钢铁钒钛

Analysis on New Vanadium Technologies and Prospects of Vanadium Industry

Sun Zhaohui

2012, 33(1): 1-7.

Abstract(23) PDF(2)

Abstract:
Vanadium resources in domestic and international markets and their current utilization as well as major achievements in this field are analyzed in the present work.It is suggested that efforts should be made in China for a better and stronger vanadium industry based on rich vanadium resources,encouragement from Chinese government and relatively stable market demand for vanadium products.In the paper,it is pointed out that waste water and tailings from vanadium extraction can be recycled in the cleaner production process of vanadium oxide using vanadium-bearing titaniferous magnetite as raw material,which can solve the potential pollution problems caused by waste water with high ammonia nitrogen and sodium salt from the extraction.Cleaner and high efficient vanadium oxide production technology will be a prevailing technology in the future and the success of this project is a revolutionary technical innovation for the global vanadium industry.

State-of-art Development of Vanadium Extraction from Stone Coal

Wang Xuewen, Wang Mingyu

2012, 33(1): 8-14.

Abstract(17) PDF(1)

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The distribution of stone coal in China was introduced and processes of vanadium extraction from stone coal,including their advantages and disadvantages,were reviewed.A survey of its history and current status suggests that the development trend of vanadium extraction from stone coal could be concluded as follows: ① acid leaching would be preferred during the process of ore decomposition;② various methods could be used to separate and concentrate vanadium from the acid leaching solution;③ various products containing vanadium could be obtained;④ various valuable elements could be recovered in the process.

Efficient and Cleaner Technology of Vanadium Extraction from Vanadium Slag by Sub-molten Salt Method

Zheng Shili, Du Hao, Wang Shaona, Zhang Yi, Chen Donghui, Bai Ruiguo

2012, 33(1): 15-19.

Abstract(27) PDF(1)

Abstract:
To address the problems of low vanadium utilization rate during vanadium extraction process through vanadium slag roasting,unavailability of chromium and severe environment pollution caused by ’three wastes’,an improved efficient and cleaner technology of vanadium extraction by sub-molten salt method is introduced based on excellent physical or chemical properties of sub-molten salt and design of reaction-separation coupling process.The new sub-molten salt technology can reduce the decomposition temperature of vanadium slag to 200～400 ℃from 850 ℃ with vanadium conversion rate up to over 95% and chromium recovery rate up to over 80%,which are expected to tackle the resource and environmental problems that have bottlenecked the application of traditional vanadium extraction process.

Preparation of Vanadium Metal by Molten Salt Electrolysis

Wang Shulan, Li Shichao, Gu Dongyan

2012, 33(1): 20-23.

Abstract(23) PDF(1)

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Vanadium metal was prepared by molten salt electrolysis method using vanadium oxide as raw material.The influence of electrolysis parameters such as electrolysis temperature,electrolysis voltage,electrolysis time and the area of anode on electrolysis current was studied.Scanning electro microscope image,microanalysis and X-ray diffraction were used to characterize the composition,structure and morphology of specimens which were incompletely and completely reduced.Vanadium was obtained in the lab-scale production under the temperature of 850~900 ℃ and voltage of 2.9~3.0 V.Due to its short process flow and low temperature and simple equipment requirements,this method exhibits advantages in small scale production of vanadium.

Research on Vanadium Extraction from Vanadium-bearing Iron Concentrate by Roasting with Sodium Salt and Ion Exchange Process

Gao Guanjin, Fu Zibi, Zhang Lei

2012, 33(1): 24-29.

Abstract(29) PDF(1)

Abstract:
Using the Baima vanadium-bearing titaniferous magnetite concentrate as raw material,research on sodium roasting and ion exchange process was carried out in the laboratory.The research focused on the effects of different kinds of sodium agents,proportioning,roasting temperature and cooling condition on the roasting leaching ratio of the vanadium-bearing titaniferous magnetite concentrate and 8 rounds of clinker roasting,leaching,ion exchange and water cycling trials were carried out.The results show that the vanadium leaching rate can reach 85%~90% with Na₂CO₃ content of 3%~4%,roasting temperature of 1 150 ℃,and roasting time of 30 min.Phosphorus exhibited an enrichment during water cycling process.With enrichment to a certain extent,phosphorus should be removed for water recirculation.

