CSP结晶器EMBr的冶金效果和流场理论分析

对邯郸钢铁股份有限公司CSP结晶器EMBr冶金效果分析表明,在其它工艺条件相近的条件下,使用EMBr后,薄板坯w(T[O])比未使用EMBr的薄板坯w(T[O])降低了40%,薄板坯中大型夹杂物降低了61%;无电磁制动时,结晶器液面波动为±7 mm,使用电磁制动时,结晶器液面波动为±4 mm,薄板坯内部质量明显改善.应用CFX软件数学模拟了电磁制动及无电磁制动情况下的CSP结晶器流场,模拟结果表明结晶器弯月面钢水中心线速率降低了4倍,湍动能降低了3倍左右.电磁制动可明显提高薄板坯洁净度水平.     

结晶器电磁制动技术的应用研究

论述了板坯连铸结晶器中应用电磁制动技术的发展、研究和应用状况。电磁制动技术可以控制结晶器内钢液面的波动,减少结晶器保护渣的卷渣,有利于结晶器内夹杂物的去除。鞍钢电磁制动的研究结果表明,电磁制动可降低液面波动50%以上,可提高目标拉速0.5m/m in。     

包晶钢Q195方坯连铸结晶器液面波动原因分析与控制

针对某炼钢厂生产的180mm×180mm包晶钢Q195方坯因连铸结晶器液面波动卷渣严重影响产品质量的问题,分析影响结晶器液面波动的因素并且进行多次工业试验,结果表明:钢水[C]质量分数避开0.09%,提高钢水纯净度,使用FGJ-10中包覆盖剂、高氧塞棒,稳定结晶器流场,采用弱冷制度,可以降低结晶器内钢水液面波动量,提高连铸坯质量。采取优化措施后,结晶器钢水液面波动量逐渐恢复到±3mm以内,铸坯降级改判率和废品大幅度下降,缺陷率从3.16%控制到0.65%以下。     

宽度对CSP漏斗形结晶器电磁制动效果影响的数值模拟

 铸坯尺寸是影响电磁制动效果的重要因素。以某钢厂薄板坯CSP漏斗形结晶器为研究对象,建立了描述CSP漏斗形结晶器电磁制动的三维数学模型,研究宽度对电磁制动效果的影响。研究表明：3种铸坯宽度下,电磁制动均可使涡心位置上移并降低下部漩涡范围;电磁制动可降低自由液面水平方向流速,抑制弯月面波动,提高弯月面温度;在结晶器出口处,使用电磁制动可使铸坯宽面坯壳厚度更均匀并提高窄边凝固坯壳厚度;随铸坯宽度增加,电磁制动效果变得不明显。     

电磁制动对CSP结晶器内夹杂物行为的影响

利用数值模拟方法研究了电磁制动对涟钢CSP结晶器内钢水夹杂物行为的影响,并进行了现场验证.数值模拟表明,无电磁制动时,粒径在50 μm以下的夹杂物颗粒其上浮概率几乎为零,200μm夹杂物颗粒上浮概率为6%;有电磁制动时,粒径在50μm以下的夹杂物颗粒的上浮概率为25%,200 μm夹杂物颗粒上浮概率为38%,现场试验表明,采用电磁制动与没有电磁制动相比,铸坯中200～300 μm的大型夹杂物降低了15.9%,300～400μm的大型夹杂物降低了30.2%,大于400μm的夹杂物降低了39.1%.电磁制动数值模拟的结果与现场试验结果有一定的吻合性.     

全幅一段与全幅二段电磁制动对薄板坯连铸结晶器流场的影响

介绍了连铸结晶器流场电磁制动的有限差分数学模型.通过水力学模拟对计算程序首先进行了验证.随后分别计算了实际水口结构条件下全幅一段电磁制动与全幅二段电磁制动的结晶器流场,初步分析了电磁制动工艺对结晶器流场、液面波动的影响.结果表明,通过施加全幅一段电磁制动,能够有效地使结晶器内钢水流速平均化,减小对结晶器窄面凝固壳的撞击,降低液面波动.而全幅二段电磁制动对液面波动的效果更加明显.     

