8th International Symposium on High Temperature Metallurgical Processing: Poster Session II
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: Yuanbo Zhang, Central South University
E-27: Investigation on the Phase Transformation of Vanadium Slag during the Direct Reduction Process: Wen-Feng Tan1; Bing Xie1; Pan Gu1; Hong-Yi Li1; Jiang Diao1; Wang Zhou1; 1Chongqing University
In order to remove silicon dioxide and improve the grade of vanadium slag, a novel direct reduction pretreatment process is proposed. The phases transformation of vanadium slag is investigated by X-ray diffraction analysis. The results indicate that the reduction temperature make great influence on the phases composition of vanadium slag. The phases consist of spinels, augites, olivine and carbon in vanadium slag at the reduction temperature of 1023 K. While the reduction temperature increased to 1073 K, two new phases of metallic iron and silica appear. With the further increase of reduction temperature to 1173 K, goldmanite generate. As increasing the reduction temperature to 1223 K, vanadium oxide (VO) could form, meanwhile, olivine disappears. The optimum conditions for reduction are that keep temperature at 1223K and the duration for 3 hours, while ensure the ratio of carbon and vanadium slag at 1:5.
E-28: Effect of Al2O3 Content on the Crystallization Behavior of Blast Furnace Slag Using Single Hot Thermocouple Technique: Qin Yuelin1; Yang Yanhua1; Zhang Qianying1; Deng Nengyun1; 1Chongqing University Of Science and Technology
The critical cooling rate required for the formation of glassy slag is one of the important characteristics for molten BF slag. The crystallization behavior of molten BF slag has been studied by in situ observation with the single hot thermocouple technique. The isothermal and non-isothermal experiments were performed to construct time-temperature-transformation and continuous-cooling-transformation diagrams. The effect of Al2O3 on the critical cooling rate of the CaO-SiO2-MgO-Al2O3 slags were studied under conditions of CaO/SiO2 = 1.2, 8 mass% MgO and 10~16 mass% Al2O3. The following finding are reported in the present paper: (i) Higher Al2O3 content decreased the critical cooling rate. (ii) The crystallization temperature of molten BF slag lowers as the cooling rate increases, the slag have larger critical cooling rate, higher crystallization temperature. The results could be used to design proper cooling path of molten BF slag for the formation of glassy.
E-29: Investigation of the Carbothermic Reduction of Chromium-containing Vanadium Extraction Residue: Pan Gu1; Jiang Diao1; Wen-Feng Tan1; Bing Xie1; Wang Zhou1; Zhen Zhang1; 1Chongqing University
In order to utilize the chromium resource in chromium containing vanadium extraction residue, it is a promising method to prepare chromium iron with the residue. The composition of residue refer to the vanadium-chromium slag which experienced vanadium extraction. Then it has been reduced under 1300oC, 1350oC and 1400oC at the reduction time of 1h, 2h and 3h respectively. The reduced sample have been smelting separated by induction furnace. Then the content of chromium and iron in metallic phase have been investigated by inductively-coupled plasma spectrometer. The results indicate that chromium iron carbide (Cr, Fe)3C7 is intermediate phase and titanium has been reduced during reduction process. When the sample has been reduced under 1400oC at the reduction time of 3h, metallic phase become the dominate phase, and reduction reaction has been almost completed. Moreover, the content of the metal phase reaches 10.19%.
E-31: Experimental Study on the Electrical Conductivity of CaO-SiO2-Al2O3-CaF2-Na2O-MgO Slag System: Li Zhao1; Yu Wang1; Shu-chao Wang1; 1Chongqing University
With the development of electromagnetic technique, mould slag as the key functional material in the process of continuous casting, its electrical conductivity change will directly affect the properties and behavior of mould slag, so to research the typical components of mould slag on the changes of electrical conductivity is of great significance. In this experiment, using the electrochemical workstation, to study the effects of each component of CaO-SiO2-Al2O3-CaF2-Na2O-MgO slag system on electrical conductivity. The results show that when the Al2O3 content increased from 3.5% to 6.0%, the conductivity decreases gradually; CaF2 content increased from 2.0% to 7.0%, the conductivity increases gradually; Na2O content increased from 2.0% to 7.0%, the conductivity increases gradually; MgO style content increased from 2.0% to 4.5%, the conductivity increased gradually.
