New age,new steel

Baosteel,which has just recovered from the global economic downturn,is deeply aware of the need for reforms,even revolutions,in the development of the steel industry."Green" steel is an ultimate goal for Baosteel to fulfill its social responsibilities.Learning from its long-term business operation and market competition,Baosteel has chosen technological innovation and built a low-carbon road to achieve "green" steel.It has also raised three tasks of "environmental operation" and endeavors to incorporate "environmental operation" into normal business operation,reestablishing its value system based on costs and lifecycles,reducing pressure on the environment and building a brand new role for iron and steel.     

Hazard Control of NOxin Hot Stove

Hazard control of NOxis very important for the long life of hot stove shell and environmental protection.NOxconcentrations during different operation periods of hot stove were calculated according to thermodynamical and dynamical analyses.The results were verified by the previously measured data.Then,the influence of hot stove operation parameters on NOxconcentration and the mechanism of liquid water formation in hot stove were studied.The results indicated that in gas period,the dome temperature should be controlled below 1 420 ℃in order to decrease NOxemission.In the case of banking operation,NOxconcentration was about 40-60times higher than that in gas period.Hence,reasonable measures should be taken to reduce banking operation,especially in the situation of large excess air ratio.Since NOxformed during the whole operation process,the most effective way of preventing liquid water and HNO3generation is to control the pipe and shell temperature,which should be higher than the condensation temperature of water vapour.The condensation temperature should be considered as the design temperature of pipe and shell for hot stove.     

Characteristics of Large Inclusions in High Grade Pipeline Steel

Good internal quality of steel pipes is a basic guarantee for the safe and efficient operation of pipeline system.While presence of large inclusions has adverse effect on the mechanical properties,weldability and corrosion resistance of the steel pipes,and then it would bring huge risk to the safe operation of oil and gas transmission pipeline.In order to reduce the risk to a minimum extent,it is quite necessary to analysis and study the characteristics of large inclusions in high grade pipeline steel,and then it would provide evidence for the formulation of level-determination standard of large inclusions during steel pipe acceptance.Optimized production technology such as electromagnetic stirring is put forward accordingly to prevent the occurrence of large inclusions in pipeline steel.     

Development of laser and microwave scanning technologies in the blast furnace burden profile and lining condition measurement at CSC

In order to stabilise the operation of the blast furnace and to raise its operation efficiency,research works for the application of microwave and laser scanning technologies to the measurement have been intensively carried out at China Steel Corporation(CSC).To monitor the burden profile during the operation,a microwave burden profile measuring system was developed.The system consists of a radar unit,a signal processing system, and a driving device which is capable of rotating the radar to scan the burd...     

Numerical Analysis of Blast Furnace Performance Under Charging Iron-Bearing Burdens With High Reducibility

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 high-reducibility sinter and carbon composite agglomerates for practical application at a blast furnace.     

Numerical Analysis of Blast Furnace Performance Under Charging IronBearing Burdens With High Reducibility

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 highreducibility sinter and carbon composite agglomerates for practical application at a blast furnace.     

Monitoring Method for Blast Furnace Wall With Copper Staves

 A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of “inverse problem” and the concept “non inverse problem”, the monitoring program for blast furnace wall with copper staves has been realized, which can be used to calculate online the accretion thickness and temperature of hot surface of copper staves after obtaining the values of thermocouples of copper staves. The accretion state obtained in the actual investigation has proved that the result of the program is correct. The monitoring program shows that the accretion would easily fluctuate when the accretion layer is extremely thick or thin, thereby the stable and smooth operation of the blast furnace is hindered. By maintaining appropriate accretion thickness, both long campaigns and high productivity of the blast furnace can be achieved; furthermore, it can also optimize the operation of blast furnace and maximize its production. Approximately 30-50 mm in thickness of accretion layer is maintained on the wall of Shougang blast furnace 2, which can meet the requirement for obtaining both long campaign and high productivity.     

