钢铁钒钛

Study on Vanadium Extraction from Converter Vanadium-bearing Slag by Oxygen Pressure Acid-leaching

Zhang Guoquan, Zhang Tingan, Lü Guozhi, Zhang Ying, Liu Yan, Liu Zhuolin

2014, 35(3): 1-4. doi: 10.7513/j.issn.1004-7638.2014.03.001

Abstract(22) PDF(0)

Abstract:
For researching a more efficient vanadium extraction process,the processes of atmospheric pressure acid-leaching without roasting,none salt roasting with atmospheric pressure acid-leaching and oxygen pressure acid-leaching without roasting were researched.The results indicate that:During the atmospheric pressure acid-leaching without roasting process,the leaching rate of vanadium increases with the enhancement of temperature and initial acid concentration,but the content of vanadium in the leaching residue is still high and the degree of utilization of vanadium slag is not enough;During the none salt roasting with atmospheric pressure acid-leaching process,the transformation of spinel phase in the roasting process is the key step for the vanadium extraction;In the process of oxygen pressure acid-leaching without roasting,under the conditions of initial acid concentration of 150 g/L,the oxygen partial pressure of 0.6 MPa and liquid-solid ratio of 8:1 at 110℃ for 45 min,the vanadium leaching rate is about 92%.

Study on Separation of Vanadium and Chromium by Ion Exchange Resin

Li Hongyi, Li Cui, Zhang Meng, Xie Bing

2014, 35(3): 5-9. doi: 10.7513/j.issn.1004-7638.2014.03.002

Abstract(29) PDF(0)

Abstract:
Vanadium and chromium respectively exist as V(V) and Cr(VI) in the waste water produced in the procedure of vanadium precipitation.It is a particularly significant issue to reduce the environmental pollution by the waste water and recover the valuable metals simultaneously.An anion exchange resin was used to realize the separation and extraction of vanadium and chromium from the waste water by absorbing V(V) selectively.Before adsorption,V(V) and Cr(VI) were respectively reduced to V(IV) and Cr(III),afterwards V(IV) was oxidized to V(V) while Cr(III) remained to exist in the form of Cr³⁺.The dependence of vanadium adsorption on temperature,solution pH,concentration of ions and contacting time were investigated,and the adsorption conditions were optimized.The results show that the purity of vanadium and chromium final products are respectively about 96% and 93%,and the recovery rate of vanadium and chromium are 72% and 95%,respectively.

Fabrication of Vanadium Sesquioxide Powder by Hydrolysis Method

Tong Junfeng, Zhao Hongyu, Li Zhengxin

2014, 35(3): 10-13. doi: 10.7513/j.issn.1004-7638.2014.03.003

Abstract(31) PDF(0)

Abstract:
V₂O₃ powder was prepared by hydrolyzing VOSO₄ without adding reducing agent.The effects of atmosphere and temperature on the sintering behavior were studied.The products were analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM) and laser particle size analyzer.The results show that different products are obtained with 5℃/min heating rate in different atmospheres from room temperature to 800℃ and with insulation for 3 h.The product is V₄O₇ powder in argon atmosphere with flow rate of 160 mL/min,while the V₂O₃ powder is obtained in vacuum,with average diameter of 452 nm after being grinded in agate mortar for 20 min.The optimum pH for vanadium hydroxide by hydrolyzing VOSO₄ is approximately 4.

Optimization Research on Vacuum Distillation Process for Titanium Sponge Preparation by Magnesium Thermal Reduction

Liu Bin

2014, 35(3): 14-18. doi: 10.7513/j.issn.1004-7638.2014.03.004

Abstract(41) PDF(2)

Abstract:
According to the technology problems of the intermediate channels blockage in distillation process and the over standard of chloridion in products during the titanium sponge production by magnesium thermal reduction,the optimizations of system pressure,temperature and time in distillation process were conducted.Thermodynamic analysis results show that the relative volatility of Mg and MgCl₂ to Ti is more than 2.21 x 10¹¹ when the distillation temperature is 900~1 000℃.Distillation process optimization experiments show that the favorable system pressure of vacuum distillation process is not more than 4 Pa,and the preheating temperature is 750~800℃,the early stage of the preheating time 1~2.5 h and continuous water spray time in the initial distillation process 30~36 h.After the optimizations,the product grade rate of titanium sponge improves significantly,and the titanium sponge above grade 0 increases by 16.54% on average while the ratio of substandard titanium decreases by 6.4%.

