钢铁钒钛

Research on the Hydrothermal Reaction of Rich-titanium Material in the Low Concentration of Alkali Solution

Jing Tao, Wu Yafei, Chu Jinglong, Xu Hongjun, Yu Guangxin, Mei Wenhong

2015, 36(2): 1-6. doi: 10.7513/j.issn.1004-7638.2015.02.001

Abstract(47) PDF(2)

Abstract:
The hydrothermal reaction behavior of rich-titanium material in the hot Na OH solution was studied in this paper,and the effects of alkali concentration,temperature,reaction time on the conversion rate of TiO₂ were investigated by Box-Behnken central composite design and response surface analysis. The results show that the highest product conversion rate can be reached under alkali concentration 25%,temperature 186 ℃ and reaction time 4 hours. The conversion rate of product under optimal conditions was verified. The morphology and phase characterization of reaction products were analyzed by scanning electron microscopy （SEM） and X-ray powder diffraction （XRD）. Different reaction products were obtained under various conditions,and the morphologies change gradually with different conditions.

Investigation on Chloridizing 74% Titanium Slag in Molten Salts

Li Kaihua

2015, 36(2): 7-12. doi: 10.7513/j.issn.1004-7638.2015.02.002

Abstract(55) PDF(4)

Abstract:
The chloridizing experimental studies in molten salts were carried out,and the temperature of chlorination furnace,composition control of molten salts and product quality were investigated with 74% titanium slag in Panzhihua as raw materials. The technical and economic index for chlorination of titanium slag with different grades was contrastively analyzed. The results show that chloridizing 74% titanium slag in molten salts is feasible to produce titanium tetrachloride for high quality titanium sponge,and the cost per ton of titanium tetrachloride can be reduced by 98.3 Yuan compared with that of the titanium tetrachloride by 78% titanium slag.

Study on the Salt Treatment Technology of the Titanium White by Aluminum Sulfate

Ma Weiping, Xu Yuting, Du Jianqiao, Cheng Chaoyan, Wu Guangrong

2015, 36(2): 13-16. doi: 10.7513/j.issn.1004-7638.2015.02.003

Abstract(86) PDF(6)

Abstract:
The effect of aluminum sulfate as salt treatment agent on the properties of titanium dioxide initial products,mainly including the rutile conversion rate,achromatic energy,whiteness and particle morphology,was studied. The results show that aluminum sulfate is inhibitor of rutile transformation and has almost no effect on achromatic energy of titanium dioxide initial products with content of 0.08%~0.28%. The whiteness value of titanium dioxide initial products increases with increasing aluminum salt content in the range of 0.05%~0.10%,while it continuously decreases with increasing aluminum salt content in the range of 0.10%~0.50%. It is also found that addition of aluminum sulfate favors the growth of tetragonal system particles for titanium dioxide.

Study on Preparation of Sodium Metavanadate

Yin Zhaoqian, Li Qianwen, Peng Yicun, Wu Liuzhu, Pan Shaoyan

2015, 36(2): 17-23. doi: 10.7513/j.issn.1004-7638.2015.02.004

Abstract(186) PDF(9)

Abstract:
Sodium metavanadate with more than 99.5% purity was prepared through dissolution for impurities and ammonia removal and dilution crystallization,with ammonium polyvanadate as raw material.The results show that the pH value at terminal point is the main influence factor for the time of ammonia removal in the solution. The optimum parameters for dilution crystallization are as follows: concentration of vanadium 150~200 g /L,pH 7.3~8.1,volume ratio of crystallization agent and solution 1:1,and crystallization period 1 h. The yield of vanadium can reach 97.7%.