采用薄板坯连铸生产高表面质量冷轧钢板的可行性分析

薄板坯连铸由于拉速高,结晶器容量小,结晶器钢水液面波动高度和表面流速显著高于传统连铸,因此容易造成保护渣卷渣,这是薄板坯连铸生产高表面质量冷轧钢板钢种的主要困难所在。NUCOR、蒂森一克鲁伯等企业采用薄板坯连铸连轧工艺生产冷轧钢板的实践也表明,在表面质量方面与传统工艺产品尚有较大的差距。采用薄板坯连铸工艺生产优质冷轧钢种,应适当增加铸坯厚度,以降低拉速和增加结晶器对钢水流的缓冲作用,可采用120mm厚铸坯(结晶器出口),3m／min左右拉速。为了减少结晶器保护渣卷渣,应对中等厚度薄板坯连铸结晶器内钢水流动控制(SEN结构参数、SEN浸入深度、拉速等)、电磁制动、保护渣等开展深入的试验研究。     

超低碳钢连铸结晶器液面波动原因分析及改进

针对河钢邯钢邯宝板坯连铸机浇注超低碳钢时产生的结晶器液面波动,系统分析了其影响因素。根据液面波动特点,通过提高钢水洁净度、降低钢水过热度、优化浸入式水口插入深度、合理控制中间包吹氩量等措施,连铸可浇性明显改善,超低碳钢结晶器液面波动得到稳定控制,热轧卷翘皮、夹杂缺陷比例由1.38%降低到0.43%。     

邯钢CSP低碳铝镇静钢非金属夹杂物行为研究

通过在炼钢和连铸过程的各个阶段加入不同的示踪元素,采用全氧分析、金相观察、大样电解、电子探针及扫描电镜等多种方法对邯钢CSP流程低碳铝镇静钢中非金属夹杂物行为进行了调查研究,找出了对夹杂物的类型、来源、数量及尺寸大小在不同工序的变化规律,提出了改善薄板坯洁净度的建议。试验结果表明,CSP薄板坯的全氧的质量分数平均为53.3×10-6,与传统工艺连铸坯质量相比还有一定的差距。而非稳定态浇铸对钢水质量的影响非常大,稳态浇铸坯的全氧的质量分数比连浇坯的低22.73%。示踪元素分析表明结晶器保护渣对薄板坯的质量影响最大。     

MCCR产线低碳钢高拉速技术研究与应用

通过统计和分析现场数据,得出限制MCCR薄板坯连铸连轧低碳钢拉速提高的主要因素为结晶器热像图中的冷齿和结晶器液面波动,对冷齿和液面波动的成因进行研究,并提出有效控制措施。研究结果表明,结晶器热像图中的冷齿与结晶器弯月面凝固收缩特性相关,受冷却铜板厚度、碳当量、拉速及保护渣影响,反映到铸坯实物上为凹陷或者裂纹缺陷,需合理匹配形成最优参数组合,以降低因冷齿造成的漏钢风险。当结晶器铜板厚度减薄量在6.7%以内时,一冷水维持原设计流量;当结晶器铜板厚度减薄量在6.8%~11.1%时,拉速4.0 m/min以上时需降低10%的一冷水流量;当结晶器铜板厚度减薄量在11.2%~15.6%时,所有拉速下需降低18%的一冷水流量,同时使用高碱度B型保护渣。针对高拉速下结晶器液面波动问题,通过数值模拟研究浸入式水口插入深度、拉速、结晶器断面宽度及电磁制动等参数对结晶器内流场和温度场的影响规律,得到不同拉速和不同断面条件下电磁制动电流的合理配置,使得拉速达到5.5 m/min时钢液面最大流速仍小于0.3 m/s。上述研究结果应用后,结晶器冷齿问题得到有效缓解,110 mm厚的薄板坯最高拉速达到5.8 m/min,结晶器液面波动控制在±1 mm以内,保护渣液渣层厚度保持在8~10 mm,结晶器热流稳定,实现了高拉速的顺稳生产。     

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.