Controllable Synthesis and Photocatalytic Properties of TiO₂ Microspheres with Core-shell Structure

Dai Hai, Meng Jialin, Ren Weian, Wen Xiaogang

2014, 35(3): 19-22. doi: 10.7513/j.issn.1004-7638.2014.03.005

Abstract(32) PDF(1)

Abstract:
TiO₂ microspheres with different morphology were synthesized by a simple hydrothermal method.The as-prepared samples were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM).The photocatalytic activities of the samples for methyl orange degradation were studied.The results indicate that the core-shell structure TiO₂ microspheres have favorable photocatalytic performance.Under the UV light for 1 h,the degradation rate of the methyl orange reaches to 90%,that is 20% faster than the others when the TiO₂ samples have different morphology.

Hexagram-shaped V₂O₃ Nanoparticles: Synthesis and Characterization

Cao Yirong, Luo Xiaoxiao, Lin Shengxuan

2014, 35(3): 23-27. doi: 10.7513/j.issn.1004-7638.2014.03.006

Abstract(21) PDF(0)

Abstract:
Hexagram-shaped V₂O₃ nanoparticles were synthesized by annealing hexagram-shaped NH₄V₃(OH)₆(SO₄)₂ precursor prepared through hydrothermal method.Both the precursor and annealed samples were characterized,and the formation mechanism of hexagram-shaped nanostructure NH₄V₃(OH)₆(SO₄)₂ was investigated by SEM characterization at different periods during the reaction.The results show that the dimensions of precursor particles are about 600 nm in axial direction,more than 200 nm for each branch and less than 100 nm in the width,respectively.After annealing,the dimensions of V₂O₃ particles are below 300 nm in axial direction and about 100 nm for each branch and no more than 50 nm in the width,respectively.Electrochemical measurements show that the discharge specific capacity of hexagram-shaped V₂O₃ reaches 77 mAh/g at a current density of 50 mAh/g with the cutoff voltage range 3.0~1.5 V,and remains at 42 mAh/g after 20 cycles.

Experimental Study on Preparation of Potassium Metavanadate by Ammonium Polyvanadate

Yin Zhaoqian

2014, 35(3): 28-32. doi: 10.7513/j.issn.1004-7638.2014.03.007

Abstract(24) PDF(0)

Abstract:
Potassium metavanadate was prepared by ammonium polyvanadate(APV).The effects of crystallization method and vanadium concentration on the compositions of potassium metavanadate were investigated.The results show that the incubation time is 15~20 h,the filtrate residue vanadium than 25 g/L under natural crystallization conditions,and the crystallization time is 5~10 min and the content of residual vanadium in filtrate is less than 2.5 g/L,and the crystallization ratio is more than 97% with crystallization promoter agent.Potassium metavanadate of 1.5 tons,with the compositions of TV ≥ 36%,K ≥ 28%,Na < 0.05% and Fe < 0.02%,were synthesized with crystallization promoter agent by industrial test which achieves the expected goals.

Study on Modification of TiAl Alloy for Automotive Turbocharger

Chen Jiaguo, Zong Yaping

2014, 35(3): 33-36. doi: 10.7513/j.issn.1004-7638.2014.03.008

Abstract(34) PDF(0)

Abstract:
The Ti-47.5Al-2.5V-1Cr-0.1Y alloy samples for automobile turbocharger were respectively prepared by common casting and two-step method,and the microstructures,mechanical properties,corrosion resistance and fatigue resistance for the samples by the 2 methods mentioned above were tested and contrastively analyzed.The results show that the crystalline grain can be refined and the casting defects such as pores and microporosity are avoided,and the mechanical properties,corrosion resistance and fatigue resistance of the alloy are improved by two-step method,compared to the common casting method.For sample prepared by the two-step method,the tensile strength and impact absorbing energy at room temperature respectively increases by 33.28% and 33.33%,the fatigue life increases by 95.34% and the corrosion potential changes 236 mV to the positive direction.

