铬矿熔融还原不锈钢直接合金化的热力学分析

 针对铬矿熔融还原法不锈钢直接合金化工艺中的热力学问题,利用热力学参数状态图、化学反应等温方程式等进行了理论分析和计算,为在转炉中用铬矿实现钢的直接合金化的热力学可行性提供了理论依据。结果表明：转炉内用铬矿熔融还原直接合金化是可行的,且必须外加还原剂;增加渣中(Cr2O3)含量,适当提高碱度,可以降低(Cr2O3)开始还原温度;渣中铬氧化物以(CrO)形态存在时,开始还原温度较低;(FeO)含量越低,(Cr2O3)开始还原温度越低。     

两步三段式厚渣层铁浴熔融还原炼铁工艺

针对目前熔融还原设备无法将煤气二次燃烧氧化区与铁氧化物还原区隔离而导致能耗偏高的问题,提出了一种两步三段式厚渣层铁浴熔融还原炼铁工艺,以期利用厚渣层冶炼的方法使得氧化区与还原区的梯度隔离。设计了主反应器铁浴炉尺寸与产能,并建立了工艺的整体静态模型,考察了球团金属化率与铁浴炉炉顶煤气氧化度对工艺煤耗、氧耗以及能耗的影响。在选定的适宜操作参数,即煤气氧化度55%,球团金属化率80%条件下,冶炼1t铁水,消耗球团矿1 869.83kg,煤粉674.07kg,同时得到还原度71%的改质煤气898.44kg。结合反应器的设计产能,反应器可处理球团矿3 793.66kg/(h·m2)。     

确保弃渣含铜较低的三菱工艺

本文详细讨论了确保三菱连续铜熔炼和吹炼工艺产出的弃渣含铜较低的相关因素,重点讨论高效熔炼与渣贫化阶段,尤其是将渣中铜损失降至最低的那些重要的设计特点与生产实践。生产冰铜时,通常认为渣含铜直接与冰铜的品位有关。大多数其他冶炼工艺仅生产含铜30%～63%的冰铜,其中一些工艺要求进一步处理弃渣,以达到满意的铜回收率。相反,三菱工艺通常将冰铜品位控制在67%～69%范围,同时还能将弃渣中铜损失保持在0.6%左右。     

Studies on the Extraction of Manganese from Sea Nodule Residue as Ferrosilicomanganese

Most of the extraction processes developed for the polymetallic sea nodules concentrated mainly on the recovery of strategically important metals viz. Cu, Ni and Co. The residue generated in such processes is quite high enough to upset the environmental balance for industrial scale operation. The economics of the process too cannot be favourable if manganese in the residue is not recovered. In this study an attempt has been made to utilize this residue, containing appreciable amount of manganese (about 20%) for producing ferrosilicomanganese, an important ferroalloy primarily used for deoxidation in the steel industry, through smelting process. In order to have an alloy of standard grade, the residue is enriched in its manganese content, by blending it with ferromanganese slag. Bench scale studies indicate that it is possible to produce ferrosilicomanganese, of the grade required by the steel industry, by reduction smelting of the sea nodule residue with ferromanganese slag. Metal recovery, however, was less because of metal entrapment.     

Application of sessile drop technique (SDT) for study of reduction of FeO in slags: reduction by solid carbon as well as solute carbon

Abstract

With growing importance of smelting reduction processes, experimental research to understand reduction of FeO in molten slag and the foaming behaviour associated therein have assumed greater relevance. In a previous paper, experimental data on reduction of FeO in molten slag in a 30 kW capacity induction furnace have been reported. The present study used around 250 g slag in each experiment was concerned with influence of FeO concentration in molten slag and temperature on foaming and kinetics. The present paper describes a study on the same system carried out using the sessile drop technique (SDT) which, although it uses very small (～25 mg) sample size, is extremely versatile. Moreover, SDT allows one to actually see the reaction occur. An attempt has been made to correlate kinetic data obtained using the present set-up with the data where much larger sample sizes were used. Both solid carbon and solute carbon have been employed in reduction studies.     

铁精矿粉熔态还原炼铁与过程集成

以概念设计的方式,提出了一种新的使用铁精矿粉进行熔态还原炼铁的流程。设计了多级流化移动床预还原反应器和闪速熔态还原炉。放弃了炉内二次燃烧的概念,代之以能量最大回收的原则。通过与汽油合成装置或其他化工装置的集成,构造了一套冶金、化工集成生产系统,从原则上克服了熔态还原炼铁和由煤合成汽油存在的多种问题     

高铁锰矿粉熔融还原生产富锰渣新技术

富锰渣是电炉冶炼硅锰合金的原料,而高炉法是冶炼富锰渣的主要方法,但该方法存在工艺流程长,焦炭消耗量大,铅、锌等易挥发金属影响冶炼等问题。提出了高铁锰矿熔融还原冶炼富锰渣新技术,该技术具有工艺流程短,不需要消耗焦炭,铅、锌等金属可以综合回收等优点。试验研究结果表明,高铁锰矿熔融还原生产富锰渣工艺是可行的,在还原温度为1 400 ℃、还原时间为20 min的条件下,渣铁可以完全分离,铁、锰回收率高。     