高压配电设备及运行条件探讨

High voltage power distribution equipment is in the power system of high pressure distribution cabinets,generator,transformer,electric power lines,circuit breakers,low-voltage switchgear,panel,switch box,control box,etc equipment collectively.High voltage power distribution equipment is the premise of high-voltage lines normal operation conditions,and its operation conditions and high pressure equipment to ensure sufficient conditions of operation.So for power distribution equipment and operating conditions of the discussions is particularly important.Keywords:high voltage power distribution equipment,run,conditions.     

Study of Magnetically Impelled Arc Butt Welder for Tube to Sheet Welding

Magnetically impelled arc butt welder is mainly used in the automotive industry for butt welding tubes.To extend the range of the welding applications,a new type of magnetically impelled arc butt welder for tube to plate welding had been developed.The welder consisted two parts of mechanical device and electrical control system,in which the mechanical device with an appropriate clamping,location and upsetting control was specially designed for simple operation.The electrical control system involved the power supply,magnetic field and logic control of the welding.So the starting and rotating behaviour of the arc in the welding region of tube and sheet can be accurately controlled for the quality of tube to sheet joints.As a result,the welder for tube to sheet welding could generate a stable rotating arc by adjusting the welding parameters,and had a constant high-quality joint.     

Hybrid Neural Network Model for RH Vacuum Refining Process Control

A hybrid neural network model, in which RH process (theoretical) model is combined organically with neural network (NN) and case-base reasoning (CBR), was established.The CBR method was used to select the operation mode and the RH operational guide parameters for different steel grades according to the initial conditions of molten steel, and a three-layer BP neural network was adopted to deal with nonlinear factors for improving and compensating the limitations of technological model for RH process control and end-point prediction. It was verified that the hybrid neural network is effective for improving the precision and calculation efficiency of the model.     

Multi-Period Optimal Distribution Model of Energy Medium and Its Application

 A mathematical model of optimal energy medium distribution in steelmaking process is formulated. In this model, three kinds of important energy mediums including byproduct gases, steam and electricity are considered, and the objective function accounts for both the change of generation and consumption of the byproduct gases and the demand of low (or middle) pressure steam and electricity for each period to maximize the benefit of products cost and minimize the consumption of energy. The results indicate that the optimal distribution scheme of byproduct gases, middle pressure steam, low pressure steam and electricity is achieved and case study shows that 6% of operation cost is reduced by using the proposed model comparing with the previous model.     

Speed Control and Coiling Temperature Control of Strip

Considering the strip speed during controlled laminar cooling on Baosteel 1580 hot strip mill in China, the influence of strip speed fluctuation on coiling temperature control for the tail and “neck” of the strip was analyzed. The optimization strategies were put forward and proved effective in operation.     

A brief consideration about PCI of COREX melter-gasifier

By analyzing the thermal and burden structure conditions inside the melter-gasifier of COREX process,the advantage and disadvantage of PCI into the melter-gasifier are clarified.The influence of PCI on the running condition inside the furnace is analyzed based on the information from production operation and mathematical and physical simulations,and measures to tackle with the problems arising from PCI are proposed.The main results are as follows.①Due to the unfavorable conditions for coking of coal in t...     

Henan Non-ferrous Holding Company Set Up in Henan

Henan Non-ferrous Holding Co.(hereinafter referred to as Henan Non-ferrous),an enterprise set up under the joint effort of 3 enterprises with state-owned assets namely Shenhuo Group,Yichuan Power and Yulian Group,has started its operation under tight schedule.The focus of the current operation is acquisition,for which a number of alumina and aluminum processing enterprises are on the list of Henan Non-ferrous.China Nonferrous Metals Monthly reported this news at our last issue,now we try to analysis more details behind the decision.     