Research on Process Parameters of Electron Beam Rapid Prototyping for Titanium Alloy

Song Jian, Wang Ming

2014, 35(3): 37-41. doi: 10.7513/j.issn.1004-7638.2014.03.009

Abstract(34) PDF(1)

Abstract:
This paper applied different process parameters for the study of electron beam rapid prototyping TC18 titanium alloy sheet and carried out the testing and comparative analysis of mechanical properties,high temperature oxidation resistance and corrosion resistance for the alloy.The results show that,except for the scanning time,the factors of beam current,focusing current,accelerating voltage and the thickness of each metal powder layer have major impacts on the mechanical properties,high temperature oxidation resistance and corrosion resistance of the TC18 titanium alloy.Both the tensile strength and impact ductility of TC18 titanium alloy increase and then decrease with the enhancement of any one of the three parameters:beam current from 3 mA to 9 mA,focusing current from 550 mA to 650 mA,thickness of each metal powder layer from 0.2 mm to 1.0 mm.The optimal process parameters are the beam current of 6 mA,focusing current of 600 mA,scanning time of 2 s,accelerating voltage of 55 kV and the thickness of each metal powder layer of 0.6 mm.

Experimental Researches on Removal of Chloride in Blast Furnace Slag after Extracting Titanium

Long Panzhong

2014, 35(3): 42-45. doi: 10.7513/j.issn.1004-7638.2014.03.010

Abstract(15) PDF(0)

Abstract:
The chloride-containing tailings produced in the process of titanium extraction from high titanium blast furnace slag were analyzed.For achieving the non-hazardous treatment,the technologies of chloride removal for tailings after extracting titanium by washing and high-temperature calcination were investigated.The results show that the 4 processes of washing,calcination with trace amount of water,washing-calcination and multistage washing-calcination all can remove chloride in the tailings to a certain content,of which the chloride is most effectively removed and the tailings are made satisfying the national construction industry standards by multistage washing-calcination process.It is expected that the tailings after extracting titanium can be extensively and synthetically utilized in construction industry by the technologies mentioned above.

Research on Process Mineralogy of an Ilmenite in Myanmar

Wang Mo, Zhang Hanping, Xie Feng, Lei Ting

2014, 35(3): 46-49. doi: 10.7513/j.issn.1004-7638.2014.03.011

Abstract(15) PDF(0)

Abstract:
Through multi-element analysis,XRD,SEM,microscopic analysis and other measurement methods,the process mineralogical studies on an ilmenite in Myanmar were carried out to identify the chemical composition,mineral composition,grain size distribution and dissemination characteristics of the ore.The factors affecting mineral processing were discovered,based on the research results of process mineralogy of the ilmenite.The mineral processing including strong stirring and desliming for sufficient dissociation of ilmenite,magnetite,maghemite and rutile was proposed,which provides the basis for beneficiation of the ore.

Use of Vanadium in Long Steel Products

Li Yu, Mierben Dawei

2014, 35(3): 50-54. doi: 10.7513/j.issn.1004-7638.2014.03.012

Abstract(18) PDF(0)

Abstract:
Vanadium has been widely used in long steel products such as forging grades,reinforcing bars,sections,tubes,rails,springs and wire rods.Vanadium is the preferred addition in long steel products because of the much higher solubility of its carbonitrides in austenite and lower sensitivity to carbon level compared to niobium and titanium.Vanadium provides precipitation strengthening and grain refinement,resulting in good combinations of strength and toughness.The precipitation strengthening can be maximized by management of nitrogen level and the preferential precipitation of vanadium with nitrogen also minimizes the risk of nitrogen strain aging.In addition,vanadium enables desired strength levels to be attained at lower carbon content,which is beneficial for ductility and weldability.Furthermore,vanadium contributes to temper resistance and provides secondary hardening for quenched and tempered steels.Fine vanadium carbides also act as strong trap sites for diffusible hydrogen,leading to good delayed fracture resistance.The relatively low solution temperature of vanadium carbonitirdes permits the use of energy efficient,low reheating temperatures.Conventional hot rolling or forging with high finish working temperatures,which are inevitable for production of long steel products,can be used for vanadium microalloyed steels to achieve the required mechanical properties and service performance.In addition,the properties of vanadium microalloyed steels are relatively insensitive to changes in processing conditions.