Preparation and Photocatalytic Activities of TiO₂/MCM-41 Photocatalyst

Dou Lin, Li Jianzhang, Zhong Junbo, Wang Tao, Cheng Chaozhu, Chen Jiufu, Li Minjiao

2015, 36(2): 24-27,32. doi: 10.7513/j.issn.1004-7638.2015.02.005

Abstract(62) PDF(3)

Abstract:
TiO₂/MCM-41 photocatalysts with different titania content were prepared by loading titania onto the mesopores of MCM-41 molecular sieves via a sol- gel method. The photocatalytic activities of TiO₂/MCM-41 photocatalysts were evaluated by the photocatalytic degradation of Rhodamine B aqueous solution.TiO₂/MCM-41 photocatalysts were characterized by X-ray diffraction （XRD）,UV- Vis diffuse reflectance spectroscopy and N₂ adsorption techniques. The results indicate that both the BET surface area and pore volume of TiO₂/MCM-41 photocatalyst decrease with the increase in content of loaded titania. The average crystal size of titania loaded on TiO₂/MCM-41 is smaller than that of pure titania nanoparticles. 20% TiO₂/MCM-41 photocatalyst has the highest photo- induced charge separation efficiency. Among all the photocatalysts,the 20% TiO₂/MCM-41 sample possesses the best photocatalytic activity. The h⁺ is main active species during the photocatalytic process. The photocatalytic activities of the TiO₂/MCM-41 photocatalyst depend on their adsorption abilities and the activity of titania loaded onto the MCM-41 molecular sieves.

Effect of Micro-alloying Element V and Cooling Process on C-Si-Mn Rebar

Zhang Chen, Xu Guang, Yuan Qing, He Bei

2015, 36(2): 28-32. doi: 10.7513/j.issn.1004-7638.2015.02.006

Abstract(60) PDF(2)

Abstract:
The effect of cooling process after deformation on V micro-alloyed and V-free rebar was studied. The thermal simulation experiments were carried out with different cooling processes after deformation. The transmission electron microscopy and energy spectrometer were employed to observe and analyze precipitation of the tested steels. The results show that air cooling after high temperature deformation benefits the fine VC precipitation for rebar containing V,providing a better precipitation strengthening effect.For V-free rebar,holding for 30 min at 650 ℃ after high temperature deformation is beneficial to the precipitation of nanoscale cementite. The study provides a theoretical basis for the establishment of cooling process after rolling in rebar production.

Test Method and Analysis of the Mechanical Properties of Nonlinear Elastic Ti-Nb-Ta-Zr-O Alloys

Shen Rui, Chen Feng, Yu Xinquan, Zhang Youfa

2015, 36(2): 33-38,56. doi: 10.7513/j.issn.1004-7638.2015.02.007

Abstract(70) PDF(3)

Abstract:
The elastic limit and 0.2% yield strength of nonlinear elastic materials were confirmed by cyclic loading-unloading tensile tests. The mechanical parameters of Ti- 23Nb- 0.7Ta- 2Zr- 1O,Ti-23Nb- 0.7Ta- 2Zr- 1.2O,Ti- 23Nb- 0.7Ta- 2Zr- 0.7O and Ti- 25Nb- 0.7Ta- 2Zr- 1.2O alloys were obtained by using this method. It is found that the elastic limit,yield strength and tensile strength of the alloys increase with the increase in contents of the additional elements. The elastic modulus of the alloys also increases with the plasticity deteriorating as the contents of the additional elements increase. The ratio of deformation has a significant effect on the improvement of elastic limit while slightly affects the yield strength and tensile strength of the alloys. The increase in the contents of elements and the ratio of deformation makes the tensile curve straight.

High and Low Cycle Fatigue Performance Comparison between Micro-alloyed and TMT Rebar

Surajit Kumar Paul, Pritam Kumar Rana, Debdulal Das, Sanjay Chandra, Saurabh Kundu

2015, 36(2): 39-48. doi: 10.7513/j.issn.1004-7638.2015.02.008

Abstract(67) PDF(2)

Abstract:
High and low cycle fatigue performance of micro-alloyed and TMT rebars are compared through experimental investigation. Micro-alloyed rebar shows better fatigue performance than TMT rebar. It is experimentally observed in both micro-alloyed and TMT rebars that for high and low cycle fatigue,crack initiates form the transverse rib root and propagate along the same region. From finite element simulation,it is noticed that the stress concentration takes place at the root of the transverse rib and stress triaxiality becomes higher in the same region. At the transverse rib root,tensile strain accumulation is noticed in simulation. The experimental observation is explained with the help of simulation result that fatigue crack initiate and propagate along the transverse rib root.

