Application of Air-cooled Blast Furnace Slag Aggregates as Replacement of Natural Aggregates in Cement-based Materials：A Study on Water Absorption Property

The influence of air-cooled blast furnace slag aggregates as replacement of natural aggregates on the water absorption of concrete and mortar was studied, and the mechanism was analyzed. The interface between aggregate and matrix in concrete was analyzed by using a micro-hardness tester, a laser confocal microscope and a scanning electron microscope with backscattered electron image mode. The pore structure of mortar matrixes under different curing conditions was investigated by mercury intrusion porosimetry. The results showed that when natural aggregates were replaced with air-cooled blast furnace slag aggregates in mortar or concrete, the content of the capillary pore in the mortar matrix was reduced and the interfacial structure between aggregate and matrix was improved, resulting in the lower water absorption of mortar or concrete. Compared to the concrete made with crushed limestone and natural river sand, the initial absorption coefficient, the secondary absorption coefficient and the water absorption capacity through the surface for 7 d of the concrete made from crushed air-cooled blast furnace slag and air-cooled blast furnace slag sand were reduced by 48.9%, 52.8%, and 46.5%, respectively.

Environmental-friendly Ramming Materials for Mud Package and Taphole of Large-scaled Blast Furnaces

The compositions, structures and properties of envi- ronmental-friendly ramming materials for mud package and taphole of large-scaled blast furnaces were studied. The results show that the formation of silica fibers makes structure of ramming materials dense. During the process of extruding mud and ramming materials, SiC is partly oxidized ; CaO , F% 03 and carbon penetrate towards the outer wall. The improvement of ramming materials can inhibit the penetration of molten slag, iron and carbon. The bulk density of environmental-friendly ramming ma- terials dried at 200 ℃ is 2.90 g · cm-3, the cold com- pressive strength of this kind of ramming materials dried at 200 ℃ is about 17. 0 MPa and fired at I 450 ℃ is about 39. 2 MPa.

Refractory Gunning Material for Inner Lining Maintenance of Blast Furnace

YB/T 4194-2009 1 ScopeThis standard specifies the term and definition,classification,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,

Technology status and development of mineral wool made of blast furnace slag

Under the trend of low-carbon economy,the technique of producing mineral wool insulation material from molten blast furnace slag are of great significance both to Insulation materials industry and metallurgical industry on the aspects of energy conservation and emissions reduction.This paper presents characteristics and use of mineral wool made of blast furnace slag,and also introduces mineral wool production process and key techniques.It also put forward a number of issues need to be addressed in the process.The inherent mechanism affecting the performance of the of mineral wool is analyzed.And it points out the target and future direction of R & D in Baoshan Iron and Steel in mineral wool technology field.

Carbon Ramming Materials for Blast Furnace Construction

1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality ap- praisal procedure, packing, marking, transportation, stroage and quality certificate of carbon ramming mate- rials for blast furnace construction. This standard is applicable to carbon ramming materials for construction in leveling layer of blast furnace bottom, ramming layer upper or lower the cen- tral line of water cooling pipes, joints between carbon bricks, or joints between carbon bricks and cooling equipment.

Mathematical model of burden distribution in bell-less top blast furnace

The burden distribution in the shaft of blast furnace is known to affect the gas distribution,heat transfer,and chemical reactions inside the furnace.However,the internal layer structure of burden in the shaft cannot be directly measured.Hence,a mathematical model for evaluating burden profile and layer structure was established.A sensitivity analysis based on the model was implemented to elucidate the effect of some factors on the burden distribution,including the stockline height and the mass of central coke.The results show that the width of funnel zone widens with the increase in stockline height,and the mass percentage of ore to coke in this zone slightly increases.Besides,the mass of central coke shows a significant influence on the width of coke channel,and 2%of batch mass of coke is recommended to implement central coke charging operation.The model has been indirectly verified by the gas temperature in operating blast furnace and successfully applied to online evaluate burden distribution.

Heat distribution model under hydrogen-rich low-carbon conditions in blast furnace

Low carbon development of blast furnaces is one of the key technological directions in the current development of ironmaking.Owing to the differences in the physical and chemical properties of hydrogen and carbon,hydrogen-rich media entering a blast furnace will change the heat distribution,thus affecting the stability of production.Accordingly,a heat distribution model was proposed to study the temperature distribution in a blast furnace,simultaneously considering gas-solid heat exchange,slag and iron melting,and chemical reactions.The model was used to analyze the temperature distribution of a 2300 m^(3) blast furnace and was verified via comparison with actual production data.Subsequently,the effects of the injection rate of hydrogen-rich media,H2 concentration,and oxygen enrichment rate of the blast on the temperature distribution were investigated.Results indicated that the increase in the injection rate of the hydrogen-rich media decreased the amount of direct reduction and led to an increase in the furnace temperature.Furthermore,an increase in the oxygen enrichment rate led to a decrease in the furnace temperature,but could reduce the solid fuel ratio,while the change in H2 concentration had less effect on the temperature distribution.The combination of hydrogen-rich media injection and the increase in the oxygen enrichment rate would help to adjust the temperature distribution to the same level as the conventional blast furnace conditions.