Production Status and Development Trend of Vanadium Product in World in Recent Years

Liu Shuqing

2014, 35(3): 55-62. doi: 10.7513/j.issn.1004-7638.2014.03.013

Abstract(19) PDF(2)

Abstract:
Production status and development trend of vanadium-bearing iron ore concentrate,vanadium slag,ferrovanadium and nitrovan in world in recent years are described.The production of vanadium product,product mix,financial results and trends for Evraz in Russia,Xstrata in Switzerland,Panzhihua Steel,Chengde Iron and Steel of HIBIS are described.The follow conclusions are obtained through analysis:the production of vanadium is very centralized;China is the country of most vanadium production;vanadium industry is faced the problems that the production capacity of vanadium expand is too much,the market of iron and steel is too weak,the substitute-niobium influences the market of vanadium;vanadium industry is faced the opportunity that the V microalloying high tensile steel bar is increasing the consumption,vanadium redox flow battery develops very rapidly and the commercially production is hopeful.

Researches on Vanadium-titanium Magnetite Concentrates by Composite Agglomeration Process

Wan Xinyu, Lü Qing, Zhang Shuhui, Sun Yanqin

2014, 35(3): 63-68. doi: 10.7513/j.issn.1004-7638.2014.03.014

Abstract(17) PDF(0)

Abstract:
Vanadium-titanium magnetite is characterized by high content of TiO₂,low content of SiO₂ and the resulting sinter is at low tumbler strength and RDI.In this paper a composite agglomeration process(CAP) was investigated and the resulting sinter performance was compared with conventional sintering process,The research indicated that when raw materials proportioning was kept constant,RDI_+3.15 increased by 5.23%~17.4%,and the tumbler strength index excessed 55% after the implementation of the composite agglomeration process.Compared with conventional sintering,CAP led to the material bed depth increasing from 600 mm to 1 000 mm improvement of vanadium-titanium sinter RDI_+3.15 indicators as well as higher production efficiency.

Influence of MgO on Structure of Vanadium-titanium Sinter

Li Zhimin, Liu Lina, Duan Shan, Han Xiuli

2014, 35(3): 69-73. doi: 10.7513/j.issn.1004-7638.2014.03.015

Abstract(19) PDF(0)

Abstract:
The composition and microstructure of vanadium-titanium sinters with different MgO contents were determined by means of polarization microscope.The result shows that,as MgO content increased,the microstructure transferred from melting corrosion to granular structure.Meanwhile,he content of metal phase increased and the content of binder phase decreased.The tumbler strength of sinter decreased,and RDI of sinter improved.The content of MgO in sinter raw material of Chengde Iron&Steel Corporation is proposed at around 2.0%.

Effect of Calcium Chloride on Low Temperature Reduction Process of Iron Oxide Charge in Blast Furnace

Liu Xiaojie, Zhang Shuhui, Sun Yanqin, Lü Qing, Chen Zhenfei

2014, 35(3): 74-77. doi: 10.7513/j.issn.1004-7638.2014.03.016

Abstract(9) PDF(0)

Abstract:
The technology of spraying sinter with CaCl₂ can improve the RDI while impacts the metallurgy performance of other raw materials in blast furnace.In order to understand the influence of CaCl₂ on RDI and weight loss rate of iron ore during their low temperature reduction process,the sinter and pellet had been investigated.The results showed that RDI_+3.15 of sinter after CaCl₂ solution treated increased and the weight loss rate decreased at low temperature(<900℃).Especially in the temperature range of 500~700℃,CaCl₂ exearted considerable inhibition effect on the reduction of sinter and obviously affected the reduction process of pellet.For the pellet the effect was weaken gradually when temperature exceeding 700℃.