Research Progress of Vanadium Materials Used in Non-steel Fields

Du Guangchao

2015, 36(2): 49-56. doi: 10.7513/j.issn.1004-7638.2015.02.009

Abstract(0) PDF(2)

Abstract:

Vanadium and vanadium compounds,of which about 95% are applied to steel and alloy smelting and about 5% are used in chemical engineering and other industries,are more widely used in nonsteel fields with the development of technologies. The preparation methods and research progress of vanadium materials including vanadium catalyst,vanadium battery materials and vanadium pigments were discussed emphatically,and the applications of vanadium in nanotechnology and bio-medicine technique were summarized. The main problems in the related fields were analyzed systematically,of which high cost and weak theory research are the restrictive factors for large-scale industrialization of the vanadium materials. High-performance and low-cost vanadium materials can be prepared by combining the traditional technologies with the nanotechnology and bio-medicine technique. With the evolution of advanced techniques of characterization and the perfection of basic theories in physics and chemistry,the application prospects of vanadium in non-steel fields will be vaster.

2015, 36(2): 139-140.

Abstract(42) PDF(2)

Abstract:

Research Status of Titanium Slag and Ilmenite Resources for Preparing Rich Titanium Materials

Chang Xiaodong, He fei, Chen guo, Peng Jinhui, Zhao Wei, Liu Qianqian, Liao Xuefeng

2015, 36(2): 57-62. doi: 10.7513/j.issn.1004-7638.2015.02.009

Abstract(87) PDF(5)

Abstract:
The utilization status of titanium slag and ilmenite resources was discussed,and the domestic and overseas technologies for producing rich titanium materials by titanium slag and ilmenite were expatiated in this paper. Through comparing,it is found that the production of synthetic rutile by further impurity removal from acid dissolved titanium slag at a lower energy consumption and environmental pollution has great significance for large-scale and efficient utilization of domestic titanium resource. It is particularly important to find the replacement materials for natural rutile and develop a production process for rutile with lower energy consumption.

Study on the Track and Recycle of Vanadium in the Titanium Extraction from Blast Furnace Slag

Zhou Airan, Lu Ping

2015, 36(2): 63-67. doi: 10.7513/j.issn.1004-7638.2015.02.011

Abstract(53) PDF(3)

Abstract:
The reaction mechanism and track of vanadium were analyzed by theoretical calculation and sample detection during titanium extraction from blast furnace slag in Pangang by processes of high temperature carburization and low temperature chlorination. The results show that vanadium enters into the carbonization slag in the form of V₂O₃ during high temperature carburization of the blast furnace slag,then V₂O₃ reacts with chlorine in the process of low temperature chlorination and the product VOCl₃ enters into coarse TiCl₄. VOCl₃ transforms into solid VOCl₂ and stays in the residue through refining process. V₂O₅ satisfying the GB3283-1987 standard can be prepared by undergoing processes of calcination of the residue,salt roasting,leaching,and etc. Preliminary measurement indicates that about 50 tons of V₂O₅ can be recycled in producing every 10 000 tons of coarse TiCl₄.

Research on Conditioning Agents for Preparation of Slag Wool by Blast Furnace Slag

Sun Caijiao, Zhang Yuzhu, Li Jie, Li Junguo, Liu Chao, Hong Lukuo

2015, 36(2): 68-72,83. doi: 10.7513/j.issn.1004-7638.2015.02.012

Abstract(62) PDF(6)

Abstract:
The influences of iron tailings,basicity,contents of MgO and Al₂O₃ on the viscosity and melting temperature of the blast furnace slag were investigated in adjustment of the slag for preparation of slag wool. The results show that with increase in content of added iron tailing the characteristics of blast furnace slag transforms from short to long feature and the viscosity of the slag changes smoothly. When the addition amount of iron tailings is more than 20%,the viscosity and melting temperature of the slag increase and it is not suitable for direct preparation of slag wool. During the adjusting process for the blast furnace slag with chemical reagent,increasing basicity leads to the further transformation to short feature of slag characteristics and increase in melting temperature which is not benefit for fluidity of the slag.With increase in the content of MgO,both the viscosity and melting temperature of the blast furnace slag firstly decrease and then increase. A better fluidity of the slag can be reached with 8%~10% MgO. Because the content of Al₂O₃ in the slag is relatively small,the viscosity and melting temperature of blast furnace slag change slightly with Al₂O₃ content,which has little influence on the fluidity of the slag.

