Reaction of FeO-V2O5 System at High Temperature

 FeO and V2O5 are two main components of the obtained vanadium steel slag, and the reaction of FeO-V2O5 system determines the physical property of the slag. Through thermodynamic calculation and experimental study, it can be found that within the ranges of steel-making temperature, V2O5 is reduced to VO2. As FeO exists in FeO-V2O5 system, VO2 will be reduced to V2O3 further while FeO is oxidized to Fe2O3. In this multi-system, as the content of FeO and temperature increase, the system will have products in turn such as V3O5, V3O4, FeVO4, Fe2VO4 and Fe3O4. The products are mainly V3O5 and Fe2O3 when the content of FeO is 0.58 mol and the temperature is 1100 K, and as the temperature increases, Fe2O3 starts to react with V2O5 and then generates FeVO4; FeVO4 disappears while the content of FeO and the temperature increase at the same time, and then Fe2VO4 is generated by the reaction of FeO, Fe2O3 and V2O3. Iron oxides are also generated such as Fe3O4 and so on.     

黑钨矿与碳酸钙人工合成白钨的反应过程和机理

研究了黑钨矿与碳酸钙煅烧合成白钨的反应过程和机理。实验结果表明:在550℃下煅烧黑钨矿时开始出现白钨相;在800℃下黑钨矿与碳酸钙能完全合成为白钨,主要产物为CaWO4、Fe2O3、Mn2O3。在有空气存在的条件下合成白钨的反应分两步进行:第一步生成CaWO4、FeO、MnO,第二步FeO、MnO氧化生成Fe2O3、Mn2O3。     

低碳钢表面FeO层空气条件下等温转变行为的研究

采用热模拟试验机研究了不同温度和等温时间条件下低碳钢表面形成的FeO层的等温转变行为。试验结果发现,在600℃时,FeO只发生先共析反应而无共析反应发生。在650℃时,无任何析出反应发生。FeO层的等温转变遵循着"C"曲线规律,450~550℃为FeO分解反应的"鼻尖"温度范围。FeO的等温转变分为两个阶段,即析出先共析Fe3O4的第一阶段和后续发生的共析反应(FeO→Fe+Fe3O4)阶段。在350℃时形成的共析反应产物的片间距最小。通过热力学分析和FeO层中氧的贫化与富集分别解释了FeO的先共析和共析反应行为。     

从钒浸出液中沉淀结晶型钒酸铁试验研究

研究了常压下向钒浸出液中加入硫酸铁沉淀结晶型Fe4(VO4)4.5H2O,考察了温度、pH和添加剂C对沉淀产物钒酸铁的影响。对沉淀产物进行X-射线衍射(XRD)分析和电子扫描电镜观察,结果表明:沉淀产物的n(V)/n(Fe)和钒沉淀率随pH和温度的升高而下降;加入添加剂C有利于钒酸铁的结晶,同时提高产物的n(V)/n(Fe)和钒沉淀率;最佳沉淀条件为:pH为2~3,反应温度90℃,反应时间72 h,加入添加剂C,此条件下,沉淀产物为Fe4(VO4)4.5H2O,n(V)/n(Fe)接近于1,粒度尺寸主要分布在5~15μm范围内,钒沉淀率在97%以上,。     

FeO-V2O5二元相图的研究

对FeOV2O5二元系通过XRD试验进行物相分析,理论计算中间化合物的热力学参数,并建立了溶液热力学模型,结合FACT软件计算绘制出FeO-V2O5二元系相图,通过DSC试验和XRD试验验证相图.此体系相图由三个共晶反应组成并且生成两种中间化合物反式尖晶石Fe2VO4和钒酸铁FeVO4,试验的结果对理论计算出的相图有很...     

