高炉碱金属富集区域钾、钠加剧焦炭劣化新认识及其量化控制模型

碱金属对高炉内焦炭的破坏大多通过研究碱金属碳酸盐对焦炭气化反应的影响,从而得出钾、钠破坏性相近,在控制碱金属入炉时也基本不对二者进行区分;但高炉调研表明在碱金属富集明显加剧的区域碱金属碳酸盐已分解且焦炭中钾含量均大于钠.本文通过热力学计算得知在碱富集区域碱金属主要以单质蒸气而非碳酸盐或氧化物形式存在,据此设计了模拟此区域有无CO2时钾、钠单质蒸气在焦炭上的自主吸附和破坏实验,结合原子吸收光谱法、X射线衍射法和扫描电镜-能谱分析发现钾蒸气和焦炭中灰分大量结合形成钾霞石后体积膨胀、裂纹扩展导致碱金属富集区域钾在焦炭上的吸附和破坏能力均远大于钠,因此建议尽量采用低灰分焦炭并严格控制入炉钾负荷.进一步研究体系中不同钾蒸气含量对气化反应的影响规律,得出当钾蒸气与焦炭的气固质量比率超过3%后焦炭反应性陡升.依据碱金属富集区域钾、钠在焦炭上的不同吸附和破坏性,建立了钾、钠各自入炉上限及总量上限的量化控制模型.     

论高炉精料

提出高炉精料应考虑铁矿石、焦炭及合理的炉料结构三个方面。对铁矿石精料的要求八字诀是：“高、熟、稳、好、少、净、匀、小”；对焦炭精料要求的四字诀是：“高、低、少、好”。并认为今后应更加重视铁矿石及焦炭的热态冶金性能。     

湘钢高炉锌平衡的研究

分别对湘钢3#、4#高炉取样检测,进行了锌负荷和锌平衡计算,结果表明,高炉中的锌富集主要来自烧结矿,3#,4#(特别是4#)高炉中的锌主要由渣、铁(含除尘灰)排出,这三者的排锌量占总排锌量的92.83%。     

唐钢二炼铁厂使用巴西MBR块矿的生产应用

分析了巴西MBR块矿的矿相结构、矿物组成及冶金性能.MBR块矿的各项冶金性能较好,与烧结矿组成的综合炉料在高炉内的同化过程开始温度和结束温度均较高,但同化速度相对减慢.唐钢二炼铁厂的炼铁生产实践结果表明,适当配用MBR块矿,高炉入炉品位上升,矿耗降低,综合焦比下降,铁成本降低,高炉顺行状态良好.MBR块矿在改善高炉综合技术经济指标的过程中起着重要作用.     

冲天炉过热区热交换机理新探

本文通过模拟研究,得出了冲天炉过热区内对铁水的四种传热方式的传热系数。四种传热方式中,焦炭对铁水的接触传热与辐射传热共占85％左右,焦炭表面燃烧温度的高低对热交换有决定性的影响。焦炭表面温度与炉气温度有较大差别,它主要受焦炭性能影响,是衡量铸造用焦炭质量的一项不可替代的综合性指标。     

Dripping and evolution behavior of primary slag bearing TiO<Subscript>2</Subscript> through the coke packed bed in a blast-furnace hearth

To investigate the flow of primary slag bearing TiO₂ in the cohesive zone of blast furnaces,experiments were carried out based on the laboratory-scale packed bed systems.It is concluded that the initial temperature of slag dripping increases with decreasing FeO content and increasing TiO₂ content.The slag holdup decreases when the FeO content is in the range of 5wt%-10wt%,whereas it increases when the FeO content exceeds 10wt%.Meanwhile,the slag holdup decreases when the TiO₂ content increases from 5wt% to 10wt% but increases when the TiO₂ content exceeds 10wt%.Moreover,slag/coke interface analysis shows that the reaction between FeO and TiO₂ occurs between the slag and the coke.The slag/coke interface is divided into three layers:slag layer,iron-rich layer,and coke layer.TiO₂ in the slag is reduced by carbon,and the generated Ti diffuses into iron.     