Research on Vanadium Slag Roasted with Calcium Salt

CAO Peng

2012, 33(1): 30-34.

Abstract(27) PDF(4)

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Optimal parameters of vanadium slag roasted with calcium salt were obtained through orthogonal tests and single factor tests on roasting temperature,roasting time and calcium/vanadium ratio.Variation of vanadium,iron and calcium carbonate during roasting was analyzed and the effect of cooling conditions on the roasting results of vanadium slag was also discussed.The results showed that the vanadium leahcing rate could reach 87.27% with roasting temperature of 890~920 ℃,roasting time of 1.5～2.5 h,CaO/V₂O₅ ratio of 0.5～0.7 and cooling time of 40～60 min,which would be appropriate for industrial production.

Comprehensive Utilization of Chromium-bearing Vanadium Slag

Cao Hongbin, Lin Xiao, Ning Pengge, Zhang Yi

2012, 33(1): 35-39,49.

Abstract(29) PDF(1)

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Chromium-bearing vanadium slag contains vanadium,chromium and other metals which are important national strategic resources.However,they are toxic to human health,so it is significant to dispose them.Clean utilization route of chromium-bearing vanadium slag with high added value in phosphorus chemical industry is introduced in this paper.Key technologies are also researched,including research and development of new extraction system,mechanism of extraction,formation mechanism and control of the middle layer.On this basis,a seamless link between extraction and upstream and downstream units is realized,which results in a technology package of comprehensive utilization of all components in chromium-bearing vanadium slag.Furthermore,a 15 000 t/a demonstration project has been built and significant economic,social and environmental benefits have been achieved.

Research on Preparation of Formaldehyde Absorbent from Titaniferous Slag

Kong Deyu, Guan Hao, Zhang Qian, Sun Lipeng, Yang Meng

2012, 33(1): 40-43.

Abstract(27) PDF(1)

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Due to high content of TiO₂ with excellent photocatalytic degradation and wide source of availability at cheap cost,the BF titaniferous slag has drawn broad attention and interests focused on its efficient and rational utilization.The slag rich in TiO₂ was treated by process of acid leaching with hydrochloric acid（analytical reagent） for different length of time at room temperature,and then various tests such as specific surface area（SSA）,scanning electron microscope（SEM）,energy dispersive spectrum（EDS） and formaldehyde absorbing tests for the resulting absorbent were performed.According to the test results,the absorbent samples having a porous structure on the surface exhibited a good ability to absorb formaldehyde with their specific surface area increasing from 4.56 m²/g up to 105.35 m²/g;Ti content in the absorbent increased from 15.33 % up to 31.39 %（39.6% as TiO₂ content）,which implies that TiO₂ in titaniferous slag can be enriched by acid leaching.In our research,the best result turned out to be the sample dealt with HCl for 5 hours with TiO₂ content of 34.7 % and SSA of 105.35 m²/g.This sample is able to absorb 0.36 mg/g of HCHO,which is three times of activated carbon（0.12 mg/g） merchandised in the market.

Experimental Study on Sintering by Adding High Grade Vanadium-bearing Titaniferous Magnetite Concentrate at Pangang

Rao Jiating, Zhang Yixian, Yang Xiaodong, Guo Jiaguang

2012, 33(1): 44-49.

Abstract(17) PDF(1)

Abstract:
Through sintering test,sintering performance of the high grade vanadium-bearing titaniferous magnetite concentrate from Zhaoyang of Baima Mine,Pan-Xi District was studied.Taking the place of Panzhihua concentrate,the Zhaoyang concentrate exhibited good performances in sintering,such as acceleration of vertical sintering speed,increase of utilization coefficient and improvement of strength and metallurgical properties of sinter.Results of industrial experiments suggested that addition of 20 percent of Zhaoyang concentrate instead of Panhihua concentrate to the feedstock contributed to improvement of sintering performance and quality of sinter,with TFe in sinter increased by 1.16 percent,drum strength increased by 0.57 percent,and sintering solid fuel consumption decreased by 1.46 kg/t.