E-32: Decarburization of Spent Petrochemical Catalysts via Microwave Oxidation Roasting: Bingguo Liu1; Peng Liu1; Libo Zhang1; Haigang Dong2; Jinhui Peng1; 1Kunming University of Science and Technology; 2State Key Laboratory of Advanced Technology for Comprehensive Utilization of Platinum Metals
Parameters of technique to decarburization of spent petrochemical catalysts via microwave oxidation roasting were investigated base on the thermogravimetric analysis. The results showed that the decarburization rate of spent petrochemical catalysts was significantly affected by roasting temperature and sample thickness in the range studied. The optimized conditions were as follows: roasting temperature 600℃, roasting time 40 min and 2cm, respectively. The decarburization rate of spent petrochemical catalysts was 99.5% under the optimization conditions. The residuum after decarburization was characterized by FE-SEM. Energy spectrum reveals that it is feasible to decarburization by microwave oxidation roasting from spent petrochemical catalysts.
E-33: Removal of Methylene Blue by Copper Ion-modified Eupatorium Adenophorum-based Activated Carbon: Kinetic, Thermodynamics, Isotherm Investigation: Li Chunyang1; Zhang Libo1; Xia Hongying1; Cheng Song1; Shu Jianhua1; 1Kunming University of Technology and Science
Simultaneous adsorption of methylene blue dye onto copper ion-modified eupatorium adenophorum-based activated carbon was studied in this research. Several parameters such as loading temperature, heating time, heating rate, ionic concentration and dipping time were found to have vital influence on adsorption properties and the obtained optimum experimental condition for the parameters i.e. loading temperature, heating time, heating rate, ionic concentration, dipping time were 450℃, 40min, 25℃/min, 0.1mol/L, 12h, respectively. The modified activated carbon that used to be adsorbent was characterized by means of nitrogen sorption at 77K, FT-IR were utilized to elucidate which functional groups existed after modifying and what externality properties it possessed. The experimental isothermal data revealed the suitability and applicability of the Langmuir isotherm model and kinetic data was in good agreement with pseudo-second-order equation model.
E-34: Effects of Blowing Conditions on the Dispersion States of Materials Charged into Bottom Blown Oxygen Smelting Furnace: Dongxing Wang1; Yan Liu1; Zhang Ting'an1; Xiaolong Li1; 1Northeastern University
Recent years, bottom blown oxygen copper smelting process has been widely used in China. Besides many advantages such as autothermal operation, this technology is still in developing stage. This topic aims at promoting the dispersion of materials charged into the bottom blown smelting furnace used in the process. Based on the similarity theory, a 1/5 scaled physical model of smelting furnace was constructed. Polypropene particles are used as charged materials. High-speed camera was used to record the phenomenon of the particles dispersion under different gas-flow rates, nozzle diameters and installation angles of nozzles. Image processing software was used for obtaining the particles concentration under different conditions. Results show that when the gas flow rate increases, charged materials disperse better. With the same gas flow, the increasing of nozzle diameter promotes the dispersion effect of materials. The effects of installation angles are opposite for nozzles with diameter of 2.5 and 5.92mm.
E-35: Characteristic of Subsurface Hooks in Slabs And Behavior of Inclusions Entrapment at High Speed Continuous Casting: Peng Yuan1; Haibo Li1; Chenxi Ji1; Bin Chen1; 1Shougang Research Institute of Technology
On the basis of using electromagnetic brake to prevent the mold powder entrapment, high speed continuous casting not only can improve the production efficiency, but also can improve the quality of slabs. Inclusions in the surface of slabs were analyzed by Aspex scanning electron microscopy, and characteristic of subsurface hooks in slabs were also investigated. Then the changing law of inclusions and hooks characters were achieved at different casting speeds. The results show that the depth and length of hooks decrease with the casting speed increasing. Inclusions larger than 200μm are entrapped by hooks, and the entrapment behavior of inclusions with the size of 50~200μm is influenced by forces acting on inclusions at the solidifying front. With the increasing of casting speed, the washing force becomes large and the entrapping force becomes small, and therefore the number of entrapped inclusions decreases.