高炉喷煤过程中未燃煤粉分析

通过测定邯钢高炉喷吹煤种的燃烧率,分析了邯钢高炉喷煤利用现状.测定了高炉除尘灰中的碳含量,利用岩相测试技术分析了除尘灰中未燃煤粉和焦炭存在的不同结构形态,并确定了高炉除尘灰中含碳物质的来源.结果表明,邯钢高炉除尘灰中的碳元素含量都比较高.炉尘中的未燃煤粉颗粒可分成微变原煤颗粒、气孔原煤颗粒和残碳颗粒;焦炭颗粒可分成类丝碳、粒状镶嵌结构、流动结构、片状结构、块状结构.结合邯钢高炉目前配煤情况,给出了提高邯钢煤粉燃烧率的有效建议,邯钢高炉混合喷吹的首选用煤为长治煤与大湾煤.     

大型高炉布料模型的研究与应用

以无料钟布料过程中物料运动机理为基础,改进了料流轨迹的修正方法,提出了料面形状计算的新方法.高炉布料模型在计算过程中考虑了炉料特性、焦炭塌落等对料面形状的影响,使计算结果更符合实际布料.结合生产实践需求,计算出了各种不同布料制度下炉料的料面形状、炉料径向分布、径向矿焦比等参数,提出了高炉区域焦炭负荷指数,更加直观、形象地对比各种布料制度.利用该模型可解答大型高炉生产上存在的问题,对高炉的实际生产提出了实用性建议,为高炉操作人员调整布料制度提供了理论指导.     

炼焦配煤中添加铁矿石对焦炭性能的影响

通过在炼焦配煤中添加不同配比的加拿大精矿粉、澳大利亚FMG粉和鄂西高磷铁矿粉炼制铁焦,并对其显微强度、相对密度、气孔率、冷强度、反应性、反应后强度和气化反应开始温度进行分析,探讨配煤中添加铁矿石对焦炭性能的影响。结果表明,在配合煤中添加质量分数为15%的加拿大精矿粉所制得的铁焦在反应性高的情况下,具有合适的反应后强度;金属铁对焦炭气化反应具有正催化作用。     

NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> reduction by coupling combustion with recycling flue gas in iron ore sintering process

A new process called ‘NO _x reduction by coupling combustion with recycling flue gas (RCCRF)’ was proposed to decrease NO _x emission during the iron ore sintering process. The simulation test of NO _x reduction was performed over sintered ore and in the process of coke combustion. Experimentally, NO _x reduction was also carried out by sintering pot test. For sintered ore, the amount of NO _x emission is reduced by 15wt%–25wt% at 400–550°C using 2.0vol% H₂ or 2.0vol% CO, or reduced by 10wt%–30wt% at 560–720°C using 0.15vol% NH₃. NO _x reduction is around 10wt% by coupling combustion of pyrolysis gas and coke, or around 16wt% by recycling flue gas into coke combustion. By RCCRF, the maximum NO _x reduction ratio is about 23wt% in coke combustion experiment and over 40wt% in sintering pot test.     

煤粉-菱镁石混合喷吹对安钢高炉操作的影响

对安钢7号高炉的造渣制度进行了分析,提出从风口添加含MgO物料是改善炉渣性能的有效途径.在安钢7号高炉进行了添加轻烧菱镁石的煤粉喷吹工业试验.结果表明:风口喷煤中添加轻烧菱镁石可以有效地解决w(Al2O3)升高对炉渣冶金性能和高炉冶炼的影响,有利于优化高炉生产指标.对安钢7号高炉,煤粉中添加轻烧菱镁石的适宜比例为3%;炉渣中w(MgO)/w(Al2O3)为0.60～0.65时,高炉铁水物理热明显改善、硫的分配系数有所提高.在实施混合喷吹措施时,应适当调整高炉的热制度、造渣制度、焦炭负荷,控制适宜的高炉"炉缸煤气热量的平衡点"等参数.     