CaO－SiO_2－Al_2O_3－MgO－TiO_2渣系熔融还原过程中钛还原

在实验室条下，探讨了铁浴法熔融还原过程中，在ＣａＯ－ＳｉＯ＿２－Ａｌ＿２Ｏ＿３－ＭｇＯ－ＴｉＯ＿２渣系与碳饱和熔铁间钛的还原行为，以及渣中ＴｉＯ＿２含量、熔渣碱度（ＣａＯ／ＳｉＯ＿２）、还原温度、铁浴量等因素对钛还原的影响。     

Foaming during reduction of iron oxide in molten slag

Abstract

Coal based direct liquid ironmaking processes, also known as smelting reduction (SR) processes, are now receiving serious consideration in the industry. However, although several processes have reached pilot plant trials, only one, namely Corex, has been commercialised. In all SR processes, most of the iron oxide is reduced in the molten slag phase and foaming is an important phenomenon. Better understanding of the foaming behaviour will result in design of a more efficient and economic reactor. Accordingly, some basic studies on the foaming behaviour of some typical SR process slags have been undertaken in this work. Experimental data on foaming in a 50 kW capacity plasma reactor are discussed in this paper. The data generated are analysed in terms of foaming index, which is equal to the residence time or travelling time of the gas in the foam layer. The influence of FeO percentage in the slag, slag basicity, crucible surface area, initial slag height, and CaF₂addition in the slag on foaming has been studied.     

不同冶炼温度下转炉炉渣成分及性能的匹配研究

转炉冶炼过程中冶炼温度、炉渣成分与性能等均处于不断变化之中,研究各参数的变化及相互匹配对进一步优化冶炼工艺具有重要意义.基于2种典型成渣过程的生产数据和相关研究成果,对转炉冶炼过程中熔池温度、炉渣成分、炉渣熔点和黏度、磷容量和硫容量等的变化进行了梳理和比较,从热力学、动力学两方面对冶炼过程各参数的匹配状况进行了分析,探...     

Reduction and foaming of FeO containing slag

Abstract

Smelting reduction processes being developed for producing liquid iron using coal and oxygen are attractive because they allow the use of ore fines directly and do not depend on coke. This paper presents a brief review of some aspects of smelting reduction and some results of an experimental investigation carried out on the reduction of 5–20 wt-% FeO in a synthetically prepared slag by various reductants in a plasma reactor. Some results of a simulation of the smelting reduction process by carrying out post-combustion with oxygen lancing over the slag surface are also presented. It has been possible to achieve a steady state condition, namely, 1–2 wt-% FeO in the slag with a slag height of 4–5 cm during periodic addition of a charge consisting of iron ore, coal, and flux. A kinetic analysis of FeO reduction with various reductants is presented in detail.     

电石渣为钙源的硅热法炼镁煅烧过程

电石渣是化工行业用乙炔法生产乙炔气或聚氯乙烯树脂的工业废渣,其主要成分为Ca(OH)2,是高碱性物质,属于较难处理的工业废弃物.现有处理电石渣的工艺都存在不足之处,因此电石渣的综合利用是近年来研究的重点与热点问题.本文提出以电石渣为钙源的硅热法炼镁工艺,可综合利用电石渣,将其与菱镁石、萤石和硅铁制成预制球团,用于真空热...     

CaO—SiO2—Al2O3—MgO—TiO2—FeO渣系熔融还原过程中TiC的生成机理

在实验室条件下，测定了熔融还原过程中ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－ＭｇＯ－ＴｉＯ２－ＦｅＯ系炉渣组成以及不同供碳对ＴｉＣ生成的影响，并进行了热力学分析。研究结果表明：ＴｉＣ的生成机理与工艺条件密切相关。     

Kinetics of smelting reduction of fluxed composite iron ore pellets

Kinetic studies on smelting reduction of unreduced fluxed composite pellets (FCP) and fluxed composite pre-reduced iron ore pellets (FCRIP) have been carried out in an induction furnace. The pellets are charged into the slag layer floating on the carbon saturated molten iron bath in a graphite crucible. The slag basicity was however varied such that it has the same value as that of the pellets charged. The temperature of the slag is varied within the range of 1623K to 1823K for the pellets of basicity 2.0. Kinetic studies show a mixed kinetic model of both diffusion and chemical reaction controlled. While the smelting of FCRIP follows the model expressed as G(or) = 1-(2/3)(α) -(1-α)^2/3, the unreduced FCP pellets initially follow the diffusion controlled model of G(α) = α² followed by a chemical reaction controlled first order model of -ln(1-α) at the latter stages of smelting reduction, where α denotes the degree of reduction. The basicity dependence on the kinetics is not very significant. Comparison of the activation energy values explains that the smelting reduction with pre-reduced pellets seems to be a rather less energy intensive process.     

