全氧高炉风口喷吹烧结烟气的冶炼特征

摘要：建立了高炉或氧气高炉喷吹烧结烟气的数学模型,实现对烧结烟气利用与处理的目的。模拟结果显示：当烧结烟气喷吹温度为1250℃,全氧高炉的炉缸与炉身处各循环200m3/t炉顶煤气时,烧结烟气喷吹量每增加100m3/t,高炉理论燃烧温度降低约134℃,直接还原度增大0.02。随着烧结烟气喷吹量的增加,煤比逐渐增大,炉顶煤气中氮气含量逐渐增大,SO2浓度逐渐降低。当烧结烟气喷吹量达到894m3/t时,炉顶煤气中的SO2质量浓度为214.28mg/m3,与普通高炉相比,降低约1.48mg/m3;氮氧化物质量浓度为45.42mg/m3,低于普通高炉约6.36mg/m3。     

高炉喷吹焦炉煤气工艺分析

通过对焦炉煤气多种用途进行分析,认为用于高炉喷吹是钢铁企业中焦炉煤气的最佳利用途径。通过计算分析理论燃烧温度、炉腹煤气量、炉腹煤气成分及炉缸区总热量与焦炉煤气喷吹量之间的关系,为高炉喷吹焦炉煤气提供依据。     

烟气循环与梯级富氧耦合烧结技术分析

为实现“碳达峰、碳中和”既定目标,高能耗钢铁行业全力推进碳减排工作,加快低碳前沿技术的研发与应用。本文聚焦长流程烧结工序,深究烟气循环烧结工艺与富氧烧结技术的细节问题,开发烟气循环与梯级富氧耦合烧结技术;依据气体特性合理选取烧结机风箱烟气O₂体积分数,在循环烟道支管内形成1%～2%的梯级富氧,将高O₂体积分数(18%～20%)的中高温气流介质供给烧结。该技术重点利用富氧弥补循环烟气中O₂体积分数不足的缺点,提高烧结料层中燃料的燃烧效率,实现低品质烧结烟气余热高效回收、固体燃料消耗降低和烧结矿产、质量提升等多种功能需求。     

高炉喷吹焦炉煤气技术

对高炉喷吹焦炉煤气技术进行了阐述.通过分析焦炉煤气的来源及性质、喷吹量及工岂流程,认为高炉喷吹焦炉煤气是可行的.     

高炉喷吹焦炉煤气技术的研究进展

综述了国外高炉风口喷吹焦炉煤气(COG)技术的研究进展,包括瑞典律勒欧使用风口理论模型模拟高炉风口喷吹焦炉煤气,奥钢联林茨厂和维也纳大学联合对高炉风口采用单、双枪喷吹焦炉煤气的模拟研究,以及喷吹焦炉煤气时在炉子下部形成CO和H2的还原能力分析。介绍了日本高炉炉身喷吹焦炉煤气的基础研究。也介绍了喷吹焦炉煤气的工业高炉及相关结果,其经验可供钢铁企业鉴借。     

燃气喷吹耦合热风循环烧结的热风罩内数值模拟与结构优化

热风烧结耦合燃气喷吹技术是在热风罩内同时进行热风循环烧结和燃气喷吹的一种新型强化烧结技术,该技术能提高烧结矿产质量、降低烧结固体燃料消耗和污染物排放量。当流场均匀性较低时,喷出的燃气易富集、着火和逃逸,严重影响运行安全。为此,本文利用Fluent软件对某烧结厂500 m²烧结机热风罩内流场进行仿真模拟,结果表明：热风进入罩内后偏向于一侧料面,并在进气口下方产生回流死区使得外界空气进入罩内阻碍喷出的燃气进入料面,导致喷吹管附近燃气富集;通过优化罩内结构,使得进入料面的最大风速由6.42 m/s降低至2.72 m/s,料面风速方差由2.70降低至0.25,喷嘴出口区域和料面的最大燃气质量分数分别由1.82%和0.98%降低至1.30%和0.53%,相比原结构分别降低了57.63%、90.74%、28.57%和45.92%;优化后侧部漏风平均风速由1.17 m/s降低至0.22 m/s,相比原结构降低了81.2%,保证了燃气喷吹耦合热风循环烧结系统的安全高效稳定运行。     