K2CO3 catalysis on the reactivity of top charged coke and stamp charged coke

The catalysis of K₂CO₃ on the reactivity of top charged coke and stamp charged coke from Pansteel in China was studied. The coke reaction index of the stamp charged coke was 1%–2% higher than that of the top charged coke. Under the catalysis of K₂CO₃, the coke reaction index of both cokes approximately increased by 4%, 6%, 10% and 6% at 900, 1000, 1100 and 1200°C, respectively. The reactivity of the K-enriched stamp charged coke was 1%–2% higher than that of the K-enriched top charged coke below 1100°C. However, only negligible differences were found in the temperature zone between 1100 and 1200°C. Scanning electron microscopy images illustrated that pores in the top charged coke were smaller and equally distributed, while relatively more big pores exist non-homogenously in stamp charged coke. Due to the different processes in production, the stamp charged coke was more porous and most of the pores tended to be applanate. Cracks were observed in the microstructure of the stamp charged coke during the carbon solution reaction, implying the inferior quality of the stamp charged coke to the top charged coke at high temperature. Diffusion of K during the carbon solution reaction was studied by the energy dispersive spectrometry. It is found that K gradually spreads into the center of lumpy coke with the rising of temperature and is equally distributed on the edges of pores at 1200°C. Besides, oxidation reactions of functional groups become faster with the catalysis of K.content     

Effect of CO<Subscript>2</Subscript> and H<Subscript>2</Subscript>O on gasification dissolution and deep reaction of coke

To more comprehensively analyze the effect of CO₂ and H₂O on the gasification dissolution reaction and deep reaction of coke, the reactions of coke with CO₂ and H₂O using high temperature gas-solid reaction apparatus over the range of 950-1250℃ were studied, and the thermodynamic and kinetic analyses were also performed. The results show that the average reaction rate of coke with H₂O is about 1.3-6.5 times that with CO₂ in the experimental temperature range. At the same temperature, the endothermic effect of coke with H₂O is less than that with CO₂. As the pressure increases, the gasification dissolution reaction of coke shifts to the high-temperature zone. The use of hydrogen-rich fuels is conducive to decreasing the energy consumed inside the blast furnace, and a corresponding high-pressure operation will help to suppress the gasification dissolution reaction of coke and reduce its deterioration. The interfacial chemical reaction is the main rate-limiting step over the experimental temperature range. The activation energies of the reaction of coke with CO₂ and H₂O are 169.23 kJ·mol-1 and 87.13 kJ·mol-1, respectively. Additionally, water vapor is more likely to diffuse into the coke interior at a lower temperature and thus aggravates the deterioration of coke in the middle upper part of blast furnace.     

微波强化铁屑─焦炭处理活性艳红X-3B废水

以活性艳红X-3B为主要对象，在传统的内电解处理法的基础上，利用微波使铁炭床再生，强化处理染料废水，并初步探讨铁炭内电解和微波强化的作用机理。实验结果表明，在铁炭体积比为4：3，铁屑粒径为2-4mm，染液pH为5，反应时间为90min时，处理染料浓度为0．75g／L的染液，CODCr的去除率可达80％以上，脱色率也达99％。在最佳反应条件下研究微波对铁炭床的强化作用，结果显示原始的铁炭床可以重复使用4次以上，当处理效果有明显下降时，利用微波再生铁炭床2min，处理效果恢复，且还可继续使用两次，再次再生，铁炭仍有一定的处理效果。微波不仅加强了铁炭床的处理效果，还延长了铁炭床的使用周期。     

