RH精炼钢水温度预报模型

根据RH精炼过程钢水传热的物理模型,提出了预报RH精炼过程钢水温度的数学模型.根据此模型可以分别计算真空室内和钢包内钢水的温度变化.计算结果表明:在精炼初期2～3 min内,由于炉壁吸热,钢包内钢水温度迅速降低,随后真空室内钢水温度开始回升,4 min后,钢包和真空室内钢水温度趋于均匀.采用该模型预报实际真空脱碳终了温度,其中平均误差在±5 ℃以内的占72 %.     

钢包自开率的影响因素及改善措施

统计分析了LZ20Mn2、20MnV6、20MnTiB等钢种钢水在钢包中停留时间(<135 min～>240 min),出钢温度(<1 640℃～>1 650℃),连铸平台钢水温度(<1 540℃～>1 580℃),钢中Mn含量(<0.5%～>1.3%)对70 t钢包水口自开率的影响。得出随着钢包停留时间延长,出钢温度和连铸平台钢水温度提高,以及钢中Mn含量的增加,钢包自开率可由98.8%降至76.8%。通过加强引流砂用前烘烤,及时清理钢包中残钢残渣,清扫水口,钢水在钢包中平均停留时间由原180 min降至160 min,使钢包自开率由原88.4%上升到97.3%。     

60 t中间包内钢水温度预测模型

根据800炉(300t钢包)样本的多元回归分析,建立了60t中间包内钢水温度-T中间包/℃的预测模型：T中间包=-66.7499+1.03196 T-0.76824x₁-0.00750x₂+0.23253t-0.60624 t²-9.39124×10^-6t³。 式中：T-钢包到达回转台时钢水温度/℃;x₁-钢包浇铸前搁置时间/min;x2-中间包烘烤时间/min;t-钢包钢水浇铸时间/min。对中间包内预测温度统计分析结果表明,中间包钢水预测温度与实测温度之间的误差小于±5℃     

影响钢包自开率的因素分析及改进措施

为提高钢包自开率,分析了引流砂质量、出钢温度、钢水在钢包内停留时间和热修操作对钢包自开率的影响。结果表明,通过调整引流砂的成分配比及粒度分布,严格将水分含量控制在0. 2%以下,出钢温度在1 580～1 620℃、钢水在钢包内停留时间在90 min以内,并进一步加强钢包的日常管理,可使钢包自开率稳定控制在98%以上。     

钢包保温层优化及应用

原复合反射绝热板热导率系数值较大,钢包包壳温度较高,在使用过程中钢水温度损失大;而新型气凝胶绝热板是以纳米材料为主,主要材质为SiO₂气凝胶,具有导热系数低、耐高温、密度小、抗压强度高等优越性能。某钢厂120 t钢包保温层用新型气凝胶绝热板替代原复合反射绝热板的效果表明,钢包包壳表面温度平均下降59～73 ℃;通过两种钢包包壳温度计算得出,在生产中,钢包每周转一次,可节省钢水温损9.88 ℃,钢水温降速率降低0.11 ℃/min;通过实测LF炉软吹结束钢水温度及铸机开浇时钢水温度,钢水温降速率降低0.12～0.13 ℃/min,实际钢水温降速率与钢包包壳节省温度计算的钢水温降速率基本吻合,成本下降2.7元/t(钢),取得了良好的试验效果,为新型气凝胶绝热板在钢厂其他保温设备上的应用提供了重要的参考价值。     

260 t钢包全程加盖工艺实践

为了降低钢水在钢包中的热量损失,鞍钢股份有限公司炼钢总厂260 t钢包采用了全程加盖工艺.实践表明,钢包加盖后,钢包内壁温度提高约320℃;转炉出钢温度和出钢温降分别降低15.5℃和减少2.2℃;LF加热时间和处理周期分别缩短3.1 min和7.6 min,LF白灰加入量减少1.95 kg/t;RH铝氧升温幅度降低4℃/罐以下,减少了夹杂物的生成,提高了钢水质量.     

37Mn5连铸钢水的温降规律

结合37Mn5连续铸钢的生产实践,采用控制容积法,模拟了钢包内钢水温度随时间的变化规律,并应用统计回归和神经网络法预测了钢水从钢包到中间包过程的温降规律,结果表明,现行连铸钢水在中间包内的平均过热度为30℃,高于过热度的最佳值,不利于实现高拉速,高质量,确定连铸钢水从钢包到中间包温降值为25℃;按最佳过热度控制的钢水到达大包回转台时的温度为：第一炉TL＋（51－60）℃,连浇炉TL＋（41－50）℃。     

重钢80t钢包瞬态温度场的模拟研究

通过建立钢包传热数学模型和有限元模拟计算，分析了重钢炼钢厂80t钢包不同烘烤温度、不同绝热层材质对钢水温降的影响，提出了钢水温降速度低于1．5℃/min、的优化方案，模拟结果与现场实测数据基本吻合，为重钢炼钢厂减少钢水温降提供了依据。     

复合反射绝热板在210t钢包上的传热效果

为了考察210 t板坯钢包加绝热板后的保温效果,应用ANSYS商业软件,建立了钢包在盛钢期的传热有限元模型。通过模型计算,得到了加绝热板和未加绝热板2种钢包在静置期间钢水的温降速率,并通过对比同包龄期2种钢包钢壳外部相同位置点温度来考察绝热板的使用效果。试验与有限元模型计算结果表明,绝热板的应用,显著降低了钢包外壁温度(平均温降达77~83℃),并使钢水温降速率减少0.105℃/min。     

钢包钢水保温技术效果对比

降低钢包钢水温降有利于降低冶炼成本、提高铸坯质量。针对敬业钢铁有限公司一炼钢厂80 t转炉出钢后钢包散热快的问题,在80 t小钢包上分别试验了出钢10 min后,钢包纳米绝热板、钢包覆盖剂、钢包加盖以及3种保温技术联合应用时对钢水的保温效果。结果表明:采用纳米绝热板的钢包较普通钢包包壳温度降低26℃;使用SiO_2-Al_2O_3-CaO覆盖剂的钢包钢水温降比使用碳化稻壳覆盖剂少6℃;钢包全程加盖钢水温降比未加盖时少14℃;3种保温技术联合应用时钢水温降较使用碳化稻壳覆盖剂的普通钢包少23℃。钢包保温技术在小钢包上的保温试验取得了满意的效果,促进了企业节能环保工作的开展,同时取得了可观的经济效益。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

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.