不锈钢AOD渣粉尘控制及其工程性能

 不锈钢AOD渣在冷却过程中由于晶格转变体积膨胀导致粉化,易造成粉尘污染。研究表明,出渣时喷入含硼改质剂能有效抑制AOD渣从β-C2S相向γ-C2S相的晶格转变,从而使粉化扬尘率降低90.1%。对无害化处理后的不锈钢AOD渣进行资源化利用探讨,结果显示,由于钢渣具有水硬胶凝活性,可作为水泥砂浆掺合料取代部分水泥,掺量范围应在0～30%之间。同时,对AOD渣及其水泥试块进行毒性浸出检测,结果表明,其中总铬、六价铬等浸出值均低于标准限值,不存在重金属浸出的问题,可进行后续资源化利用。     

不锈钢AOD渣固化效果影响因素及其机理

 不锈钢氩氧脱碳（AOD）渣在冷却过程中易发生体积膨胀导致粉化扬尘,这不仅会对环境造成严重污染,给人体带来很大危害,还会造成资源的浪费,因此急需解决不锈钢渣的粉化扬尘问题,提高不锈钢渣的利用率。对不同改性剂对渣的粉化抑制效果进行研究,结果表明,随着B2O3和P2O5掺量的增加,对AOD渣有明显的固化效果,随着CuO的增加,AOD渣没有明显固化。分析原因表明,通过向不锈钢渣中添加半径比Si4+小的离子如B3+、P5+,可以使其在2CaO·SiO2的晶界或位错上富集,降低缺陷的自由能,降低[γ-2CaO·SiO2]成核的驱动力,抑制[γ-2CaO·SiO2]晶核的形成及长大,使2CaO·SiO2可以更好地稳定在[β]相,从而抑制了不锈钢渣的粉化扬尘。     

不锈钢风淬渣非平衡凝固晶相偏离评价

不锈钢渣的风淬法处理是一种快速的非平衡冷却凝固过程。为了探究不锈钢风淬渣的结晶行为,通过Factsage计算钢渣平衡凝固过程,利用X射线衍射法分析AOD炉不锈钢风淬渣的主要矿物组成,采用扫描电子显微镜观察了其各自的微观形貌和分布。结果表明,随着钢渣颗粒粒径由大于4 mm减小到大于0.5 mm,结晶物相面积占比由36.28%降低到24.88%。同时,快速冷却会使平衡态下不稳定的Ca₃SiO₅分解受到抑制而使其保留下来。此外快速冷却会抑制晶体形核、生长,影响结晶度,玻璃体比例增大进而提高炉渣胶凝活性。通过控制风淬时气体流速(冷却速度)可以控制钢渣物相组成,改变钢渣的胶凝活性,改善钢渣的利用率。     

济钢转炉钢渣热闷技术的开发应用

为解决钢渣喷水冷却存在的扬尘大、污染严重、粉碎难等问题,设计开发了利用钢渣余热的闷渣技术。依据产渣量设计了闷渣坑个数、装渣量、闷渣时间等闷渣基本参数,通过对转炉渣冷却时间、闷渣水压力和闷渣水流量的探索与优化,实现了全部钢渣的粉化。     

转炉钢渣热焖技术的开发应用

为解决钢渣喷水冷却存在的扬尘污染严重、粉碎难等问题,设计开发了利用钢渣余热的焖渣技术。依据产渣量设计了焖渣坑个数、装渣量、焖渣时间等基本参数。通过对转炉渣冷却时间、焖渣水压力和焖渣水流量等工艺参数的探索与优化,实现了全部钢渣的粉化。     

炼钢渣中的碳溶解度

通常碳素钢是通过BOF转炉以及真空脱气设备脱碳。众所周知 ,通过转炉脱碳 ,碳含量只能降低到0 0 1%～ 0 0 3% ;通过真空处理 ,碳含量只能降低到 2 0 ppm (2 0× 10 - 6 )。不锈钢由于碳与铬的亲合力更强而导致脱碳比碳素钢更难。不锈钢炼钢过程中容易产生增碳 ,AOD转炉中吹氧后不锈钢钢水中的碳含量在随后的精炼过程中将增加。研究认为碳含量的增加是由于渣中的碳或合金中的碳造成的。文中回顾了工业AOD渣中的碳含量 ,为了阐明增碳现象 ,测量了CaO基钢渣中的碳溶解度。碳含量随CaO活度的增加而增加。渣中碳溶解的机理可用CO2 气相与…     

淋溶气氛对AOD不锈钢渣中铬动态淋溶的影响

AOD不锈钢渣(AOD渣)中的铬主要以三价态存在,但是在一定的条件下会被氧化从而以六价态释放至环境中造成生态破坏.以AOD渣为研究对象,采用长期动态淋溶的试验方法,研究了淋溶气氛对AOD渣中铬动态淋溶特性的影响.结果表明,淋溶气氛对浸出液氧化还原电位影响较为显著,空气气氛下氧化还原电位值在淋溶20 d之后明显高于氮气气...     

400系易切削不锈钢硫铁加入方式优化

邢钢一步法(脱磷站+60t AOD+60t LF)生产400系易切削不锈钢过程中,前期采用硫铁全部在AOD出钢时加入配[S],AOD出钢至上机浇铸过程中钢渣碱度始终处于低碱度范围(R=1.40～1.95),硫铁消耗较大,钢液氧含量偏高,随着冶炼炉数的增加,炉衬侵蚀严重,影响AOD炉龄和钢坯质量,且钢渣较长时间处于低碱度状态,极易造成钢中[C]含量的上升(尤其是430F、430FR低碳类钢种),很难实现多炉连浇。后期通过优化硫铁加入方式,在LF后期加硫铁,AOD炉渣碱度2.0～2.3,LF炉渣碱度1.6～2.0,缩短低碱度渣处理时间,降低[S]损耗和钢液氧含量及对炉衬侵蚀。使易切削不锈钢[S]的收得率由62%提高到75%,吨钢硫铁消耗下降2.12 kg,铸坯皮下气泡等缺陷得到控制。     

滚筒法不锈钢钢渣处理技术的研究和应用

不锈钢钢渣的环保化处理是钢铁行业面临的难题之一,不锈钢钢渣中高含量游离CaO与MgO导致浸泡处理时粉化严重,环境污染大;不锈钢钢渣中不稳定的六价铬易溶于水造成水体污染。通过对滚筒法处理不锈钢钢渣的工艺抑制不锈钢钢渣粉化和抑制Cr3+的氧化析出进行研究和机理分析,并结合工程实例应用,论证了采用滚筒法处理不锈钢钢渣的可行性,为不锈钢钢渣环保化处理和资源利用奠定了基础。     

S系易切削Cr-Ni奥氏体不锈钢精炼工艺的优化和应用

S系易切削奥氏体不锈钢303CuS2(%:≤0.08C、8.00～10.00Ni、17.00～19.00Cr、1.50～3.50Cu、0.24～0.35S)冶炼的工艺为60 t EAF-60 t AOD-60 t LF-CC流程。通过将AOD精炼渣的碱度由原先的2.0降至1.6和控制AOD出钢渣量,AOD出钢的[S]由0.004%～0.006%提高到0.008%～0.010%,并通过喂含S量50%的S线,控制终点温度,使S的回收率由原先的30%～50%提高到60%～70%,产品合格率由85%提高到100%。     

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.