8th International Symposium on High Temperature Metallurgical Processing: Poster Session I
Sponsored by: TMS Extraction and Processing Division, TMS: Pyrometallurgy Committee
Program Organizers: Jiann-Yang Hwang, Michigan Technological University; Tao Jiang, Central South University; Mark Kennedy, Proval Partners SA; Onuralp Yücel, ITU; P. Chris Pistorius, Carnegie Mellon University; Varadarajan Seshadri, Universidade Federal de Minas Gerais; Baojun Zhao, The University of Queensland; Dean Gregurek, RHI Magnesita; Ender Keskinkilic, Atilim University
Monday 6:00 PM
February 27, 2017
Room: Hall B1
Location: San Diego Convention Ctr
Session Chair: Weifeng Liu, Central South University
E-1: A Mini-pilot Plant for a Novel Flash Ironmaking Process: Amr Abdelghany1; Yousef Mohassab1; De Qiu Fan1; Mohamed Elzohiery1; H.Y. Sohn1; 1University of Utah
A novel flash ironmaking process is being developed at the University of Utah. A flash reactor with 0.8 m inner diameter, 1.5 m length, and three layers of refractory, insulation, and carbon steel forms the core of the facility. The reactor was designed to be capable of operating at temperatures up to 1600°C. The overall facility is described graphically from the burner, through which natural gas and oxygen are fed, and the solid feeding port to the flare stack, with the mini-pilot reactor as the centerpiece. The Human Machine Interface (HMI) and the control scheme used for the control and monitoring of the process are outlined. The safety precautions considered for different parts of the process and the emergency shutdown capability, provided to ensure the highest safety level in operating the mini-pilot plant, are presented. A CFD model for the flash reactor under development is also presented.
E-4: Effect of Lance Configurations on Coal Flow and Combustion Characteristics: Hailong Huo1; Zhenfeng Zhou1; Jingsong Wang1; Qingguo Xue1; Yuanyuan Zhang1; Yinli Liu1; 1University of Science and Technology Beijng
The coal burnout strongly depended on the residence time and dispersion of coal particles in the raceway region of a blast furnace. The residence time and dispersion of coal particles were directly related to the lance arrangement. In this work, a three dimensional model was developed to simulate the lance-blowpipe-tuyere-raceway region of a blast furnace. double lance and eccentric configurations were designed. For the double lance, the double-lance and eccentric double-lance were designed. Besides, for the eccentric double lance, the effect of intersection angle of the two lances was investigated.
E-5: Feasibility of Replacing the Internal Refractory (Iranian Production) and Implementation of Pilot in Almahdi Aluminium Line Production: Mohsen Amerisiahooei1; Borzu Baharvand2; 1Islamic Azad University; 2Almahdi-hormozal Aluminum Company
This study aimed to compare the internal refractory samples with companies to foreign samples to select the best type of Refractory to use for aluminum electrolysis cell in almahdi aluminium company has been done. At firest L-shaped and four samples of silica brick brick insulation were sampled and sent to the laboratory. They are based on chemical analysis, phase analysis, testing the strength and density were cold. The comparison between the properties of each of the samples was performed. Finally in this section, the decision was to choose the optimal refractory. The results show that the refractory used in the manufacture of flat external Gdaz•hay late and in some cases even better quality.
E-6: Inclusion Evolution during Ladle Furnace Refining and Deformation during Rolling Process for MRT-2.5: Yanan Jia1; Liguang Zhu2; Zengxun Liu2; Caijun Zhang2; Yan Wang3; 1University of Science and Technology Beijing; 2North China University of Science and Technology; 3North China Univercity of Science and Technology
Intensive steel samples were taken from industrial heats at various time during ladle furnace refining. The compositions, size distribution and morphology of inclusions in the samples were statistically analyzed by using a scanning electron microscope (SEM, ZEISS ULTRA55) and energy dispersive spectroscopy (EDS, OXFORD INSTRUMENTS INCA X-MAX50). The results showed that the inclusions were mainly MgO-CaO-Al2O3 containing little amounts of CaO. The average concentration of MgO in inclusions is about 10% although there is no Mg addition. The inclusion size tended to become larger with Ca concentration increasing in inclusions, and become smaller with Mg concentration increasing.The characteristic of inclusions during hot rolling was also investigated. In addition, the deforming mechanism of inclusions with different modification extents and sizes during hot rolling was proposed.
E-7: Kinetics and Reduction Behavior of Self-reducing Briquettes Containing Blast Furnace Dust: Shengli Wu1; Feng Chang1; Jianliang Zhang1; Hua Lu1; 1University of Science and Technology Beijing
Kinetic studies of the blast furnace dust (BFD) reduction process have been carried out under non-isothermal temperature condition. BFD pellets were made with bentonite as the binder. A Comprehensive Thermal Analyzer (TG-DSC) was used to determine the mass loss of pellets, which were heated at three heating rates of 10, 20, 30 K/min up to 1 493K. Furthermore, the metallization rate and mineral composition of BFD pellets heated to several different temperatures were analyzed by chemical analysis and X-ray diffraction (XRD). It was found that, with its inherent carbon resources as the reducing agent, the metallization rate of BFD pellets could reach 88% at most. The reduction and weight loss process of iron oxides mainly happens above 1273K. In addition, it was obtained from Coats-Redfern equation that the apparent activation energy of the reduction from wustite to Fe is 443kJ/mol and the mechanism function is interface reaction mechanism R2.
