共查询到19条相似文献,搜索用时 78 毫秒
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以炼铁厂常用烧结矿、球团矿以及块矿为研究对象,考察了不同含铁原料在高炉炼铁工艺和COREX非高 炉炼铁工艺2种煤气条件下的低温还原粉化行为。研究结果表明:①铁矿石的结构组成决定了其粉化形式,块矿 和烧结矿的粉化形式均表现为“裂开式”,粉化产生的细小粒级颗粒较均匀地分布于-6.3 mm范围;不同于烧结矿 和块矿,球团矿则属于“剥落式”粉化,粉化产物粒径主要集中在-0.5 mm范围;②在还原气氛和温度相同的情况 下,烧结矿粉化程度最高,球团矿次之,块矿最低;③还原温度对3种含铁炉料的还原粉化程度均具有重要影响,当 还原煤气条件相同时,3种含铁炉料的低温还原粉化指数均在550℃时达到最大值;④COREX炼铁工艺的煤气条 件加剧试验用铁矿石的低温还原粉化程度,但对不同类型铁矿石的影响有所差异,综合粉化产生的细小颗粒的增 幅可知,块矿受其影响程度较大,其次是球团矿,而烧结矿对煤气性质改变的敏感性最小。 相似文献
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铁矿石烧结矿低温还原粉化理研究 总被引:3,自引:1,他引:2
介绍了无填料环氧树脂浇注干式变压器计算机辅助优化设计软件的特点,给出了数学模型、程序结构和框图,并用计算实例证实了该软件的实用性。 相似文献
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铁矿石烧结矿低温还原粉化机理研究 总被引:4,自引:0,他引:4
铁矿石烧结矿低温还原粉化机理研究[澳大利亚]C.E.LooN.J.Bristow关键词烧结矿,低温还原粉化,机理普遍认为,含铁原料在高炉上部的物理粉化对高炉操作及其稳定性有显著影响,60年代引入“低温还原粉化”这一术语来说明这种现象。一般,用来检测含... 相似文献
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烧结矿低温还原粉化的研究 总被引:6,自引:0,他引:6
本文阐明了烧结工艺条件、烧结矿微观组织结构与烧结矿低温还原粉化的内在联系和规律。对烧结矿低温还原粉化行为及氧化亚铁的影响,提出了一些新观点。这些观点对指导我国造块工业生产具有重要意义。 相似文献
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铁矿石烧结矿低温还原粉化机理研究(续)[澳大利亚]C.E.LooN.J.Bristow关键词烧结矿,低温还原粉化,机理3结果及讨论所提出的模型认为当裂纹延伸至十分坚韧的矿相时,由于裂纹顶端的能量或应力强度不足以使其穿过该相扩展,因而裂纹被截断或其扩展... 相似文献
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赵伯辉 《金属材料与冶金工程》1998,(2):9-11
介绍了湘潭钢采用工业废湘与一定浓度的CaCl2溶液配制喷洒在烧结矿的表面上,通过控制喷洒液的浓度以及吨烧结矿的喷洒量,实现了烧结矿RDI值平均降低56.7%,使高炉产量提高10.50%,降低焦比35.5%kg/t。 相似文献
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本文分析了我司试验和生产应用“烧结矿低温学原粉化控制技术”的情况。通过调试摸索和工业试验表明:此技术工艺简单,操作方便,效果明显,有用后,烧结矿低温还原粉化率可降低约50%,高炉料柱透气性改善,煤气利用率提高,高炉实际节焦6.85kg/t,增产6.02%。 相似文献
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The reduction degradation characteristics of typical sinter, pellet and lump ore were tested with the reducing gas conditions simulating two kinds of iron-making processes. The results show that, in the same condition of gas composition and temperature, the reduction degradation degree (RDI<3.15 mm) of sinter is high, RDI<3.15 mm of lump ore is low and RDI<3.15 mm of pellet is in the middle level. With two kinds of gas composition simulating different iron-making processes, the reduction degradation indices (RDI) of three kinds of iron ores all present the tendency of “inverted V-shape” in the temperature range from 450 to 650 ℃, and the RDI reach the maximum value at 550 ℃. The reduction degradation degrees of iron ores are extended when mixing the gas with hydrogen to increase the reduction potential, and the influence extent is discrepant for different iron ores. Colligating the increase amplitude of grains in small size fraction, the influence of reducing gas on lump ore is the greatest, the influence on sinter is the second, and the sensitivity of pellet on the reducing gas properties change is relatively small. As for the degradation form, lump ore and sinter both present the degradation of cracking, and the distribution of small grains generated from the cracking is in the range from 0.5 to 6.3 mm uniformly. The lump ore presents surface cracking, while sinter presents integral cracking. The pellet presents the degradation of surface stripping, and the proportion of grains smaller than 0.5 mm is the highest, which is up to 90% in the grains smaller than 3.15 mm. 相似文献