Burden Distribution for Bell-Less Top With Two Parallel Hoppers

The circumferential burden distribution of bell-less top with two parallel hoppers was analyzed to obtain the expressions of burden flux and uneven ratio. The four-batch feeding spirally with two parallel hoppers was proposed to realize even burden distribution by uneven flux, ensuring reasonable distribution of BF gas and effective usage of heat energy and chemical energy of gas as well as stable BF production with higher quality and lower consumption.

3-D temperature distribution of a full size BF copper stave with oblate channel

An experiment of a new type full size copper stave for a real blast furnacewas carried out in a special-designed experimental system. The 3-D temperature distribution insidethe stave including isotherm was obtained based on the experiment data. And the effects of thetemperature of cooling water and the velocity of the water as well as the temperature of the furnaceon the 3-D temperature distribution were obtained. The experimental and calculation results showthat the highest temperature of the hot surface is lower than 90 deg C which is very good for thesolidified slag formation on the hot surface and protecting the stave.

钢渣-矿渣基胶凝材料的协同水化机理

通过胶砂强度试验及X射线衍射仪(XRD)、热失重分析(TG-DTG)、扫描电镜-能谱仪(SEM-EDS)等微观测试技术,对不同配合比钢渣-矿渣基胶凝材料的力学性能、水化产物及其水化硬化过程进行了研究.结果表明:当胶凝材料的n(CaO+MgO)/n(SiO2+Al2O3)=0.90时,其水化后期有较多的水化硅酸钙、水化铝酸钙凝胶生成,微观结构更加致密,力学性能表现最优,28 d抗压强度和抗折强度分别达到20.20、7.25 MPa;pH值的变化反映出协同水化效应的关键在于钢渣活性矿物的溶解和矿渣的二次火山灰反应,钢渣和矿渣的最佳配合比可以保证水化程度有较高的水平.

考虑风口回旋区影响的高炉热风分配模拟

以鞍钢新5号高炉为研究对象,对比分析了空喷及考虑风口回旋区这两种工况下高炉热风的周向分配情况.结果表明:当风口参数相同时,空喷与考虑风口回旋区这两种工况下的热风分配规律相同,即在高炉圆周0°,90°,180°和270°方位的风口风量和鼓风动能较大,45°,135°,225°和315°方位的风口风量和鼓风动能较小;空喷和考虑风口回旋区这两种工况下的风量极差分别为3.65 m^(3)/min和7.29 m^(3)/min,标准差分别为1.32和2.71;空喷和考虑风口回旋区这两种工况下的鼓风动能极差分别为9.93 kJ/s和19.90 kJ/s,标准差分别为3.62和7.41;与空喷工况相比,考虑风口回旋区工况下热风和鼓风动能分配的不均匀性更为明显,热风分配结果更准确.

Burden Distribution Calculation of Bell-Less Top of Blast Furnace Based on Multi-Radar Data

The burden distribution real-time estimation problem of multi-loop charging based on the real multi-radar data is resolved.Firstly , an iterative algorithm is introduced to calculate the radial coordinate of the pile-top.Then , based on the multi-radar data , the burden profile is estimated by a cubic-curve equation at the end of the multi-loop charging.Furthermore , the burden profile before the next multi-loop charging is calculated based on multi-radar data by considering the impact of burden descent.On the basis of these burden profiles , a more accurate thickness ratio of ore to coke （ RO/C ） at the radial direction of blast furnace can be obtained.Finally , an example is given to calculate the burden profiles and RO/C by using the real multi-radar data sampled from Baosteel , which shows the effectiveness of the method introduced.

日钢大型高炉经济炼铁技术的应用效果

经济炼铁是基于系统集成的炼铁技术,运用经营理念指导炼铁生产实践,从而实现炼铁的经营目标。日钢根据自身的原燃料条件和技术经验,在新建3000m高炉时,对炉型设计充分优化,并创新性地把各系统先进技术进行集成应用,为高炉经济开炉及经济运行打下了良好基础。通过采取保障原燃料质量、控制合理的煤气流分布、活跃炉缸、优化渣相等措施,高炉实现了经济冶炼条件下炉况长期稳定顺行,生铁成本优势明显。2023年1-8月,对比沿江沿海25家钢企同类高炉综合生铁成本,日钢大型高炉生铁成本领先82元/t。

首钢长钢8号高炉悬料分析与处理

由于首钢长钢8号高炉发生设备故障无法上料,导致炉内空料线至炉身中部,赶料线后因调剂不及时而造成了高炉悬料。针对此问题,对8号高炉悬料原因、前期表现和恢复过程进行了分析和总结,以期为高炉生产积累经验。