Influence of Al₂O₃ Content on Sintering Performance of V-bearing Titaniferous Magnetite Concentrate

Du Changkun, Luo Qingming, Mai Jichang, Yuan Xiaoli, Wan Xin, Liu Hao

2012, 33(1): 50-54.

Abstract(26) PDF(1)

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As high ratio of V-bearing titaniferous magnetite concentrate is used for the sintering feed in Sichuan Desheng Iron and Steel（Group）Company Ltd.,experiments were carried out at the laboratory to probe into the influence of Al₂O₃ on production yield and quality,reduction disintegration index at low temperature and mineral composition and microstructure of sinter.The results show that production yield,quality and reduction disintegration index at low temperature of sinter tend to downgrade with the increase of Al₂O₃ content.Considering the actuality of sintering feedstock and the production need of Sichuan Desheng Iron and Steel（Group）Company Ltd.,Al₂O₃ content in sinter must be kept within 3.2%.

Analysis on Slag Skull on BF Copper Cooling Stave for Vanadium-bearing Titaniferous Magnetite Smelting

Ji Xiulan, Liu Zengxun, Lv Qing, Zhang Zhenfeng

2012, 33(1): 55-59.

Abstract(24) PDF(1)

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A three dimensional heat transfer model of copper cooling stave is built and analysis on steady-state heat transfer is carried out by finite element software ANSYS to investigate characteristics of slag skull generated during vanadium-bearing titaniferous magnetite smelting.The results show that the thickness of slag skull increases remarkably due to higher content of iron nuggets in vanadium-bearing titaniferous BF slag,which results in decrease of slag skull stability.When the temperature thermocouple measured at the copper cooling stave is kept in the range of 60 ℃ to 80 ℃,the slag skull stability will be improved to maintain safe operation of the copper stave.Under the existing technological conditions,water velocity adjusted from 2.3 m/s to 1.5 m/s has little influence on the slag skull.

Comparative Research on Flow Pattern of Molten Steel During REDA and RH During Refining Process

HOU Peng, AI Li-qun, SHI Xin-yue, XU Shao-xia

2012, 33(1): 60-64.

Abstract(16) PDF(1)

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The flow behavior of molten steel in REDA and RH ladle during refining process was simulated by using computational fluid dynamics software.Flow field in refining process,circulation flow rate,Ar blowing route,and turbulent energy distributed on bath surface were analyzed.The results show that,compared with REDA,RH provides a stronger stirring at the bottom of ladle bath;the single dip pipe structure of REDA contributes to prolonged service life of dip pipe and enhance circulation flow of molten steel.Consequently,REDA can save 70% of gas flow required for RH while generating the same circulation flow rate.

Experimental Research on Reaction Kinetics of Reducing V₂O₅ from Slag by Si and Al

Zhou Yong, Li Zhengbang

2012, 33(1): 65-69.

Abstract(19) PDF(1)

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In order to produce high speed steel with V₂O₅ by direct alloying,reaction kinetic test of reducing V₂O₅ from slag by Si and Al was conducted to study the influence of temperature and slag composition on reduction rate,and reaction mechanism was investigated to identify the limiting factors to reduction rate.Experimental results showed that the diffusion of V₂O₅ in slag to reaction interface was the crucial factor to reduction rate.Through dynamic experimental research,the finally established route of V₂O₅ direct alloying process was: prereduction with silicon and final reduction with aluminum.

Development of HRB500E High Strength Anti-seismic Rebars by Microalloying and Controlled Cooling Process

Su Candong, Chen Wei, Chen Bisheng

2012, 33(1): 70-75.

Abstract(29) PDF(1)

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Considering the existing equipment available in the steelmaking and rolling plants of Honghe Iron and Steel Co.,Ltd.,HRB500E high strength anti-seismic rebars were developed by microalloying,controlled rolling and controlled cooling process and mechanical properties,microstructures,inclusions of rebars so produced were tested by tensile testing machine and metallographic microscopy.The results showed that the rebars exhibited moderate strength ＆ toughness,good anti-seismic performance and low strain aging;Besides,they boosted preferable comprehensive performance,featuring a final temperature after controlled cooling greater than 680 ℃,Mn content less than 1.55%,Nb content less than 0.025%,and core microstructure of ferrite + pearlite +5% bainite.

