Energy Consumption in Smelting Reduction

The concepts of theoretical gas utilization ratio, smelting heat of iron ore and effective calorific value of coal were introduced in this work. The practical gas utilization ratio and the gas consumption in the shaft of a reduction unit for smelting reduction were discussed. The Corex process was optimized and the energy consumption was minimized according to the relationship of gas production in the smelting unit and the degree of iron ore reduction in the reduction unit. It was proven that the most important factor for saving energy in smelting reduction process is to use coal with suitable effective calorific value for the smelting heat of iron ore.     

About an important problem in a melter-gasifier

Metallization degree of DRI(R_m) reduces with rising oxidization degree of reduction gas(r_o) and oxidization degree of reduction gas rises with falling metallization degree of DRI.This is a vicious circle exists in present operation of C3000.Fuel consumption(r_F) in Corex increases with falling R_m and decreases with rising r_o. However,r_F obviously increases with the integrated change of R_m and r_o.To increase R_m and decrease r_F,an analysis on energy consumption and its distribution was deployed in...     

Mathematical Model Development of Raceway Parameters and Their Effects on Corex Process

  Corex is an alternative ironmaking process and raceway is one of the important areas to maintain the stability of the furnace. The raceway parameters are well established for blast furnace operation. But for Corex process, it has not yet been established and optimized. Thus, a mathematical model was developed to determine various raceway parameters such as RAFT (raceway adiabatic flame temperature), tuyere gas velocity and kinetic energy. The model provides an idea about the raceway geometry, zone temperature and kinetic energy accumulated in tuyere gas. Besides, all the raceway parameters have been analyzed to find out their effects on the Corex process. It is found that RAFT influences the gasification reaction kinetics and higher RAFT generates more CO in reduction gas, which improves the metallisation degree of the DRI in shaft. It is also found that increased gas velocity and kinetic energy generate more fines and demand more coke to maintain char bed permeability. High coke rate increases the production cost and lowers the production of hot metal.     

Development in smelting reduction processes

Corex process is a smelting reduction process to produce hot metal of blast-furnace quality. Coal is used instead of coke, and this replacement makes production costs of hot metal decrease. Iron ore reduction and melting is separated into two steps: in a melter gasifier reducing gas is generated and melting energy is produced by coal gasification; iron ore is reduced in a shaft furnace. Due to this separation, a great variety of untreated coals can be used. The Corex process is designed to operate under elevated pressure, up to 5 bar. Reducing gas is generated in a fluidized bed by partial oxidation of coal. After leaving the melter gasifier, the gas is mixed with cooling gas to obtain a temperature suitable for direct reduction, i.e. approximately 850–900°C. The fines captured in a hot cyclone are re-injected into the gasifier. Reducing gas is fed into the reduction furnace and ascends through the iron burden according to the counterflow principle. The hot DRI having a temperature of 800–900°C is continuously charged into the melter gasifier, where further reduction is effected and melting occurs. Hot metal and slag drop to the bottom of the melter-gasifier. Analogous to blast-furnace practice hot metal and slag are discharged by conventional tapping.     

钢铁工业的空气消耗与废气排放

 基于工业系统与环境之间的物质交换,建立空气是冶金资源的概念,阐述了钢铁工业空气消耗量、废气产生量、污染物排放量三者间的联系及其对区域大气环境质量的影响。调研核查了若干家钢铁企业,统计其烧结、炼焦、炼铁、炼钢和轧钢等各生产工序,以及高炉-转炉流程、全废钢-电炉流程的空气消耗量和废气排放量。以吨钢为计算基准,给出了中国钢铁工业的资源消耗结构和废物排放结构以及空气消耗和废物排放数据,其中吨钢空气消耗量（以质量计）占吨钢资源消耗总量的85%以上,强调了减少空气消耗和废气产生量对降低污染物排放总量、改善区域大气环境质量的重要性。列举了富氧乃至纯氧燃烧、废气循环再利用、烧结矿竖式冷却换热技术的节能减排案例,指明应用这些关键技术、优化钢铁生产流程和发展全废钢电炉短流程等是大幅度减少空气消耗和废气产生量,进而减少颗粒物、SO₂、NO_x排放量的有效途径。     