Studies on Mineralogical Characteristics of Iron Concentrates in Hongge Vanadium Titano-magnetite

Luo Jinhua, Wu Zhaoyu, Wu Enhui, Li Junhan, Liao Xianjie, Tang Rui, Yang Shaoli

2015, 36(2): 73-77. doi: 10.7513/j.issn.1004-7638.2015.02.013

Abstract(52) PDF(5)

Abstract:
The mineralogical characteristics of iron concentrates in vanadium titano-magnetite of Panzhihua Hongge area have been investigated by the methods of optical microscope,SEM,XRD,XRF etc.The measurement and observation reveal that iron concentrates mainly contain Fe,Ti,V,Cr,Si,Mg,Ca,Al,Cu,Ni,Mn,S,and some other elements. The metallic mineral in iron concentrate are major titanium magnetite and a small quantity of ilmenite and pyrrhotite. Mineralogical characteristics of iron concentrates is same as the vanadium-titanium magnetite ores,which are oikocryst and chadacryst crystal compound mineral. Iron ore concentrate has small size,and its morphology changes from granular to lamellae with particle size decreasing.

Study on Flow Properties of Low Titanium-containing Blast Furnace Slag

Huang Honghu, Lü Qing, Cao Lihua, Liu Xiaojie, Qie Yana, Ding Haichao

2015, 36(2): 78-83. doi: 10.7513/j.issn.1004-7638.2015.02.014

Abstract(44) PDF(2)

Abstract:
According to Xuan steel’s blast furnace conditions,a RTW melt properties analyzer was used to to measure slag viscosity and then to research the effect of different basicity,MgO and Al₂O₃ content on flow properties of high titanium-bearing slag of blast furnace. The results show that the slags with 4 different levels of basicity feature short slag viscosity η-T curve. With increasing slag basicity,short η-T curve feature enhanced. At the same temperature the viscosity of the slag decreases as basicity increases. MgO in a certain range is able to play the role in reducing slag viscosity,but when the MgO content exceeds 11%,the slag viscosity increases with increase of MgO content. Al₂O₃ contenthas little effect on flow properties.Theslag temperature should maintain at above 1 400 ℃,and slag is feasible with higher Al₂O₃ content.

Effect of Solid Carbon and TiC Content on the Performance of High Titanium-bearing Slag of Blast Furnace

Lü Qing, Huang Honghu, Chen Shujun, Liu Xiaojie, Sun Yanqin, Ding Haichao

2015, 36(2): 84-88. doi: 10.7513/j.issn.1004-7638.2015.02.015

Abstract(32) PDF(3)

Abstract:
According to Cheng steel blast furnace conditions,RTW melt properties analyzer had been used to measure slag viscosity,and the effect of solid carbon and slag TiC content on the performance of high titanium-bearing slag of blast furnace had been investigated. The results show that solid carbon and slag TiC content are important factors affecting titanium-slag fluidity,and they have the same impact on slag viscosity. However,TiC has greater impact than carbon on the slag metallurgical performance.

Experimental Research on the Appropriate Grinding Fineness for the Magnetic Separation of Indonesian Ilmenite Sands

Yao Chaoquan, Zhang Jianliang, Wang Zhenyang, Liu Zhengjian

2015, 36(2): 89-94. doi: 10.7513/j.issn.1004-7638.2015.02.016

Abstract(37) PDF(2)

Abstract:
In order to exploit Indonesian ilmenite sands more effectively,the properties of the ore and the process of grinding and magnetic separation test were studied by using X ray diffraction （XRD）,laser particle size analysis,scanning electron microscope energy spectrum （SEM- EDS） and other methods. The results show that both iron and titanium mainly exist in the form of titanomagnetite,ilmenite and titanohematite in the ilmenite sands. Grinding and magnetic separation methods are used for mineral processing.When the grinding fineness of- 0.074 mm accounts for 87.98 percent,the grinding efficiency expressed by growth of- 0.074 mm per minute is only 0.913 percent. Considering the cost of grinding and the index of magnetic separation,the appropriate grinding fineness of- 0.074 mm accounts for 72.76 percent where the concentrate with TFe grade of 59.5 percent,the TFe recovery of 95.70 percent,TiO₂ grade of 11.7percent,the TiO₂ recovery of 92.21 percent has been obtained when the used strength of the magnetic field is 160 m T.