E-36: Assessment of Crystallization Kinetic Study of Phosphate–enriched Phase in CaO–SiO2–FeO–P2O5–Fe2O3 Steelmaking Slags: Jin-yan Li1; Zhang Mei1; Guo Min1; 1University of Science and Technology Beijing
The iso-thermal crystallization kinetic of phosphate–enriched phase has been investigated through JMAK equation in the rapidly quenched CaO–SiO2–FeO–Fe2O3–P2O5 steelmaking slags with different cooling process. From the statistically analyzed by image manipulation software Image-pro-plus and the scanning electron microscope (SEM) images, the crystallized fraction of phosphate–enriched phase was calculated to determine the values of Avrami exponent n and the temperature-dependent constant k(T) in the slags. Thus, the apparent activation energy E was obtained. The results show that the average of Avrami exponent n is about 0.472 during the crystallization of phosphate–enriched phase and the apparent activation energy E for crystallization in this study is about –278.44 KJ/mol. The apparent activation energy E for crystallization was obtained by using seven different constant k(T), where the error of Van’t Hoff’s No. 2 model (M7) is minimum and its error of the apparent activation energy E calculated with Arrhennius equation is maximum. The determined rate constant equations k(T) of M7 can be described as lnk=53.80+11163.69/T-7.49lnT-0.005T.
E-37: Research on the Flow Behavior of Molten Slag through Pore: Yingli Liu1; Qingguo Xue1; Jingsong Wang1; Guang Wang1; 1University of Science and Technology Beijing
In the dropping zone, primary slag absorbing ash of pulverized coal and coke become to be intermediate slag. Duo to viscosity and surface tension of slag and the pore between cokes, some slag remained in coke layer and affected the permeability of blast furnace. The flow behavior of slag with different basicity (0.55～1.10)and Al/Si (0.35～0.50) were studied. Meanwhile, the viscosity and surface tension of slag were calculated. The results showed that, with the basicity rising of slag, surface tension increased and viscosity decreased. With the Al/Si rising, surface tension and viscosity increased. The smallest pore that all slag pass through was 4.5mm. However, the height between slag and the bottom of crucible indicated that the ability of slag to pass through pore were weakened with the increasing of basicity and Al/Si. Namely, slag after absorbing ash from fuel become difficult to pass through coke layer.
E-38: Removal of Cd(II) Ion from Aqueous Solution by Adsorption on Wasted Low Grade Phosphorus-containing Iron Ore: Xiaoli Yuan1; Wentang Xia1; Juan An1; Xiaoyan Xiang1; Xuejiao Zhou1; Jianguo Yin1; Wenqiang Yang1; 1Chongqing University of Science and Technology
Low grade phosphorus-containing iron ore (LGPIO), a raw and wasted industrial solid material was used as an adsorbent to remove Cd(II) ion from wastewater. The effects of initial pH value, adsorptive time, initial Cd(II) ion concentration, adsorptive temperature and LGPIO dosage on the Cd(II) ion removal efficiency were studied. The results show that the Cd(II) ion removal efficiencies exceed 99.81% under the conditions of pH value 6, temperature 20oC, adsorptive time 60 min, initial Cd(II) ion concentration 50 mg/L, particle size 0.074~0.15 mm, adsorbent dosage 50 g/L and stirring speed 290 r/min. After Cd(II) ion removal reaction, the Cd(II) ion concentrations completely accord with the requirement of national discharge standard of water pollutants for cadmium and zinc industry(GB 20466-2010) (TCd(II)=0.1mg/L) in China. Therefore, it can be concluded that LGPIO is a new low-cost adsorbent which is suitable for the adsorption of Cd(II) ion from wastewater.
E-39: One-step Extraction of Lead from Spent Lead-acid Battery Paste via Reductive Sulfur-fixing Smelting:Thermodynamic Analysis: Yun Li1; Chaobo Tang1; Yongming Chen1; Shenghai Yang1; Lulu Guo1; Jing He1; Motang Tang1; 1Central South University
A new innovative process for one-step and cleaner extraction of lead from spent lead-acid battery by reductive sulfur-fixing smelting was presented. This paper summarized and discussed several potential sulfur-fixing agents and molten salts which can be used in this new technique. Thermodynamic analysis involving reaction mechanism, ∆G_T and predominance-area diagrams of different smelting systems were performed, respectively. The results proved the technical feasibility and high-efficiency of this process. Copper oxide ash (CuO), zinc oxide dust (ZnO) and iron oxide bearing residues (FexOy) can be used as sulfur-fixing agent to extract lead through exchange reactions. Sulfur-fixed efficiency of CuO, ZnO and FeO decrease slightly in turn. Sulfur contained in PbSO4 is fixed in form of Cu2S, ZnS and FeS respectively which avoids SO2 emission. The addition of molten salt can significantly decrease temperature of reductive sulfur-fixing reactions. Molten salt can be regenerated and recycled in smelting system after filtering solid residues.
