Robust optimization and stochastic programming approaches for medium-term production scheduling of a large-scale steelmaking continuous casting process under demand uncertainty

Scheduling of steelmaking-continuous casting (SCC) processes is of major importance in iron and steel operations since it is often a bottleneck in iron and steel production. In practice, uncertainties are unavoidable and include demand fluctuations, processing time uncertainty, and equipment malfunction. In the presence of these uncertainties, an optimal schedule generated using nominal parameter values may often be suboptimal or even become infeasible. In this paper, we introduce robust optimization and stochastic programming approaches for addressing demand uncertainty in steelmaking continuous casting operations. In the robust optimization framework, a deterministic robust counterpart optimization model is introduced to guarantee that the production schedule remains feasible for the varying demands. Also, a two-stage scenario based stochastic programming framework is investigated for the scheduling of steelmaking and continuous operations under demand uncertainty. To make the resulting stochastic programming problem computationally tractable, a scenario reduction method has been applied to reduce the number of scenarios to a small set of representative realizations. Results from both the robust optimization and stochastic programming methods demonstrate robustness under demand uncertainty and that the robust optimization-based solution is of comparable quality to the two-stage stochastic programming based solution.     

A techno-economic evaluation of the use of hydrogen in a steel production process,utilizing nuclear process heat

Due to the growing environmental concern about global warming, there is immense pressure on the metallurgical industry to lower their carbon dioxide emissions. This article evaluates the use of hydrogen, produced by a Hybrid Sulphur process which utilizes nuclear process heat, as a reducing agent in the steel industry. Two commercial steelmaking processes and an alternative one were investigated to resolve what influence nuclear hydrogen would have on the carbon dioxide emissions and the production cost of these processes. Overall it was found the steel industry could benefit a great deal from utilizing nuclear hydrogen.     

宝钢技术部检测中心60R系统施工体会

简要介绍冶金工厂气动送样装置基本状况以及安装的施工方法和注意事项。     

宝钢FGD工艺抉择之我见

论述了国外ＦＧＤ（烟气脱硫）的发展和国内的进展以及ＦＧＤ工艺选择原则。较详细地介绍了湿式氨法、干式氨法以及钢渣法的ＦＧＤ流程。同时就宝钢实施ＦＧＤ的可能性作了分析。     

Fixation of CO2 by carbonating calcium derived from blast furnace slag

Industrial waste materials, such as steelmaking slags, appear to be potential raw materials for reducing CO₂ emissions by carbonation. The suitability of applying a carbonation route based on acetic acid leaching to produce carbonates from blast furnace slag is presented in this study. The effect of solution pH, temperature, and CO₂ pressure on the precipitation of carbonates was experimentally studied. A simple thermodynamic model was used to verify our results. The feasibility of the process was also discussed, addressing energy input requirements and the consumption of chemicals.     

废钢中有害元素的去除技术

分析了废钢资源及废钢质量的状况，提出了改善废钢质量途径，介绍了国内外去除废钢中有害元素的研究现状。     

连铸结晶器电磁制动对铸坯中非金属夹杂物影响的研究

对梅钢2^#连铸机采用的FC-Mold（Flow Control Mold）全幅二段电磁制动器对钢中非金属夹杂物的影响进行了研究。结果表明,采用电磁制动后,铸坯中心的夹杂物总个数少于未采用电磁制动的铸坯,而前者边部的夹杂物个数则是后者的2.06倍;铸坯中心和边部的夹杂物平均直径和平均面积均有所减小,铸坯中心的平均面积减小量达到8.44μm^2。钢中的夹杂物主要为直径全部小于20μm的Al2O3、MnS和CaS夹杂物,还有少量含K、Na的夹杂物。未采用电磁制动的铸坯中含K、Na夹杂物的数量明显多于采用电磁制动的铸坯。采用电磁制动明显降低结晶器液面的波动幅度,这有助于减少卷渣几率。电磁制动使用技术还有待于进一步优化研究。     

抚顺特钢电弧炉USTB炉壁氧气喷吹工艺的应用

抚顺特钢与北京科技大学合作在第一炼钢厂1座50t EBT电弧炉和1座60t竖式电弧炉上采用USIB(北京科技大学)炉壁氧气喷吹工艺。使用结果表明，全废钢炉料冶炼周期缩短4．9～7．2min，废钢 30％铁水冶炼周期缩短9．4～10．9min，电耗降低17．9～37．2kWh／t，氧耗增加～4．5m^3/t。USIB氧枪的使用寿命达1000炉以上，取得了良好的经济技术效果。     

转炉冶炼超低碳、超低氮钢的工艺技术

分析了武钢90t顶底复吹转炉冶炼<0.005%C,≤0.005%N超低碳、氮钢的两种冶炼工艺技术,即常规工艺:KR脱S→LD→RHKTB→CC和双联工艺:KR脱S→LD脱Si、P→LD复吹脱碳→RHKTB→CC。实践表明,常规工艺冶炼时中间包钢水平均C含量为25.5×10-6、平均N含量为18.5×10-6;双联工艺冶炼时,中间包钢水平均C含量为16×10-6、平均N含量为19×10-6,双联工艺吹炼终点[P](60×10-6)比常规工艺(110×10-6)低。     

不锈钢电弧炉粉尘直接还原回收工艺研究

电弧炉粉尘巳被列为有害废物，直接还原回收粉尘中有价金属不仅可保护环境，而且可充分利用宝贵的金属资源。采用中频感应电炉模拟电弧炉冶炼工艺进行了A、B、C和D系列实验研究。通过气体成分的检测、钢锭和炉渣的成分分析，了解工艺参数对还原过程的影响，认为电弧炉粉尘直接还原回收工艺切实可行，不影响钢产品质量，为该新工艺的生产实践提供了依据。