In-situ Observation of Non-metallic Inclusion Precipitation in Non-ori ented Silicon Steel with Different Manganese Concentrations

Lü Xuejun, Zhang Feng, Chen Xiao, Zheng Shaobo, Zhao Dan

2015, 36(2): 95-101. doi: 10.7513/j.issn.1004-7638.2015.02.017

Abstract(43) PDF(3)

Abstract:
Based on the high temperature optical microscope,in-situ observation on precipitation of nonmetallic inclusion in non-oriented silicon steel with different manganese concentration had been carried out.The observation showed that the numbers of non-metallic inclusions was 1 000 × 10⁴/mm³ and 1 600 × 10⁴/mm³ when the manganese concentration was 0.77% and 0.32%, respectively. The precipitation temperature range of non-metallic inclusions was from 1 115 ℃ to 1 098 ℃ and from 1 068 ℃ to 1 032 ℃ for 0.77% manganese concentration,and was from 1 086 ℃ to 1 068 ℃ for 0.32% manganese concentration.For the 0.77% manganese concentration the spherical and elliposidal MnS will precipitate first,with small quantity and large size,can retard the precipitation of AlN and Cu_xS effectively; on the other hand,MnS will precipitate first and can be adopted as the core of AlN,and form the composition of MnS and AlN during the reheating and cooling processes,which is more and larger for 0.32% manganese concentration.

Effects of the Impurity Elements on the Microstructure and the Magnetic Property of the Non-oriented Silicon Steel Sheets

Chen Lingfeng, Zhao Zhiyi

2015, 36(2): 102-108. doi: 10.7513/j.issn.1004-7638.2015.02.018

Abstract(86) PDF(5)

Abstract:
In order to investigate the effects of impurities elements on the electromagnetic properties,the relationship among total inclusions amount,microstructures and electromagnetic properties of the finished steel sheets was discussed under 83 × 10^-6 and 105 × 10^-6 total amount of impurities elements C,S,O,N,Nb,V and Ti for industrial manufacture of 0.25% Si non-oriented silicon steel sheets. The results showed that the impurities elements amount will affect the type,kind,number and size of the inclusions.As the impurities elements amount increases,the numbers of single and ellipsoid MnS and Cu_xS with size range of 0~0.2 μm dramatically increases from 1 679 × 10⁴/mm³ to 2 661 × 10⁴/mm³. The fine inclusions greatly reduce magnetic induction of the finished steel sheets before and after SRA,and have little effect on core loss of the finished steel sheets before SRA,and less effects on the core loss of the finished steel sheets after SRA. with increase of continuous annealing temperature,the variation of core loss the finished steel sheets before SRA due to different impurities elements amount will decrease to zero.

Experimental Study on Performance Evaluation of Environment-friendly Insulation Coatings of Cold Rolled Non-oriented Electrical Steel Sheet

Guo Taixiong, Liu Changsheng, Dong Xueqiang, Liu Chunfu, Yuan Ping

2015, 36(2): 109-114. doi: 10.7513/j.issn.1004-7638.2015.02.019

Abstract(37) PDF(2)

Abstract:
According to the user’s process and the actual usage of the products,a series of parallel experiments have been done to explore the suitable test method and evaluation index of corrosion resistance,high temperature resistance and adhesion of environment-friendly insulation coatings on cold rolled non-oriented electrical steel sheet. The results show that the advisable evaluation method is that the corrosion area is less than 5% and 20% after six hours and twelve hours neutral salt spray test respectively. The appropriate test method of high temperature resistance of the coatings is that the laminated samples are placed in the nitrogen gas protective furnace and then heated up to 750 ℃ and held for 2 hours,the coating is qualified to be of good high temperature resistance if it has no blister,crack,flake and powder. The proper evaluation method of coating adhesion is that the sample is bend deformed with 0T,the 3M adhesive tape is stuck on the deformation area,tore off and then immersed in the 5% CuSO₄ for 5 seconds,the coating adhesion is qualified to be okay if it has no obvious crack,flake or discolor.