钢铁联合企业炼焦过程物质与能量流分析

 对不同炼焦工艺进行了比较,研究分析了钢铁联合企业炼焦过程物质流、能量流、硫素流流动规律,介绍了焦炉煤气综合利用途径。认为传统副产回收焦炉仍将是钢铁联合企业焦化的主流工艺;炼焦过程物质与能量流分析的核心问题是碳素流的转换与耗散,是在一定条件下焦炉煤气利用的合理优化和加热煤气热能的有效利用及余热回收。分析结果表明,焦炉加热用煤气消耗是焦化工序的主要能源消耗;干熄焦是具有显著节能效果的余热回收技术;焦炉煤气优化利用应综合考虑钢铁制造流程的优化和钢厂煤气平衡等多方面因素。     

An Approach for Simulation of Corex Process Smelter Gasifier for Prediction of Coal Rate and Silicon in Hot Metal

A thermodynamic model for the Corex process smelter gasifier focusing on coal pyrolysis as well as on the wustite reduction has been proposed. The compositions of hot metal, slag, and the export gas of the Corex process have been simulated satisfactorily for a given degree of metallization of directly reduced iron (DRI). The minimum coal rate is linked to the given degree of prereduction of DRI and the desired final silicon content in the hot metal.     

COREX工艺质能特点分析

从Corex的实际生产数据和高炉的比较出发，分析了该技术的工艺特点和能耗、原料特点，以及该工艺在铁水质量方面的缺陷及原因。     

邯钢2250热轧加热炉降低单位煤气消耗的攻关成果

结合邯钢西区热轧厂加热炉单位煤气消耗指标的攻关过程,分析了影响该厂加热炉单位煤气消耗的一些 原因,介绍了降低煤气消耗攻关过程中采取的一些有针对性的措施,经过运行,在降低加热炉单位煤气消耗方面取 得了一些成效,对于煤气使用单位有借鉴意义。     

Corex炼铁法的环保优势分析

简述了Corex炼铁法的系统组成、工艺特点和环保优势,并结合工程设计和环评实例对其环保优势进行了深入分析,同时结合Corex副产煤气的利用方式对SO2的减排途径进行了探讨.认为Corex是目前已经工业化了的最清洁的炼铁工艺,环保方面的综合优势不容置疑,但这种优势并不像业界报道的那样无可挑剔,而是应该实事求是地进行全面综合分析,不宜以偏概全和过分夸大,否则就很容易对业界造成误导.     

新型保温材料在海绵钛还蒸炉中的应用实践

镁热还原法生产海绵钛过程中,还原及蒸馏反应炉均需消耗通过加热来控制其反应过程。目前国内炉衬均由耐火砖和保温材料组成,每吨钛耗电在6800kWh／t,与国外相比,热损大、电耗高。本文就如何改进还原炉和蒸馏炉的结构及其温度控制,提高热效率进行研究,实现了降低热损失,延长炉寿命的目的。     

焦炉能耗分析与余热利用技术

焦化产业作为高能耗、高污染产业,具有巨大的节能减排潜力。以焦炉物料平衡和热平衡计算为基础,计算焦炉的热效率,对焦炉的能耗进行分析。采用回收焦炭显热的干熄焦技术、荒煤气余热利用技术和以焦炉废气余热为热源的煤调湿技术,以充分利用焦炉支出热,达到节约能源、改善环境、提高经济效益、降低炼焦耗热量和提高焦炉生产能力的目的。     

熔融还原炼铁工艺的煤气富氢改质预还原

考虑到二步法熔融还原炼铁过程中终还原煤气降温和提高预还原效率的需要,以Corex为例分析了终还原炉煤气富氢改质后用于预还原的优势,讨论了其不利因素和对策.结果表明,对终还原炉煤气进行富氢改质后用于预还原是可行的.     