Jiuhua Smelter of Anhui Tongguan Non-Ferrous Metal Co., Ltd (Chizhou) Was Put Into Operation for Trial

On the morning of 28 August,Jiuhua Smelter of Anhui Tongguan Non-Ferrous Metal Co., Ltd(Chizhou)was put into operation for trial, which marked the Chizhou Non-Ferrous and Weike,which were closed down for one year, came back to life after being reorganized for the second time.It was said that with the support of the provincial government,Tongling     

Effect of limestone injection into furnace and desulfurization on boiler’s operation characteristics

In combination with the related documents and actual experience in the project operation,this paper analyzes the effect of limestone injection into furnace and desulfurization (LIFDS) on furnace slagging tendency,dust deposit speed of the heating surface,wearing,corrosion,boiler’s combustion conditions and combustion efficiency,secondary pollution,etc.Based on this situation,some countermeasures and suggestions were advanced so as to strengthen the boiler’s soot-blowing management,the operation of ash removal,supervision,and analysis of boiler operation parameters,planned inspection during the maintenance downtime,tracking management of coal quality and optimization of the operation and management.All these have a directive meaning to boilers’ safety operation.     

Optimization of Cooling Process of Iron Ore Pellets Based on Mathematical Model and Data Mining

Cooling process of iron ore pellets in a circular cooler has great impacts on the pellet quality and systematic energy exploitation. However, multi-variables and non-visualization of this gray system is unfavorable to efficient production. Thus, the cooling process of iron ore pellets was optimized using mathematical model and data mining techniques. A mathematical model was established and validated by steady-state production data, and the results show that the calculated values coincide very well with the measured values. Based on the proposed model, effects of important process parameters on gas-pellet temperature profiles within the circular cooler were analyzed to better understand the entire cooling process. Two data mining techniques—Association Rules Induction and Clustering were also applied on the steady-state production data to obtain expertise operating rules and optimized targets. Finally, an optimized control strategy for the circular cooler was proposed and an operation guidance system was developed. The system could realize the visualization of thermal process at steady state and provide operation guidance to optimize the circular cooler.     

Mathematical simulation of burden distribution in COREX 3000 shaft by discrete element method

The distribution of reducing gas in a shaft furnace dominates the temperature profile,gas utilization ratio,metallization degree and is the overwhelming factor for stable,high productivities and low-energy-consumption operation.At the same time,the distribution of gas flow is mainly determined by the position of gas inlet,the packed bed porosity distribution as well as its change due to the difference on the mode of top charge and bottom discharge.When injecting position of the process is fixed,the charg...     

Study of measurement and control of free loop of hot steel strip in twin-roll strip casting

In the twin-roll strip casting process,hot cast strips can be broken or torn if the casting speed does not match the rolling speed.Usually,a certain length of hot steel strip is hung freely between the caster and rolling mill to deal with the effect of this speed difference.In this paper,the freely hanging hot steel strip is referred to as the free loop of hot steel strip.Accurately measuring and controlling the height of this free loop is the key factor in maintaining a stable casting operation.Several methods for measuring the loop height of a steel strip are discussed and a method for accurately measuring and controlling the free loop height of hot steel strip is presented.Based on the results of the casting loop quantity change curve,this control method is confirmed to be effective and able to meet the requirements of continuous casting strip production.     

Bridging complexes of rare earth and cobalt cluster as catalyst precursors for Fischer-Tropsch synthesis

Three new bridging complexes of rare earth and cobalt cluster were synthesized and characterized via ICP, IR and TG techniques. The structure of the complexes was speculated as: two rare earth atoms were bridged with four CF3COO-, and rare earth atoms were coordinated with cobalt carbonyl clusters to form a steady structure. Application of the complexes as the catalyst precursors was explored for Fischer-Tropsch synthesis. The study showed that the bridging complexes of rare earth and cobalt cluster had large molecular size and were difficult to enter pore path of γ-Al2O3, so they were dispersed on the surface of γ-Al2O3 support. In addition, the performance of Co(Ce)/ γ-Al2O3 was the best among the catalysts with complex as precursor and maintained 77.7% CO conversion at 220 oC for 80 operation hours.