E-8: Melting Separation Slag and Metal Phases of High Grade of Vanadium-bearing Titanomagnetite Metallized Pellets: Chao Lv1; Kun Yang2; Shaojun Bai2; Shuming Wen2; 1 Kunming University of Science and Technology; 2Kunming University of Science and Technology
In this paper, in order to obtain high efficiency utilization of Panzhihua vanadium-bearing titanomagnetite concentrate, high grade of concentrate with FeT57.25% was enriched by fine grinding and twice of magnetic separation. Then the titanomagnetite pellets was reduced by graphite at 1250 C to reach high metallization degree above 80%. Melting and separation behavior of metallization pellets was performed to obtain metallic iron and titanium slag. The results showed that the effective separation of metal iron and slag could be obtained in which over 95% Fe was transferred into metal phase and over 93% Ti was enriched in slag in graphite crucible at 1500C and melting 60 min. the complete separation of slag and metal phases was achieved. The main components in the solid slag are geikielite(MgTi2O5), perovskite(CaTiO3), magnesia-alumina spinel and aluminum silicate, magnesium silicate. In the solidslag, the content of TiO2 reach to above 55%.
E-12: Study on Vanadium-titanium Gas-based Direct Reduction-grinding and Separation Process: Jingkun Tang1; 1Beijing Shenwu Environment & Energy Technology Co., Ltd.
A gas-based direct reduction technology was adopted for comprehensive utilization of Vanadium-Titanium from Mozambique, and the influence of processing parameters on the reduction effect, such as additive agent NCP dosage, reduction temperature, and reduction time, was studied. The results show that, after a reduction under the conditions such as the NCP dosage of 2%, the reduction temperature of 950℃ and the reduction time 240min, the metal ratio of oxide pellets reached 93.68%. Meanwhile, the influence of processing parameters on the grinding magnetic separation effect, such as grinding time, the intensity of magnetic separation, also was researched. Metal pellets which were grinded and beneficiated with a low intensity magnetic separator, and the TFe grade and recovery for the iron concentrate powder reached 79.25% and 91.12%, respectively, the V2O5 and TiO2 grade of slag reached 1.9% and 30.46%.
E-13: Effect of Silicon on Removal of Phosphorus from High Phosphorus Si-Mn Alloy by CaO-Based Slag: Zhiqiang Zhou1; Zizong Zhu1; Yuchuan Ding1; Shengnan Zhou1; 1ChongQing University
The effect of silicon on removal of phosphorus from high phosphorus Si-Mn alloy was investigated at 1673 K by CaO-based slag. It was found that the dephosphorization efficiency increases significantly as increasing the silicon content, which is due to the reaction between silicon and CaO at slag/alloy interface. The relation between silicon content with oxygen activity and phosphorus activity coefficient of Si-Mn melt was determined respectively as follows:lgaO=-1.55xSi-1.67 ; lnrP=9.26exSi/0.0433+11.0839 SiC was first discovered in the dephosphorization slag of high silicon Si-Mn alloy by XRD analyses. The carbon content in Si-Mn melt decreases continuously with the increasing silicon content, meanwhile, the decreasing rate of carbon content becomes rapid when the mole fraction of silicon is about 0.32. Such behaviors are beneficial for reducing dephosphorization process and low carbon Si-Mn alloy production.
E-16: Cleanliness Control Technology of Cold Rolled Steel Sheets: Haibo Li1; Peng Yuan1; Bin Chen1; Xinhua Wang2; Guosen Zhu3; 1Shougang Research Institute of Technology; 2University of Science and Technology Beijing; 3Shougang Jingtang Iron and Steel Co., Ltd.
The reoxidation of molten steel by oxidizing slag would affect molten steel cleanliness dirtectly during RH end to continuous casting. And there is a good relationship between molten steel cleanliness and the defects sources of cold rolled sheets. The surface defects of cold rolled sheets were analysed by SEM-EDS, then the positions and dimensions of inclusions in slab were calculated according to the width and depth of defects in sheet. The thermodynamic calculation results show the activity of iron oxide reduces with increasing of w(CaO)/w(Al2O3) appropriately when the content of T.Fe in slag remains lower level. In order to enhance the absorption ability of slag to Al2O3 inclusions, w(CaO)/w(Al2O3) should be controlled to 1.0~1.5 in liquid region of slag and w(CaO)/w(Al2O3) closely associate with the content of T.Fe in slag. By dynamic adjustment model of T.Fe content and w(CaO)/w(Al2O3) in slag, the defect ratio of sheets significantly declines.
