共查询到19条相似文献,搜索用时 140 毫秒
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高比例球团矿冶炼是高炉炼铁发展的趋势。由于化学成分、矿物组成和结构的差异,不同企业生产或所用的球团矿还原膨胀的原因各不相同且相对复杂。面向保障矿产资源安全供给的国家重大战略需求,选择白云鄂博铁精矿球团矿作为研究对象,根据球团矿铁氧化物还原理论,从热力学方面深入研究碱度对球团矿还原膨胀性能的影响机理,并结合XRD结果来探究钙结合相在球团矿生产中的变化规律以及对球团矿还原膨胀的影响,找到满足高炉冶炼对球团矿还原膨胀率要求的合理碱度,从而提高白云鄂博铁精矿球团矿在包钢冶炼生产中的比例。完善特殊矿球团矿还原膨胀理论,为复杂共生矿高效冶炼提供理论支撑。研究结果表明,随着碱度的提高,球团矿的膨胀率呈现出先升高后降低的规律,碱度为0.8时,其膨胀率最大,达到75.743%,其外形如同花瓣开花,无法维持原来的球型。综合不同碱度球团矿含铁品位的高低和还原膨胀的大小,得到制备球团矿的最优碱度为1.4。随着碱度的提高,成品球的液相生成量先降低后升高,碱度为0.8时液相生成量最少。球团矿膨胀率先增加是因为球团矿的结晶度提高,晶粒粗大,晶体结构逐渐趋向有序,为铁晶须的生长奠定了基础;膨胀率后减小是因为生成了铁酸... 相似文献
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前言 作者曾于1983年~1985年作为教育部派出的访问学者赴日本研修。在东京大学工学部金属工学科冶金反应工学研究室对包头白云鄂博矿的还原膨胀问题进行了研究。后于1986年7月至10月又赴日本神户制钢所中央技术研究所(现为技术开发本部材料研究所)炼铁研究室继续就“碱金属对球团矿的还原 相似文献
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邬虎林赵殿清边美柱郝志忠罗果萍付国伟黄雅彬曹立刚白晓光吕志义 《中国冶金》2020,30(10):104-104
项目简介:本项目属于钢铁行业炼铁技术领域。本项目通过基础理论及试验研究,取得了在包钢球团工艺配加90%白云鄂博铁精矿生产还原膨胀率控制在20%以内的熔剂性球团矿的技术成果。项目提出生产高镁低硅含氟熔剂性球团矿是实现大幅提高白云鄂博铁精矿在球团工艺配比的最佳技术路线,并提出工业生产熔剂性球团矿的优化配料方案及高炉冶炼熔剂性球团的合理炉料结构。在年产120万t、240万t链篦机 回转窑工艺进行了高镁低硅含氟熔剂性球团矿的生产工业实践,在2 200 m/3高炉进行了配加37%熔剂性球团矿冶炼的工业实践,提高了白云鄂博矿的资源利用价值,为大高炉冶炼含镁熔剂性球团矿提供了宝贵经验,促进了炼铁的绿色化生产,经济和社会效益显著。 相似文献
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为探究球团矿还原过程中产生恶性膨胀的问题,研究了温度对H_2还原Fe_2O_3样条过程中膨胀性能的影响,并采用PCY-G膨胀仪进行在线检测,通过对比不同温度条件下还原产物的外观形貌与显微结构,解释还原反应产生膨胀差异的原因。实验结果表明,H_2还原气氛下,随着还原温度的升高,800℃下样条膨胀最大,样条的最大膨胀量出现先增加后减小的趋势;还原反应达到最大膨胀量所用时间逐渐缩短。随着还原温度的升高,铁相连接更加紧密,样条内外产生更大应力差,致使900℃条件下的还原反应提前进入铁相收缩的状态。 相似文献
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在升温和恒温条件下,采用40%CO—60%N_2混合气体和100%H_2作为还原剂,研究了合成赤铁矿球团矿的还原膨胀特性。对该种球团矿又进行了分阶段控制性还原膨胀试验研究。分析了还原反应动力学条件对膨胀的影响。实验研究证明,用CO—N_2混合气体和用H_2还原多孔合成赤铁矿球团矿,球团矿的膨胀特性有极大差异。我们用局部化学反应造成不同的膨胀模型和产生不同的应力来解释之。 相似文献
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随着稀土选矿技术的日趋进步,白云鄂博稀土精矿的品位提升至65%以上,且可进行大规模的生产应用。以白云鄂博高品位混合型稀土精矿为研究对象,采用XRD、EDS、SEM、AMICS等表征手段对高品位稀土精矿进行系统研究。研究结果表明,高品位精矿中REO品位为67.96%,轻稀土元素占稀土总量的98.65%,属典型富铈低钇型轻稀土,矿中的钙、氟、磷杂质含量明显降低;稀土精矿主要由氟碳铈矿、独居石、萤石、磷灰石构成,稀土主要赋存于氟碳铈矿和独居石,其总质量分数为92.55%;氟碳铈矿和独居石与萤石、铁矿石、硅酸盐、碳酸盐矿物连生,连生关系复杂。高品位稀土矿的特性研究对稀土资源高效综合利用具有一定指导意义。 相似文献
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Xiu-Lan Yu Li Bai Qing-Chun Wang Jia Liu Ming-Yu Chi Zhi-Chang Wang 《Metallurgical and Materials Transactions B》2012,43(3):485-493
The recovery of rare earths, niobium, and thorium from Bayan Obo??s tailings has been investigated because the Bayan Obo ore is rich in rare earths and rich in niobium and thorium, but it is mined mainly as an iron ore and will be used up soon. By carbochlorination between 823?K (550?°C) and 873?K (600?