高炉富氧喷吹焦炉煤气理论研究

 用计算模拟富氧喷吹焦炉煤气以后高炉直接还原度、焦比、入炉风量、炉腹煤气量、理论燃烧温度和炉顶煤气的变化,同时分析了富氧喷吹焦炉煤气对高炉冶炼可能带来的影响。计算结果表明：在保证高炉热量和理论燃烧温度满足高炉正常生产前提下,选择合适的富氧率和焦炉煤气喷吹量,可以使焦比降低至291kg/t,CO2的排放量减少6.1%,并且提高了煤气利用价值,增加企业的经济和环境效益。     

电炉富氧碳喷吹

如何缩短电炉炉料熔化时间和节约能量的主要对策,一是增加单位时间内投入的电量,即UHP电炉操作;二是输入除电能以外的辅助能源,即采用氧——燃助熔烧咀。这些对策虽然收到了相当效果,但由于变压器容量和烧咀能力等,必有一定的限度。     

焦炉煤气高炉喷吹再发电的分析

分析并比较了焦炉煤气高炉喷吹再发电和直接发电的能量利用率及经济性,计算结果表明,高炉喷吹再发电占有一定的优势。同时对影响能量利用率和经济性的各主要因素进行了分析,为钢铁联合企业选择焦炉煤气利用途径提供了理论参考依据。     

Process simulation of iron ore sintering bed with flue gas recirculation

Abstract

As issues of productivity, quality control, energy efficiency and environmental regulation become ever more important in the iron ore sintering process, controlling combustion inside the sinter bed is attracting renewed interest in terms of flue gas recirculation (FGR) and oxygen or gaseous fuel enriched combustion. The application of combustion control schemes inevitably brings changes to incoming and outgoing gas conditions as well as to plant configuration. The objective of this study is to build a process model of a sintering bed using a flowsheet process simulator and to obtain information on material flows for various process configurations and operating conditions. The process modelling was designed to quantify the heat and mass flow in each of the bed segments, which could then be integrated to represent the overall material and energy flow of the entire bed. Variations in incoming and outgoing gas conditions were compared among different configurations of recirculation using the model.     

Sintering behaviours of iron ore with flue gas circulation

Flue gas circulation is an important method for energy conservation and pollutant emission reduction in iron ore sintering. In this paper the effects of flue gas recirculation ratio on sintering of different iron ores including haematite, magnetite and limonite were studied by illustrating the variation of sinter bed temperature, atmosphere and mineralisation characteristics of different types of iron ores induced by the circulation. It shows that the proper flue gas circulation ratios for haematite, magnetite and limonite are 37, 30 and 25%, respectively. For magnetite ore, preheating and high consumption of oxygen in combustion zone caused more silicate minerals and less acicular calcium ferrite, thereby lowering sinter tumbler strength. As for haematite ore, the rapid change of temperatures of combustion, melting and solidification zones leads to elevated combustion efficiency and increased formation of acicular calcium ferrite, which enhances the sinter strength. When using limonite ore as the main raw material, high oxygen consumption, lower maximum temperature of sintering bed, higher cooling rate and larger porosity of sinter are observed.     

Flue gas recirculation in iron ore sintering process

Flue gas recirculation has been introduced into iron ore sintering process to reduce pollutant emissions. Compared with the conventional process, the sintering indices reduce gradually with decreasing O₂ content in the recirculating gas. With sufficient O₂, the principle on the use of flue gas recirculation is proposed. The heat loss caused by the decrease in O₂ content is compensated by 250°C gas and 0.5%CO. The flame and heat transfer fronts of the sintering bed coincide using mixed gases of no more than 6%CO₂ and 8%H₂O (g). A novel technology of 35.5% flue gas recirculation ratio is proposed with qualified sintering indices.     