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提出了基于低温快速预还原的熔融还原炼铁流程。由三部分组成:熔融气化炉,主要功能是熔化海绵铁和产生预还原所需的还原煤气;预还原部分,由两级快速循环床和一级矿粉预热床组成,主要功能是将矿粉转变成高金属化率的铁粉,金属化率大于85%;煤气处理,包括尾气换热、煤气洗涤、煤气增压、脱除CO2等工序,功能是调节预还原所需的煤气成分、煤气量与温度。新工艺采用精矿粉或粒度小于1 mm的矿粉,具有还原温度低、反应接近平衡态、金属化率高等特点,吨铁燃料比有望在600 kg左右,实现炼铁工艺的高效、节能与减排。 相似文献
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Mithilesh Kumar Himanshu Baghel 《Mineral Processing and Extractive Metallurgy Review》2013,34(4):249-267
In the present investigation, the reduction and swelling behaviors (in low grade coal) of fired iron ore pellets, prepared by blending hematite iron ore fines of ?100, ?18 + 25, and ?10 + 16 mesh sizes in different proportions, have been studied in the temperature range of 850–1000°C with an objective to promote massive utilization of fines in sponge ironmaking. An increase in temperature up to the range studied (850–1000°C) substantially enhanced the reduction rate and the rate was found to be highest in the first 15–30 min at all these temperatures. All the fired pellets, made by mixing iron ore particles of ± 100 mesh size, have shown approximately the same reduction rates and slightly higher swelling indices than those made from fines of ?100 mesh size only. In all the fired pellets reduced at temperatures of 850°C and 900°C, the results indicated an increase in the extent of swelling with reduction time. Reduction of fired pellets at temperatures of 950°C and 1000°C exhibited shrinkage in their reduced products, and the extent of this shrinkage increased with increase in exposure time. 相似文献
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Ironorecoalmixedpelletsarecapableofquicklyself reduction .Intheyearsofsixties ,theInmetcoprocessandMidrexFastmetprocessformakingcoalmixedpelletstodealwiththesecondarydustinironandsteelplantortoproduceDRI[1- 3] weredevel oped .Recently ,alotofbasicresearcheso… 相似文献
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国内某厂生产的低钛烧结矿可用于2 500 m3高炉冶炼,强度指标达到普通烧结矿水平,但其低温还原粉化率仍比普通烧结矿高40%以上,还原粉化机理尚不明确。通过分段测试低钛烧结矿的还原粉化率并进行矿相分析,结果发现:低钛烧结矿中的赤铁矿-气孔结构是产生裂纹的源头,铁酸钙熔蚀结构是主要粘结相,但此结构中有许多细小裂纹,裂纹沿程存在许多赤铁矿晶粒,其还原速率较快且易形成交叉网状裂纹,使粘结相结构受到严重破坏,致使烧结矿还原粉化性能差。 相似文献
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用XRD、SEM和化学分析等方法对2种回转窑工艺还原低品位软锰矿的产物进行表征,同时结合硫酸浸出试验,考察锰、铁和铝的浸出差异。结果表明:改进回转窑工艺的产品中锰的还原率可达到93%以上,原回转窑工艺锰的还原率为50%~90%。常温常压时在较佳浸出条件下,酸矿比0.55∶1、液固比5∶1、时间40 min、搅拌速度300 r/min,改进回转窑工艺使锰的浸出率达94.1%,高于原回转窑工艺的产品,而铁、铝的浸出率则相对较低,分别是33.6%和26.3%。将回转窑中的燃烧室和还原室分离有利于提高锰的还原率,改进回转窑工艺产品中锰、铁、铝的存在形态,而颗粒表面粗糙、带小孔有裂纹的形貌具有较大比表面积,有利于提高锰的浸出率。 相似文献