煤气化渣替代矿渣制备超硫酸盐水泥的可行性研究

煤气化渣(CGS)富含硅、铝元素,具备作为胶凝材料前体的潜力,但其颗粒形态粗糙,活性较低。为了解决CGS活性低、利用难等问题,利用CGS部分替代矿渣(BFS),探究CGS替代BFS制备超硫酸盐水泥(SSC)的技术可行性,并借助傅里叶红外光谱、X射线衍射仪、热重分析仪、扫描电子显微镜及能谱仪等微观测试技术对SSC水化产物的微观结构进行表征分析。结果表明,CGS作为制备SSC的原料,能提供初始水化所需要的硅、铝元素,驱动SSC发生水化反应。随着CGS掺量的增加,SSC胶砂的抗压强度呈逐渐减小趋势,而抗折强度受影响较小。CGS的最佳掺量为20%(质量分数),在此掺量下胶砂试样的28 d抗折强度最大,抗压强度也达到43.9 MPa。SSC的水化产物主要是水化硅酸钙、水化硫铝酸钙等凝胶。研究结果显示CGS部分替代BFS完全可用于制备SSC。

高炉渣提取硅制备高性能锂离子电池硅碳负极材料的研究

以高炉渣中提取的硅材料BFSi为硅源、聚丙烯腈(PAN)为碳源制备锂离子电池硅碳负极材料,研究了硅与聚丙烯腈的配比对BFSi@C材料电化学性能的影响。结果表明:BFSi与PAN质量比3∶1时制备的BFSi@C样品在0.5 A/g电流密度下初始充电比容量为1884.99 mAh/g,经过100次循环后,充电比容量仍有1509.32 mAh/g,容量保持率为80.07%;在高电流密度下,BFSi@C材料表现出优异的倍率性能。与商业硅材料相比,BFSi@C具有更高的循环容量和更好的倍率性能,在5 A/g电流密度下比容量高达538.31 mAh/g。

梅钢5号高炉炉墙结厚的原因及炉况恢复

对梅钢5号高炉炉墙结厚的原因及炉况恢复进行了总结。5号高炉开炉以来首次炉墙结厚,主要征兆是全炉水温差下降和炉身静压力曲线值出现偏差。结厚的主要原因:一是焦炭质量劣化,入炉焦炭CRI最高上升至23.6%左右,灰分在12.5%左右;二是烧结矿质量劣化,品位降至57.0%左右,FeO含量降至8.5%左右;三是炉渣(Al_(2)0_(3))最高上升至19.0%左右;四是入炉有害元素含量超标,锌负荷升至0.36 kg/t,碱金属负荷最高上升至3.0 kg/t;五是炉况持续恶化。通过采取发展边沿气流、提高入炉风量、提高炉温加锰矿洗炉等措施,炉况得到恢复。

唐钢2号高炉长稳高效生产实践

长周期稳定顺行是高炉炼铁追求的目标,唐钢2号高炉开炉达产后,通过采取优化炉料结构、提高原燃料质量、优化高炉操作制度、强化管理等手段,高炉日产在8800 t/d以上,利用系数3.0 t/m^(3),实现了高炉的长稳高效生产。

酒钢4#高炉冷却壁破损原因分析及对策

酒钢4#高炉中修开炉运行仅1 a后出现炉腹、炉腰、炉身下部冷却壁大量破损,已影响到高炉的操作及生产稳定。结合4#高炉中修后的生产实际状况,并与3#高炉对比,分析冷却壁破损的原因,并提出相应对策,为缓解炉身冷却壁损坏改善高炉运行提供依据。

不同块矿配比条件下的高炉炉料结构

为实现高炉的经济、高产和高质,邢台某钢铁企业采用了富氧大喷吹的工艺措施。围绕高炉现场的原燃料条件,在低烧结矿比的条件下,研究了调整不同块矿及球团矿等酸性炉料的入炉量对降低软熔带位置、改善料柱的透气性、提高高炉的透气性指数和煤气利用率的影响。研究结果表明:当炉料结构为烧结矿+球团矿+南非矿时,随着南非块比例的增加,软熔带的位置上移,滴落温度升高,最大压差和特征值升高,料柱透气性变差,另外南非块碱金属较高,易损坏焦炭结构,故南非块长期使用时,配加比例不宜超过8%;在烧结矿和球团矿入炉比例一定的情况下,逐渐使用纽曼块、SP10替代南非块,当南非块与纽曼块比例为1∶1时,最大压差和特征值最低,料柱透气性最佳为868 kPa·℃,即南非块和纽曼块均为10%较适宜;随着SP10矿替代比例的增加,软熔带区间变宽,且最大压差和特征值都明显升高,炉料的熔滴性能恶化;由于SP10爆裂性能较差,易导致粉末产生量较多,进一步造成料柱透气性恶化,因此SP10不易超过6%。