焦炉煤气脱硫工艺分析与优化

通过对改良ADA湿法脱硫工艺进行分析,找出提高脱硫能力的关键因素并采取措施,从而提高脱硫效率,降低焦炉煤气的硫化氢含量。     

首钢焦炉煤气系统的优化分析

通过对焦炉煤气系统的优化,将富余焦炉煤气应用于锅炉燃烧发电及合成混合煤气,可有效地降低焦炉煤气的放散,在一定程度上降低发电成本,同时保证转炉煤气系统的稳定,实现循环经济。     

氧气高炉喷吹焦炉煤气数学模型

 为降低氧气高炉炼铁流程中循环煤气脱除CO2及煤气预热成本,提出了氧气高炉喷吹焦炉煤气炼铁流程,并建立了新流程能质平衡数学模型,应用该模型分别对传统高炉、传统高炉喷吹焦炉煤气、氧气高炉（鼓风氧体积分数为30%、40%、50%、100%）喷吹焦炉煤气炼铁流程主要技术参数进行计算并对比。结果表明,传统高炉喷吹少量焦炉煤气（30 m3/t）可降低燃料比13 kg/t,焦炉煤气置换焦炭的置换比为0.433 kg/m3,但是对其他参数影响不大。氧气高炉喷吹焦炉煤气流程随着富氧率提高,炉内还原势提高,CO和氢利用率下降,炉内存在还原剂表观过剩,非全氧鼓风条件下炉内没有发生氮气富集。新流程外供煤气总热值为3 000 MJ/t左右,与传统高炉相比变化不大,对现有钢铁联合企业煤气供需平衡影响较小。全氧高炉喷吹焦炉煤气炼铁流程相较于目前的高炉炼铁流程可节焦43%,增煤33%,总燃料比降低20%。     

活性炭脱硫技术在烧结烟气脱硫中的应用

介绍了活性炭脱硫技术在烧结烟气脱硫中的应用,分析了活性炭脱硫技术的机理和特点,同时阐述了活性炭脱硫技术的现状以及未来的发展趋势。     

活性焦法烧结烟气脱硝率影响因素解析

 为了明确活性焦在烧结烟气净化系统循环使用过程中脱硝性能变化及影响烧结烟气脱硝率的主要工艺参数,提高活性焦法烧结烟气净化效率,通过红外光谱分析和模拟试验研究循环使用中活性焦性能变化及其对脱硝率的影响,并通过生产数据统计分析明确影响活性焦法烧结烟气脱硝率的主要工艺参数及其影响规律。结果表明,经循环使用,活性焦表面酚基和醌基数量增加,对NO吸附量降低,导致活性焦前期脱硝率下降,而氨气预吸附处理可大幅提高其前期脱硝率;随脱硝段高度位置下降,脱硝率经历100%、迅速降低、缓慢升高直至平衡等阶段。其次,脱硝率与氨氮比、O₂体积分数、NO_x质量浓度、解析温度呈正相关,与H₂O体积分数、SO₂质量浓度、烟气流量、活性炭床温度呈负相关,其中,氨氮比、O₂体积分数和NO_x质量浓度对脱硝率影响最大,工艺参数优化过程中应着重关注。     

A laboratory-based investigation into the catalytic reduction of NOx in iron ore sintering with flue gas recirculation

The catalytic reduction behaviours between NO_x and CO in sinter zone were studied as using flue gas recirculation (FGR). Minerals in sinter can act as catalysts during NO_x reduction. The catalytic activity of minerals has the order of calcium ferrite?>?kirschsteinite?>?fayalite. The catalytic procedure includes two steps: iron-bearing minerals are reduced to lower valence oxides by CO, and then NO is reduced to N₂ by lower valence oxides. Improving the generation amount of calcium ferrite, especially acicular-type silico-ferrite of calcium and aluminium (SFCA), contributes to significantly reinforcing the catalytic performance between NO and CO. As the basicity of sinter increases to 2.2, it enables to generate maximum amount of acicular-type SFCA which has larger specific surface areas, therefore facilitates decreasing NO_x emission during FGR sintering.