NOx reduction in the sintering process

A new process, NO_x reduction with recycling flue gas and modifying coke breeze, was proposed. The effects of modified coke breeze and recycled flue gas on NO_x reduction were investigated by sinter pot tests. The results show that the NO_x reduction rate is over 10wt% in the sintering of modified coke breeze, the effects of the additives on NO_x reduction are: CeO₂>CaO>K₂CO₃. The NO_x reduction rate increases with the amount of recycled flue gas, and is 22.35wt% in the sintering with recycling 30vol% of the flue gas. When 30vol% of the flue gas is recycled into the sintering of CeO₂, CaO, and K₂CO₃ modified coke breeze, the NO_x reduction rates are 36.10wt%, 32.56wt%, and 32.17wt%, respectively.     

烷烃油滴在超临界二氧化碳中溶解的分子动力学模拟

采用分子动力学模拟方法研究5种正构烷烃油滴在超临界CO2(sc CO2)中的溶解过程及其微观作用机制。结果表明:烷烃在sc CO2中的溶解能力随其链长的增加而逐渐降低。链长小于18时,烷烃易溶于sc CO2;链长大于18时,sc CO2对烷烃的溶解能力较弱。色散作用在sc CO2溶解烷烃的过程中起主要作用。色散作用随烷烃链长的增加而减弱,其强弱导致了不同链长的烷烃在sc CO2中的溶解能力不同。短链烷烃分子与CO2接触的概率较大,同时烷烃分子在sc CO2中的伸展程度随其链长的增加而减弱,导致烷烃与CO2间色散作用强弱不同。     

拓扑结构在钢铁企业发电节点网络的应用

以钢铁企业电力能源管理为背景,应用拓扑学知识建立了钢铁企业的分布式发电节点网络结构,给出了网络拓扑结构的评价体系,提出了网络结构的优化原则.分析表明,节点(指干熄焦发电、燃气蒸汽联合循环发电机组(CCPP)、高炉)之间和各自设备蒸汽管道、煤气管道的距离越短越好,干熄焦设备、CCPP、高炉设备的地理位置应在一条直线上.依据优化原则得出最适合钢铁企业的6种发电节点网络的拓扑结构,实现了结构空间上的优化,进而为企业降低了能源消耗,减少了电力经济成本.     

未燃烧煤粉对焦炭粉化性能的影响

为了弄清楚高炉内未燃烧煤粉（简称ＵＰＣ）对焦炭性能的影响，我们在实验炉内做了纯焦炭恒温处理，气化反应以及焦炭层喷吹ＵＰＣ后气反应一小时后焦炭样的粉化情况，得出的主要结；（ａ）同一温度条件下，纯焦炭气化反应一小时粉化最严重，而焦炭层喷吹ＵＰＣ后粉化程降低；（ｂ）同一温度条件下，随着焦炭层喷吹ＵＰＣ量的增加，气化反应后焦炭的强度提高，粉末量减少。     

轧辊用合金白口铸铁显微组织对热疲劳抗力的影响

研究了轧辊用合金白口铸铁的几种材质中不同碳化物形态和不同基体组织对热疲劳抗力的影响,找出了热疲劳裂纹的主要萌生源地和扩展通道,确认了在碳化物和基体中M23C6和奥氏体的热疲劳抗力最佳。     

重点钢铁厂铁矿石还原及焦炭气化的藕合反应

通过在模拟高炉温度和煤气成分变化的条下,对我国重点钢铁厂铁矿石还原及焦炭气化的藕合反应研究,阐明了焦炭气化与铁矿石还原与反应历程有关。分析预测高炉冶炼效果除考虑恒定温度和恒定煤气成分下焦炭与铁矿石冶金性能外,还应考虑焦炭与铁矿石藕合反应过程CO过剩量。研究表明宝钢、首钢、本钢、鞍钢CO过剩系数ηc较小,煤气利用好;包钢、重钢和梅山冶金公司ηco较大,煤气利用较差。