°C) for 2?hours, 76 to 93?pct of rare earths were recovered from the tailings, which were much higher than those from Bayan Obo??s rare earth concentrate, together with 65 to 78?pct of niobium, 72 to 92?pct of thorium, 84 to 91?pct of iron, and 81 to 94?pct of fluorine. This suggests a cooperative reaction mechanism that carbochlorination of iron minerals (and carbonates) in the tailings enhances that of rare earth minerals, which is supported by a thermodynamic analysis. Subsequently, niobium separation from the low-volatile, ultrahigh iron chloride mixture was achieved efficiently by selective oxidation with Fe2O3. This process, combined with the best available technologies for separation of rare earths and thorium from the involatile chloride mixture and for comprehensively using other valuable elements, allows the ore to minimize radioactive waste and to use rare metal resources sustainably in the future. 相似文献
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Studies on the reduction and swelling behaviors of fired pellets, made by mixing hematite iron ore fines of ?100, ?18 + 25, and ?10 + 16 mesh sizes in different proportions, were carried out with low-grade coal in the temperature range of 850–1000°C with an aim to promote the massive utilization of fines in ironmaking. The rate of reduction in all the fired iron ore pellets increased markedly with an increase in temperature up to 1000°C and it was more intense in the first 15-min soak time. Relatively higher reduction rates and swellings/shrinkage were observed in the pellets made by the addition of larger size (+100 mesh) particles in the matrix of ?100 mesh size fines. In general, highest swelling was observed in the fired pellets at a reduction temperature of 850°C, followed by a decrease at 900°C. At both these temperatures, the percentage of swelling increased with reduction time up to the range studied (120 min). The fired pellets reduced at temperatures of 950°C and 1000°C, showed shrinkage, and the extent of this shrinkage increased with increase in exposure time at 950°C. The percentage swelling/shrinkage in the fired pellets was found to be related to their crushing strengths and porosities. 相似文献
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基于莱钢2007年120 m3生产高炉科学解剖研究内容,系统分析了含铁炉料在软熔带位置物化属性。结果表明,高炉软熔带呈不规则倒V形分布,软熔层矿石还原度由低温侧向高温侧逐渐增加,其中烧结矿的还原度由40%~70%增加至80%~95%,球团矿的还原度由40%~50%增加至70%。软熔层低温侧烧结矿金属化率为20%~45%,球团矿的金属化率为10%~20%,在高温侧烧结矿的金属化率为70%~95%,球团矿的金属化率约为50%~70%。含铁炉料在软熔带区域发生了剧烈的还原反应,其中烧结矿金属化率增加的幅度大于球团矿的主要原因为烧结矿的还原性好于球团矿的还原性。矿相分析表明软熔带中球团矿已没有Fe2O3、Fe3O4存在,铁主要以FeO和金属铁存在,在软熔带区域存在被还原生成中空的铁壳球团矿。 相似文献
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含铌铁矿粉氢气选择性还原过程中磷行为 总被引:2,自引:0,他引:2
对白云鄂博含铌铁矿粉氢气选择性还原-熔分-铌铁冶炼的提铌方案中磷的行为进行试验研究。在该试验条件下,磷质量分数为0.100%的含铌铁矿粉通氢气还原后熔分,得到磷质量分数小于0.010%、铌质量分数为2.000%的富铌渣,铁中铌质量分数为0.008%、磷质量分数为0.230%,铌磷分离效果明显,同时熔分后铌品位是原来的3.5倍。试验结果表明,氢气在还原阶段能够在还原铁氧化物的同时将Ca3P2O8还原,通过熔分达到铌与磷、铁元素等分离的目的,铌有效地富集在渣中。 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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分析了气基直接还原竖炉还原段参数的影响因素,找到了各参数的研究方法;在模拟的气基直接还原竖炉还原氛围下进行了铁矿石的直接还原实验,研究了铁矿石的还原性和还原膨胀性;采用颗粒离散元仿真分析软件EDEM对颗粒炉料的传输过程进行仿真分析,研究了炉料的下降运动规律;结合实验数据和仿真结果,确定了竖炉还原段参数的表达式。研究结果表明:铁矿石在模拟条件下的必要还原时间约为3h,且还原膨胀率先增大后减小;竖炉中心炉料的下降速度大于边缘炉料的下降速度,且速度超前比受排料速度的影响较小;从上到下还原段内型曲线由3条拟合线段组成,对应的炉身角分别为:87.162°、88.949°以及90.652°。 相似文献