Research on Kinetics of Rich Hydrogen Reduction of Baiyunobo Iron Concentrate Pellets

Zhao Wenguang, Gao Qiang, Wang Yongbin, Peng Jun, An Shengli

2015, 36(2): 115-119,131. doi: 10.7513/j.issn.1004-7638.2015.02.020

Abstract(75) PDF(2)

Abstract:
The wH₂/w_CO ratio on the influence of reduction rate of Baiyun obo iron concentrate pellets was studied by homoiothermy thermogravimetric analysis （TG） method in order to solve the low utilization rate of gas and insufficient supply of heat problems in gas- solid direct reduction process.. The results showed that the reduction rate increases with increasing wH₂/w_CO ratio in 40 minutes after reduction test,and then reduce Fe₂O₃→Fe₃O₄ reaction time. Based on the gas phase diffusion and interface reaction of pellets reduction rate equations the calculated relationship of reaction rate constant and wH₂/w_CO are: k_interface=- 0.197 5 + 0.357 5wH₂/w_CO,k_spread= 0.171 01 + 0.269 7 wH₂/w_CO respectively. The activation energy of the interface reaction and the gas phase diffusion calculated by Arrhenius equation are respectively 26 kJ /mol and 44 kJ /mol,and this indicates that gas diffusion control is a restrictive link under this study condition.

Research on Solidification Behavior and Process Optimization in Single Point Straightening Rectangular Billet Continuous Casting for 65Mn Steel

Sun Ligen, Liu Yang, Ren Yingqiang, Liu Zengxun, Zhu Liguang

2015, 36(2): 120-125. doi: 10.7513/j.issn.1004-7638.2015.02.021

Abstract(41) PDF(4)

Abstract:
The heat transfer and thermal plastic models had been established based on industrial 65 Mn rectangular billet,and been used to simulate solidification temperature field and stress field in straightening point,in order to determine the effect of the distribution of temperature field and thermal stress filed on casting slab quality. The simulation results indicate that when plain carbon steel casting process is used to cast 65 Mn steel,there is a large number of liquid core retained in the straightening point,high speed casting causes a irregular distribution of stress nephogram and the stress gradient increases,this will greatly increase the internal crack occurrence; Macro observation on billet indicates that the proposed process optimization can greatly improve the quality of casting billet.

Influence of Semicharcoal Substituted for Coke Breeze on Sintering Performance

Wang Runbo, Zhang Jianliang, Wang Zhe, Yu Tao

2015, 36(2): 126-131. doi: 10.7513/j.issn.1004-7638.2015.02.022

Abstract(80) PDF(5)

Abstract:
The pot grate sintering tests were carried out with the variation of sintering fuel structure and the effect of semicharcoal substituting for coke breeze on sintering performance was investigated. The experimental result showed that the proper substitution ratio of semicharcoal for coke breeze varied with the sintering fuel structure. As the sintering fuel ratio was 4.6%,semicharcoal substitution ratio reached 20% and sinter had better performance. When fuel ratio was 5.2%,the proper substitution ratio of semicharcoal could be increased to 40%. On the circumstance that sinter performance was guaranteed,the utilization of semicharcoal as sintering fuel was an effective method to decrease sinter cost.

Physical Modeling Study of Argon Stirring Optimization on 40 t Ladle

Zhang Lechen, Bao Yanping, Guo Baoqi, Chen Jinyang, Fan Jie, Peng Shengtong

2015, 36(2): 132-138. doi: 10.7513/j.issn.1004-7638.2015.02.023

Abstract(145) PDF(12)

Abstract:
The eccentric argon stirring in stainless steel production has been studied by using geometric similarity 1:3 water model and plug model which has the same porosity to plug used in production. The mixing time,velocity of liquid steel surface and open-eye are optimized. Experiment results show that when argon stirring rate exceeds 103.1 L/h （2.1m³/h in production） the mixing time ratio （the minimum mixing time divided by mixing time at a certain flow rate） will be more than 50%. The velocity of liquid steel surface shows that storage area edge （open-eye edge） is prone to entrap slag. The diameter of open-eye is affected by ladle wall where the closer distance from porous plug to ladled wall causes the smaller diameter of open-eye. Soft blowing with plug located at 1/2R and 2/3R will ensure the open-eye ratio less than 12.4% and 10.5% respectively. The optimized flow field can prevent argon stirring process from reoxidation effectively.

2015 Vol. 36, No. 2