Research on Process Parameters Optimization for Slab Continuous Casting Mold by Water Modeling

Xiong Ye, Cheng Zewei, Chen Weiqing, Tang Shengbin, Liu Li

2014, 35(3): 78-82. doi: 10.7513/j.issn.1004-7638.2014.03.017

Abstract(17) PDF(0)

Abstract:
The effects of casting speed,width of mold,depth of submerged entry nozzle,nozzle port angle,and shape of port nozzle on the flow field and the surface flow fluctuation of the slab continuous caster from a steelmaking plant were investigated by means of a water model test with a radio of 1:1 for the purpose of providing a guidance for improving the production parameters of the slab continuous casting mold.The results showed that the surface flow fluctuation level significantly increased with increase of the width of the mold and the casting speed.Meanwhile,the surface fluctuation could be controlled by adopting a new designed nozzle with a larger outlet angel and a deeper immersion depth and an oval port,and consequently the entrainment of slag was avoided effectively.

Research on the Effect of Slag wire on Fluid Flow in Tundish for Slab Continuous Casting

Li Ning, Bao Yanping, Lin Lu, Wang Min, Zhao Lihua

2014, 35(3): 83-87. doi: 10.7513/j.issn.1004-7638.2014.03.018

Abstract(12) PDF(0)

Abstract:
Based on the problem that slag-steel interface is strongly disturbed by the steel flow in steel impact zone thus leading to circumfluence and entrapping large inclusions into the pouring zone,installation of a slag wire in combination with original flow control devices in tundish was proposed.The effect of slag wires with different heights from the bottom and different positions from the poring zone was investigated by a water model experiment in this paper.The results show that a slag wire contributes to extending the residence time in tundish and the peak time increases by 40.9%,however,the dead zone in tundish increases by 6.2%,too.The water model experiment proved that installation of a slag wire which is 1 680 mm distance from the impact zone and 400 mm from the bottom is sufficient to suppress the dead zone in tundish and inhibit large inclusions entering the pouring zone.

Research on 20G Steel Oxide Inclusion Control and Calcium Treatment via Thermodynamics Method

Gao Ju, Ma Lixing, Han Penglong, Gao Chunqun

2014, 35(3): 88-93. doi: 10.7513/j.issn.1004-7638.2014.03.019

Abstract(20) PDF(0)

Abstract:
During the early stage of producing grade 20G steel,crack defects and macro-structure defects were frequently observed which were expected to decrease rolling qualified rate and yield.In order to solve the crack problem and to improve steel product quality,a thermodynamics method was used to determinate the relationship between equilibrium composition of possible first deoxidizing product and liquid steel compostion in the processes of first deoxidation where Al₂O₃ and SiO₂ dominate.Then activity changes of calcium,aluminum,oxygenium and sulphur had been calculated inclusion modification path had been determinated during calcium treatment which can provides theoretical basis for inclusion formation,modification and removal.

Study on Viscosity and Heat Flux Density of Casting Mold Powder at Different Temperature

Han Xiuli, Liu Lei, Zhang Han, Pan Miaomiao, Liu Lina

2014, 35(3): 94-98. doi: 10.7513/j.issn.1004-7638.2014.03.020

Abstract(28) PDF(0)

Abstract:
The viscosity and heat flux density of mold fluxes have a great impact on the quality of slab via continuous casting.Different casting mold powders used for low and medium carbon steels had been studied in term of their viscosity and heat flux density of at diferent temperatures through heat flux simulation and viscosity meter.The results show that with increasing temperature in 1 200~1 400℃,the viscositiy of mold powders for low-carbon and medium-carbon steels casting dramatically decreased until 1 350℃,however,the heat flux density of mold fluxes increased and its increment slowed down after temperature reaching 1 250℃.