钢铁生产长流程工序能耗数学模型研究

在物料平衡和热平衡模型的基础上，结合有关的工艺参数，建立了以高炉-转炉-轧钢为代表的钢铁生产长流程的工序能耗模型。利用该模型可获得不同生产条件下各工序能耗的计算最小值和长流程的吨钢可比能耗。同时分析了各工艺参数变化对工序能耗的影响，为今后进一步开展节能降耗工作提供参考。     

用风口耗氧量来评估某些高炉操作制度

从低碳炼铁的角度研究高炉采取的各种操作制度的合理性非常必要。用Rist模型和风口耗氧量来评估增加渣量、提高炉腹煤气量、高富氧高湿度、低硅冶炼等操作制度。研究了增加渣量不仅要增加炉渣的熔化热,而且由于风口耗氧量的增加,将提高直接还原度,提高燃料比。高富氧高湿度冶炼,由于水分解需要消耗碳素,同时附加了热量消耗,使风口耗氧量增加;唯有改善炉身效率,增加间接还原,充分利用炉内煤气热能和化学能,才能补偿风口耗氧量引起的负面影响。目前中国高炉的炉身效率普遍偏低,而低硅冶炼应在提高煤气利用率与低燃料比的基础上进行才能发挥效果。由此提出在种种操作制度下需要关注的方面,供操作者参考。     

氧气高炉技术及炼铁工序能耗初步分析

氧气高炉(以430m^3高炉为例)综合数学模型分析计算表明,氧气高炉采用全氧鼓风、顶煤气循环及煤气加热等技术,可提高喷煤量、降低焦比、提高生产效率,其工序能耗较传统高炉相比降低6.27%。通过对氧气高炉的煤气重整能耗和生产工序能耗的分析对比,认为氧气高炉的总体综合能耗较传统高炉具有一定优势,发展氧气高炉有利于节能降耗、降低环境污染,实现可持续发展。     

电弧炉电能需求的生产实践与评价

电耗是电弧炉的重要技术指标之一,在当前发电行业背景下,降低电弧炉电耗具有显著的经济和环境效益。根据典型电弧炉企业生产数据,系统分析各项工艺参数与电耗之间的关系,并进一步评价了各种方法降低电耗的环境效益。结果表明,优化供电制度和强化供氧是具有良好环境效益的节电手段。对于连续加料电弧炉,天然气喷吹对降低电耗的作用被极大减弱,天然气消耗与电耗的相关系数为-1.13 kW·h/m³,其应用不利于CO₂减排。尽管兑加铁水可以显著降低电耗,但是兑加40%(质量分数)铁水的连续加料电弧炉能耗和碳排放量分别是全废钢连续加料电弧炉的2.25和2.50倍,不利于推动钢铁工业节能减排工作。因此,降低电弧炉电耗需要通过增加电弧炉中化学能和物理热的供应及减少能量损失的手段来实现。     

首钢京唐烧结厂降低生产工序能耗的实践

本文从首钢京唐烧结厂设计实际出发,详细介绍了京唐烧结厂节能的具体措施;采取厚料层烧结、控制原、燃料和白云石粒度、稳定烧结生产、推行低温烧结工艺、生石灰强化烧结、堵漏风、控制点火温度等一系列降低固体燃耗、电耗、煤气消耗以及水耗的措施,同时介绍了烧结余热回收措施。自2009年5月投入生产以来,生产逐步走上正轨,烧结料层厚度达780mm、固体燃耗由投产初的50.11kg/t降低到当前的42.65kg/t,取得了较好的经济效益。     

调节阀对转炉燃气控制系统影响的实证研究

某冶炼厂选用不同型号调节阀对转炉燃气控制系统影响的实证研究,证实两台同型号转炉分别匹配控制原理一致的燃气控制系统,对比不同型号、结构的调节阀在转炉燃气控制系统中应用的利与弊。生产实践结果表明,选择适合该工艺生产的最优调节阀设备,降低了操作难度,达到了节能降耗目的。     

降低攀钢高炉渣碳化电耗的途径

分析了攀钢高炉渣还原碳化的理论电耗构成，并与实际情况进行了对比，找到了造成电耗高的原因，指出“合理利用”从高炉排出的熔融高炉渣的显热、改善冶炼动力学条件、提高电炉的热效率是降低电耗的3个主要途径，同时还应从理论上深入研究电炉冶炼条件下的相关机理和理论，才能解决经济可行性问题。并对电耗可降低的限度进行了预测。