E-40: Influence of Hot Charge on Blast Furnace Performance for Iron Making: Huiqing Tang1; 1University of Science and Technology Beijing
Energy-saving analysis on hot burden charging of blast funace ironmaking was conducted by numerical simulation in this paper. The developed model was validated by comparing calculation results with actual production data, the performance of the blast furnace are simulated under the hot burden charging temperature from 300K to 1000K. Results reveal that the hot charging temperature of 600K，approximately 30kg/thm coke could be saved.
E-43: Molecular Dynamics Study of the Structural Properties with Varying B2O3/SiO2 Ratios in the System CaO–SiO2–B2O3: Xiao-Ping Liang1; Wei-Tong Du2; Yu Wang1; 1Chongqing University; 2Chongqing University
The structural properties for ternary molten CaO–SiO2–B2O3 system with varying B2O3/SiO2 ratios at a fixed CaO content were calculated by molecular dynamics (MD) simulation. The simulation results revealed that with the increasing of B2O3/SiO2 mole ratio, the bond length of B–O was approximately constant at 1.35 Ċ, and the coordination number for B (CNB–O) was observed to vary from 3.40 to 3.51, and the average angle of O–B–O increases from 105° to nearly 120°, implying that the geometric stability of structure is reducing sharply. Also Q3 and Q4 tetrahedral species (tetrahedron with three and four bridging oxygens respectively) decrease with the increasing of B2O3/SiO2 mole ratio, and the degree of polymerization decrease linearly from 1.58 to 0.04, suggesting that B2O3 may behave as a network-breaking basic oxide in the CaO–SiO2–B2O3 system.
E-44: Influence of Converter Slag on Decomposition Behavior of Limestone during BOF Steelmaking Process: Hua Lu1; Wen-Wen Mao1; Chen-Xiao Li1; Hong Li1; 1University of Science and Technology Beijing
Directly charging limestone into slag in BOF is a newly emerging technique which broke through the traditional BOF slagging principle. It is necessary to study the decomposition behavior of CaCO3 in converter slag during BOF steelmaking. FeOx, SiO2, MnOx and pre-melting slags were mixed with CaCO3 according to a certain proportion to simulate the environment of limestone in converter slag. TG-DTA results indicated that slag with individual component, including FeOx, SiO2 and MnOx, all had obvious effects on reducing the decomposition temperature of CaCO3. Pre-melting slags with multiple components had further reducing effects than individual component. XRD results showed converter slag component would react with decomposition product of CaCO3 and generate solid solution or oxide, reducing the activity of CaO and the decomposition temperature of CaCO3.
E-45: Study on the Effect of Liquid Core Reduction
on Mechanical Properties of 50Mn2V Hot-rolled Strip: Ming-feng Ye1; Guang-liang Wu1; Jian-hua Ren1; 1Central South University
Experimental research on blade steel 50Mn2V was conducted in a steel plant’s CSP process with liquid core reduction (LCR)，the effects of mechanical properties showed in two different processes (with LCR and without LCR) were discussed. Results indicated that the mechanical properties were enhanced in a small degree when using LCR. Under the same conditions of composition，the average yield strength can be improved 40MPa with LCR，the tensile strength can be increased by 20MPa approximately，the elongation almost kept unchanged.
E-46: Comparison of the Ringing Characteristics between Acid and Alkaline Iron Ore Pellets Powder in Kiln: Yong-Bin Yang1; Xin Min1; Qian Li1; Bin Xu1; Tao Jiang1; Xiao-liang Liu1; Yan Zhang1; 1Central South University
The ringing characteristics of acid and alkaline pellet scrap powder in kiln were studied by the thermodynamic calculation using software FactSage7.0, roasting experiments using briquetting method and analyses of SEM-EDS. The thermodynamic calculation showed that liquid phase could be generated from alkaline pellet powder at a lower temperature and the amount of formed liquid phase at the same temperature was much more than that from acid pellet powder. Roasting experiments indicated that the compressive strength of alkaline pellet powder briquettes were also higher than that of acid pellet powder briquettes. Additionally, the analyses of SEM-EDS suggested that the alkaline pellet powder briquette presented more liquid phase and a more compact structure comparing with the acid pellet powder briquette, which was consistent with the results of thermodynamic calculation and roasting experiments. Hence, in comparison with acid pellet powder, alkaline pellet powder is much easier to ring in the kiln.