Research on High Temperature Mechanical Properties of Nb-Ti-V Microalloyed Steel for Ship Plate

Yuan Pengfei, Wu Huajie, Yue Feng, Chen Junjie, Wang Wei

2012, 33(1): 76-81.

Abstract(18) PDF(1)

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High temperature mechanical properties of continuously cast slabs of D36 steel for ship plate were tested by Gleeble-3500 thermomechanical simulator.The morphology of its fracture surface was analyzed by SEM,and its brittleness mechanism was also studied.The results showed that: the brittleness temperature range Ⅰ of the 373# steel slab containing no vanadium was over 1 350 ℃.In the range of 1 350～950 ℃,the slab has a reduction of area over 80% with good high-temperature plasticity.The brittleness temperature range Ⅲ of the specimen was 950～600 ℃ with its reduction of area in the range of 41.7% ~64%.The brittleness temperature range Ⅰ of the 374# steel slab containing vanadium was from melting point to 1 250 ℃,which exhibited good high-temperature plasticity at 1 250～950 ℃.Its brittleness temperature region Ⅲ was 950～600 ℃with reduction of area of 34%~73%.In order to prevent cracking during straightening,the straightening temperature for the slabs should be controlled over 950 ℃.

Research on Friction and Wear Characteristics of 0Cr17Ni7Al Steel

Fang Guanqun, Wang Shuqi, Mao Yishu

2012, 33(1): 82-86.

Abstract(21) PDF(1)

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Friction and wear behavior and mechanism of a type of stainless steel 0Cr17Ni7Al were systematically studied under dry sliding condition with the load range of 25～75 N and the ambient temperature range from 25 ℃ to 400 ℃ by a pin-on-disc high-temperature wear ＆ abrasion tester.The structure,morphology and composition of the worn surface,subsurface and wear debris were examined using XRD,SEM and EDS.The experimental results show that the wear rate tends to increase with the increase of load and ambient temperature.An abrasive wear prevailed at 25 ℃ or under a low load at 200 ℃.With the increase of load,there was a mixed mechanism of adhesive wear and grain wear.An adhesive wear prevailed under a high load at 200 ℃.Fatigue wear occurred as the ambient temperature rose to 400 ℃.The specimen with solution treatment at 1 040 ℃ exhibited the best wear resistance at 25 ℃or under a low load at 200 ℃ while the worst at 400 ℃.

Effect of Grain Composite Electrodeposition on Roughness of Metal Surface

Tan Yong, Liu Changsheng, Yu Xiaozhong

2012, 33(1): 87-90.

Abstract(22) PDF(1)

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In this paper,the intermediate layer prepared with electrodepositing of nickel and super hard particles was then chromed.Parameters,including current density and temperature,were studied in the experiments.Surface roughmeter and SEM were used to obtain the roughness data and micrograph of the surface.The experimental results showed that preferable roughness could be achieved with temperature of 50 ℃,current density of 5 A/dm² and pH of 4.8.From the SEM micrograph,it could be seen that the particles on the surface were uniformly distributed.Difference in electrodepositing time induced different nickel content which affected the binding force.The chromed metal surface showed preferable hardness and roughness（2~4 μm）.

Heat Treatment and Deep Cryogenic Treatment of Hot Die Steel

Qiu Qingzhong, Xiao Feng, Zhang Zhongqiu, Song Jingyan

2012, 33(1): 91-94.

Abstract(24) PDF(1)

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The effects of various heat treatments on hot die steel X20CoCrWMo10-9 were investigated.By analyzing phase structure,microstructure and properties of the steel,optimal quenching temperature of 1 120 ℃ was identified.It was also found that deep cryogenic treatment would improve the hardness and abrasion performance of the steel.After comparison between performances at different tempering temperature and for different length of time,it was concluded the desirable heat treatment process should include the following steps: quenching at 1 120 ℃ plus 8 h deep cryogenic treatment plus 1 h tempering at 650 ℃.

2012, 33(1): 95-96.

Abstract(17) PDF(1)

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2012 Vol. 33, No. 1