)on the pore texture and surface chemical characteristics of carbon materials were examined by scanning electron microscopy,Brunauer-Emmett-Teller(BET)analysis,X-ray diffraction and Fourier-transform infrared spectroscopy.The surface topography,pore structure,active material,and functional groups of AC,HNO_(3)/AC,and Fe-Mn/AC were systematically studied.The following results were obtained.The surface of HNO_(3)AC has more ditches and air voids;the micropores of HNO_(3)AC are deformed and flattened compared to those of AC.The surface of Fe-Mn/AC exhibits an accumulation phenomenon.MnFe_(2)O_(4)and FeMn_(2)O_(4)formed more pore structures.AC and HNO_(3)AC have numerous micropores.The higher loading quantity of Fe-Mn results in bigger specific surface.The active components of Fe-Mn/AC-1,Fe-Mn/AC-2,Fe-Mn/AC-3,and Fe-Mn/AC-4 are MnFe_(2)O_(4),MnO_(0.43)Fe_(2.57)O_(4),Mn_(3)O_(4),and ot-Fe_(2)O_(3)>respectively.The surface functional groups of AC and HNO_(3)AC are oxygen-containing functional groups.The effect of Fe-Mn modifying conditions on functional group species is rare;however,Fe/AC has more oxygen-containing functional groups.These research findings can aid in the desulfurization and denitrification of the Fe-Mn/AC catalyst.

Steel ladle exchange models during steelmaking and continuous casting process

The models and influencing factors of steel ladles exchange during the steelmaking and continuous casting process of H steel plant were investigated. Based on analysis of the operation process and turnover time of steel ladles, relationship models for the turnover number, turnover rate, continuous casting number, number of ladles with additional turnover, and number of ladles without additional turnover were built. The turnover rules of steel ladles for one basic oxygen furnace （BOF） matching one continuous caster （CC） and two BOFs matching two CCs modes were simulated by using a Gantt chart. The models of steel ladle exchange were proposed for casting of a single CC and overlapping casting of two CCs. By analyzing the influencing factors, the following conclusions were drawn. The exchange ladle should not have the task of transporting liquid ste^l in the CC that stops casting earli- er. The end time of the empty ladle in the CC that stops casting earlier should be earlier than the start time of the full ladle in the CC that stops casting later. After evaluating the factors influencing the start casting time, turnover cycle, casting time, continuous casting number, and overlapping time, a prioritization scheme of steel ladle exchange was proposed based on the steel grade. First, the turn- over cycle and single heat casting time were determined; based on these, a reasonable ladle turnover number was calculated. Second, the turnover number and continuous casting number were optimized for maximizing the number of ladles without additional turnover. Lastly, to reduce the casting number during the overlapping time to be lower than the turnover number, the overlapping time was shortened.