E-18: Thermodynamics Study on Phosphorus Distribution between 2CaO•SiO2-3CaO•P2O5 Solid Solution and Liquid Slag: Chao Jiang1; Ming-Mei Zhu1; Rui-Rui Zhao1; Zhang-Guang Gao1; 1Chongqing University
This paper focuses on the CaO-SiO2-FeO-MgO-MnO-P2O5 slag system that represents the major components of dephosphorization slag in BOF. Phosphorus distribution between 2CaO•SiO2-3CaO•P2O5 Solid Solution and Liquid Slag were analyzed by FactSage. And then discussed the effects of slag content（basicity, FeO, P2O5） on the distribution ratio of P between the solid solution phase and the liquid phase (Lp) and the percentage content of P in solid solution phase and liquid phase. The results show that, with the increase of basicity, Lp (wt.%) decreases until the basicity reaches 1.9, then it turns to increase. In contrast, Lp (mass) shows no significant variation. Lp (wt.%) increases gradually with the increasing amount of FeO or P2O5. By contrast, Lp (mass) goes up with the increase of P2O5 while drops with increasing FeO content.
E-19: Effect of Super Gravity on the Solidification Structure and C Segregation of High Carbon Steel: Yuhou Yang1; Bo Song1; Gaoyang Song1; Zeyun Cai1; 1University of Science and Technology Beijing
Super gravity was introduced in the solidification process of high carbon steel. The experiment results show that the solidification structure can be refined by applying super gravity at the cooling rate of 10 °C/min. Obviously, both the primary and secondary dendrite length was greatly reduced. In addition, the eutectic structure in the interdendritic tends to be spheroidized and refined. However, the macro-segregation of C along the direction of super gravity was caused with higher wt percent at the upper area than that at the bottom of the sample. The mechanism of solidification structure refinement and the C macro-segregation in super gravity field were also discussed in this paper.
E-20: Burden Composition and Structure Optimization in Blast Furnace Operation Based on Multi-objective Programming: Baoxiang Wang1; 1North China University of Science and Technology
It is very hard to select reasonable burden composition and structure in blast furnace operation because of too many operation factors. In order to minimize pig iron cost, ensure the quantity and quality, in this paper, a multi-objective programming model was realized to optimize the burden composition and structure. Based on the iron-making theory, the optimization project selected the lowest per ton iron cost and the minimum per ton slag amount as objective function and 12 parameters as constraints, and used the multi-objective programming method to build the whole model. As the result, it could be obtained the optimum burden composition and structure satisfied with all constraint conditions. Compared with the traditional production testing and hand calculation in blast furnace operation, the project greatly reduced the production risk and greatly increased the calculation accuracy. The industrial application shows this project is especially beneficial to reduce the pig iron cost.
E-17: Behaviour of Silicon in Nickel Laterite by Carbothermic Reduction in Vacuum: Lei Shi1; Tao Qu1; Dachun Liu1; Yang Tian1; Bin Yang1; Yongnian Dai1; Jian Wu1; 1Kunming University of Science and Technology
The carbon thermal reduction of high Mg-Si nickel laterite was studied under vacuum. The effects of adding calcium oxide and the reducing agent on the reduction of silicon in residue were studied. At system pressures of 10~200 Pa and different temperatures, the proportions of carbon and CaO were varied. The analysis of the residue was performed using X-ray diffraction and chemical composition analysis. The results show the following: at 1350 ℃ with a C/O ratio of 1.5:1, the recovery of Si reached a maximum 71.09%. Under these conditions, Si exists mainly in the forms of Fe3Si, Fe2Si, FeSi and SiC. The recovery of Si was above 80% when the temperature was 1450 ℃, the C/O ratio was 1:1, and the addition of CaO was more than 15%. When CaO was 22.61%, all of the solid phase was Ca2SiO4.
E-26: Effect of CaO Addition on the Behavior of Vanadium and Phosphorus during Oxidation and Leaching Process: Zhang Tao1; Zhou Wang2; Li Dong-Wei1; Diao Jiang2; 1Chongqing University of Education; 2Chongqing University
The feasibility of simultaneous vanadium extraction and phosphorus removal from vanadium-containing hot metal was demonstrated with laboratory experimental investigation. The effect of CaO addition on the distribution behavior of vanadium, phosphorus between basic vanadium slag and semi-steel as well as the influence of basicity on the leaching behavior of vanadium, phosphorus were particularly studied. Results show that vanadium oxidation ratio slightly decreasing with the increase of basicity, but phosphorus oxidation ratio rapidly increasing with the increase of basicity. The leaching of roasted vanadium slag with various CaO contents indicated that the optimal slag basicity for extracting vanadium was 1.5. The maximum leaching efficiency of vanadium could reach 84.02% and the sequence of vanadium leaching efficiency by using different leaching reagents was: 160g/L Na2CO3 > 100g/L NaHCO3 > 400g/L (NH4)2CO3 > 5% H2SO4.