Thermodynamic Research on Medium Carbon Aluminum Killed Steel by Calcium Treatment

Ma Zhifei, Zhang Yongning, Zhao Yong, Sun Yanhui, Xu Rui, Hu Wenhao

2014, 35(3): 99-104. doi: 10.7513/j.issn.1004-7638.2014.03.021

Abstract(23) PDF(0)

Abstract:
The modification mechanism of alumina,MgO·Al₂O₃ spinel and the condition of precipitation of calcium sulfide was thermodynamically analyzed in this paper.Thermodynamic calculations showed that in order to modify the alumina inclusions into liquid 12CaO·7Al₂O₃,20×10^-6 content of calcium in steel was needed when the aluminum in steel was 0.016% at 1 873 K,meanwhile,sulfur content should be no more than 0.008% to avoid the precipitation of calcium sulfide.When the content of aluminum was 0.02%,and magnesium required for MgO·Al₂O₃ spinel formation was 0.3×10^-6~10×10^-6 at 1 873 K,and 1×10^-6 calcium was sufficient to transfer spinel inclusion into liquid complex inclusions.Incompletely modified spheric inclusions where solid MgO·Al₂O₃ covered by liquid spinel would form depending on the reaction time and size of spinel inclusions.

Water Modeling Bottom Argon Blowing for 85 t Ladle Furnace

Meng Jianrong, Sun Saiyang, Sun Yanhui, Zhao Yong, Yin Xue

2014, 35(3): 105-110. doi: 10.7513/j.issn.1004-7638.2014.03.022

Abstract(9) PDF(0)

Abstract:
On the basis of similarity theory,a physical simulation system for 85 t ladle furnace had been established to simulate ladle bottom argon blowing process.The required mixing time for various position at different flow rate had been measured in order to determine the optimal location of bottom gas permeable brick and the optimal flow rate of ladle blowing.Simulation results indicated that the prototype single blowing had not achieved as-expected effect while double blowing produced a moderate effect.The optimal position of gas permeable brick was at the position of 0.5R and the gas flux was controlled in range of 300~350 L/min for single hole blowing,while.The best position of gas permeable brick was at 0.5R,with the angle of 90°,and the best blowing gas flux controlled at 350 L/min for two holes blowing.

Study of Micro-inclusion in O5 Sheet Steel Produced by BOF-RH Route

Han Penglong, Wang Ruosi, Zhang Caijun, Wang Shuoming

2014, 35(3): 111-115. doi: 10.7513/j.issn.1004-7638.2014.03.023

Abstract(15) PDF(0)

Abstract:
T[O]and[N]and the type,source,quantity and composition of micro inclusions during the production route of O5 sheet steel(pre-desulfuration → BOF → ladle slag modifier → RH → CC) had been,analyzed.The results showed that T[O]is 25.67×10^-6,[N]was27×10^-6,and the number of micro-inclusions per mm²was 2.66 in slab.The main types of micro-inclusion in casting billet were TiN,TiO₂-FeS and Al₂O₃ inclusions and their contents were 30%,24.55%,20.91% respectively.After RH vacuum break the molten steel still had high T[O],[N]and large quantity of micro-inclusions,indicating insufficient RH vacuum treatment.Floating and removal of inclusions in steel was less effective,thus improving the ladle top slag inclusions adsorption performance is one way to improve the quality of steel.slab,nearly half of micro-inclusions in slab were irregular shape,therefore,fully liquefying,aggregation and floating of micro inclusion are essential to improve the quality of O5 sheet steel.

Study of Factors Affecting Liquid Steel Rephosphorization

Zhou Chaogang, Li Jing, Wu He, Yang Kezhi, Cai Kesen, Wu Guoping, Cao Yuliang

2014, 35(3): 116-122. doi: 10.7513/j.issn.1004-7638.2014.03.024

Abstract(17) PDF(0)

Abstract:
In order to effectively control liquid steel rephosphorization,the total rephosphorization quantity in liquid steel,by slag tapping,alloy additions、smelting fluxes had been calculated,and effect of tapping conditions on total rephosphorization and rephosphorization by slag was investigated in this paper.The calculation results showed that total rephosphorization originated from slag tapping,alloying addition and fluxes,where alloy made biggest contribution to total rephosphorization and fluxes the less effect.Besides,the combination of tapping control at 1 620~1 640℃,slag basicity at 5,0.028%~0.035% carbon and more than 17% FeO effectively controlled the total rephosphorization quantity.When controlling slag basicity at 5,tapping temperature of 1 620~1 627℃,and~23% FeO,the rephosphorization by slag trapping could be effectively reduced.

2014, 35(3): 123-124.

Abstract(22) PDF(0)

Abstract:

2014 Vol. 35, No. 3