E-47: Ab-initio Molecular Dynamics Simulation of High Temperature Sulfur Evaporating Behavior in Vacuum: Fansong Liu1; Yuezhen Zhou1; Dachun Liu1; Xiumin Chen1; Chongfang Yang1; Wei Li1; 1Kunming University of Science and Technology
Ab initio molecular dynamics (AIMD) simulation was used to study the structures, stabilities and evaporation properties of sulfur at high temperature and vacuum. The simulation results show that S-S bond tend to fracture in sulfur supercell, when sulfur supercell structure has transformed from ring to open-chain. It was also found that the sulfur molecules which consisted by relatively more atoms were intended to form sulfur molecules with less atoms, and its stabilities were reduced.
E-48: Precipitation of Arsenic as Scorodite both at Atmospheric and Hydrothermal Conditions: Zhonglin Ye1; 1Yunnan Copper Smelting & Processing Complex
The removal of arsenic from arsenic-bearing waste water is an urgent problem in hydrometallurgical processing of non-ferrous metals. Precipitation of arsenic as its environmental friendly precipitate, scorodite both at atmospheric and hydrothermal conditions is of great interesting. Factors of initial arsenic concentration, initial Fe/As molar ratio, temperature, initial pH, agitation speed and retention time are studied on effect of arsenic and iron removal rate and precipitate composition. The experimental results indicates that crystalline scorodite are formed both at under the hydrothermal conditions, lower initial pH, longer retention time and lower Fe/As molar ratio is more suitable for the synthesis of better crystalline scorodite and high arsenic and iron removal rate.
E-49: An Energy Consumption Theory for Coke Degradation in Blast Furnace: Qihang Liu1; 1Xi'an University of Architecture and Technology
There is considerable interest of coke degradation in blast furnace which has a significant influence on the actual production.This work proposed an energy consumption theory regarding for the relationship between energy consumption and reacted coke degradation in blast furnace based on the two kinds of volume hypothesis. The crucial factors affecting coke fines generation such as carbon loss rate, local reaction degree and initial porosity were introduced into volume hypothesis. The theory in this work gives an energy consumption formula indicate that the restrictive relationship among coke degradation rate, the size and smelting intensity of BF, gasification conditions, initial porosity of coke etc. should be satisfied for BF in the actual production process.
E-50: Study on the Influence of Materials on Heat Transfer Characteristics of Blast Furnace Cooling Staves: Fengguang Li1; 1Hubei University of Automotive Technology
Cooling stave is one of the most important equipment of blast furnace for iron making. The heat transfer performance and service life of the cooling stave, to a large extent, determines the efficiency and economy of the iron making process. In this paper, a 3-D heat transfer model of cooling stave was founded by ANSYS based on FEM theory, and the heat transfer characteristics of cooling staves which were made of different materials (cast iron, cast steel, copper, and steel-copper) were analyzed. Then several suggestions on choosing material of cooling staves were given according to the calculation results and the actual working conditions of the cooling staves.
E-51: Microwave Assisted Regeneration of Spent Activated Carbon from Paracetamol Wastewater Plant Using Steam: Song Cheng1; 1Kunming University of Science and Technology
Abstract: Spent activated carbon from paracetamol wastewater plant was regenerated via microwave heating using steam. The conditions of this experiment are regeneration time, regeneration temperature and steam flow rate. The methylene blue (MB) adsorption number and yield are 196.5mg/g and 68.25%, respectively under the optimal conditions. The pore structure parameters of regenerated activated carbon such as the BET surface area and total pore volume are 1085.3m2/g and 1.09 ml/g respectively. The regenerated activated carbon and spent activated carbon were characterized by SEM and N2 adsorption. The results of SEM showed that surface impurities of regenerated activated carbon are cleaned and pores number increase obviously. N2 adsorption results indicate that BET surface area and total pore volume of regeneration activated carbon are obvious increase.