CO还原Fe2O3过程中金属铁析出的微观行为

 通过原位观察和同步热分析的方式,研究气固两相界面还原反应时金属铁析出形态、矿相结构演变过程,明确金属铁的析出形态与显微结构、黏结特性之间的关系。结果表明,CO气氛下Fe2O3还原时金属铁主要以纤维状生成的铁晶须为主,还原速率是决定这种形态差异的主要原因;在Fe2O3→Fe3O4→FeO中只会因晶格转变产生体积大小变化,且伴有裂纹和孔洞的发生,没有铁晶须生成;在FeO→Fe中出现铁晶须形核和生长,且铁晶须是100%的纯金属铁。要避免铁晶须生成,就要在FeO→Fe转变时抑制铁原子的定向迁移。     

CSP流程薄板坯及热轧板卷氧化皮组织演变

 采用SEM和XRD方法对CSP冷轧冲压用钢薄板坯和热轧板氧化皮进行了研究。结果表明：覆盖在板坯表面的氧化皮对氧化性炉气的高温腐蚀有明显保护作用,均热前后Fe2O3:Fe3O4:FeO为5:35:60,新鲜基体腐蚀严重些,Fe2O3和Fe3O4含量增加到28%和64%;卷取后快冷钢的氧化皮以2层结构为主,Fe2O3:Fe3O4:FeO为6:31:63,缓冷钢的氧化皮中析出了弥散或薄片状的Fe相,Fe2O3:Fe3O4:FeO:Fe为8:73:15:4,二者厚度相差不大;卷取温度升高,快冷钢的Fe2O3和Fe3O4的含量略有降低,但缓冷钢中残余FeO含量明显减少,不利于酸洗。     

低温非平衡条件下氧化铁还原顺序研究

研究了低温条件下(＜570℃)CO和H2还原氧化铁的动力学机理.结果表明:实际还原过程属于非平衡态过程,它的还原机理与还原气体的成分相关.当还原气体中CO(或H2)的含量不能满足Fe3O4 CO(H2)→3FeO CO2(H2O)反应进行的要求时,氧化铁的还原顺序为Fe2O3→Fe3O4→Fe;如果还原气体成分满足此要求,Fe2O3→Fe3O4→Fe和Fe2O3→Fe3O4→FeO→Fe两种还原顺序将同时存在.     

钛铁矿磁化焙烧分离的热力学分析

为了探讨钛铁矿以Fe3O4和TiO2分离路线的可能性,对钛铁矿低温下的氧化与还原热力学进行了分析研究.结果表明:若通过直接磁化焙烧的方法,氧气能够将FeTiO3氧化成Fe3O4,但实际操作会难于控制反应条件,易过氧化成Fe2O3和Fe2TiO5;使用CO2和H2O气体将FeTiO3氧化生成Fe2O3和Fe2TiO5的反应更容易发生,而非生成Fe3O4,因此这两种气体也无法直接将钛铁矿磁化;若通过间接磁化焙烧的方法,先用氧气或空气将FeTiO3氧化,而后无需较高浓度的CO以及较低的温度即可以将FeO3和Fe2TiO5还原成Fe3O4.根据上述结果,提出钛铁矿分离钛与铁的新路线:将钛铁矿通过氧化和磁化,再通过磁选的方式得到铁精矿粉和钛渣.     

钒钛铁精矿内配碳球团高温快速直接还原历程

采用高温实验炉,在1 350℃,氮气保护气氛条件下对钒钛磁铁精矿内配碳球团进行了阶段还原试验,通过TG-DSC、XRD、SEM等检测方法对不同时间内配碳球团还原的组织成分、显微结构等进行研究.结果表明,钒钛铁精矿的还原历程依次为Fe2TiO4和Fe3O4、3(Fe3O4)·Fe2TiO4、Fe3O4·Fe2TiO4、Fe2TiO4和FeO、Fe和FeTi2O5;在磁铁矿大量还原生成浮士体的阶段,钛铁矿与新生成的浮士体发生"钛铁晶石化",最终还原转变为单质铁和含铁黑钛石.     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.