Fundamental Research of Making Stainless Steel by Smelting Reduction of Chromite

ＦｕｎｄａｍｅｎｔａｌＲｅｓｅａｒｃｈｏｆＭａｋｉｎｇＳｔａｉｎｌｅｓｓＳｔｅｅｌｂｙＳｍｅｌｔｉｎｇＲｅｄｕｃｔｉｏｎｏｆＣｈｒｏｍｉｔｅＤｕＴｉｎｇ；ＹｏｕＸｉａｏｍｉｎ；ＷｕＹｉｅｍｉｎｇＡｂｓｔｒａｃｔ：Ｔｗｏｐｒｏｃｅｓｓｅｓｏｆｍａｋｉｎ...     

Heat transfer in an iron bath of a two-stage smelting reduction process

Mechanisms of the heat transfer by means of iron and slag drops in smelting reduction are discussed. The quantity of slag on the molten iron exists in two forms depending on the different processes: either a thin slag layer or a voluminous slag layer. In the case of a small amount of slag, iron and slag drops are spattered in the free space above the bath furnace. By smelting reduction with a high post-combustion degree, the spattered iron drops are quickly oxidized in the free space. The spattered slag drops transfer heat from the free space to the molten iron. A definition for the heat transfer efficiency in the iron bath of a two-stage smelting reduction process is presented. Experiments on heat transfer were made in an experimental EOF-furnace with 100 kg iron. The post-combustion degree and the heat transfer efficiency were on a high level, because inleaked air was used.     

含磷钢渣碳热还原脱磷及资源化利用的研究现状

摘要：针对脱磷转炉渣中磷资源高效回收及其资源化利用过程中存在的问题,系统总结了含磷钢渣除磷方式及其应用优缺点,并着重总结了不同条件（炉渣温度、炉渣碱度、钢渣中FeO质量分数、碳当量、底吹气体流量、冶炼时间等）对碳热还原气化脱磷的影响规律。同时,以应用前景较好的碳热还原气化脱磷方法为基础,提出了脱磷转炉渣在碳热还原气化脱磷过程磷的流向规律,展望了渣中磷资源回收制备磷铁及其循环利用模式。这为实现渣中磷资源高效回收及处理后残渣资源化利用提供重要研究基础和方向。     

钒钛磁铁矿二步法熔融还原试验研究

与传统高炉流程冶炼钒钛磁铁矿相比,采用二步法熔融还原工艺有利于回收钒钛磁铁矿中的铁、钒和钛等有价元素。本研究分别在990℃、1200℃、1500℃下进行气体预还原、配碳预还原和熔融还原试验,结果表明：熔融还原的渣铁分离效果良好且铁损较低,铁水钒含量高于高炉流程铁水,钛渣品位可以达到或超过理论品位。攀枝花精矿二步法熔融还原适宜预氧化后采用固体碳预还原,其还原温度应等于或高于1200℃;熔态终还原时可不配碳,终还原应控制钛还原度、（FeO）含量在适宜的范围内。     

钨冶炼渣综合回收利用的研究进展

综述了钨冶炼渣中有用金属回收利用现状与研究进展,介绍了黑钨和白钨的冶炼工艺、钨、锡、钽、铌、钪回收工艺与理论、钨冶炼渣的减量化处理研究进展.重选和浮选工艺可回收钨锡,得到钨锡精矿后再进行冶炼,选矿工艺流程简单易工业生产且成本低,但适应性较差,对于较细物料无法有效回收,湿法冶金工艺可回收钨、锡、钽、铌、钪,适应性强但流程复杂,酸碱废水对环境影响大;钨冶炼渣减量化是综合利用的根本要求,目前主要用来制做水泥辅料、建筑胶砂、多孔材料、微晶玻璃等,介绍了目前减量化处理的研究现状.最后提出了问题与建议,钪钽铌稀有金属提取工艺的进步依赖萃取剂和离子交换树脂的发展,可利用材料领域内第一性原理和化学配位理论,研发选择性强的萃取剂和交换容量大的离子交换树脂,解决萃取剂选择性差、离子交换树脂交换容量小、废水量大的问题,从原子层面研究出相互作用机理,最终筛选出高效萃取剂及离子交换树脂.指出选冶联合工艺,开发短流程绿色提取技术、冶炼渣高附加值材料研制技术可能是今后研究的重点.     

熔融还原法冶炼高速钢

对用白钨矿、氧化钼和钒渣冶炼高速钢进行了热力学和动力学的计算与分析。在熔融还原过程中,CaWO3、MoO3、V2O5将被C、CaC2、Si—Fe、SiC还原。反应过程包括:固—固反应、液—固反应、铁浴反应和液—液反应。开发了低温快速还原、控制渣量、抑制沸腾等技术。还原WO3的限制性环节是WO3在熔渣中的扩散,改善渣的流动性,扩大反应界面能加快WO3的还原;使用阻尼剂能有效抑制钼的挥发。用20t的AC电弧炉还原氧化钨矿工业化生产高速钢M-2已取得成功,具有质量高、缩短工序、节约资源、降低能耗、提高成品率和改善环境等优点。综合上述功效,生产每吨M-2钢可节约成本6071元。应用这一新技术,重庆特钢公司累计生产M-2钢7981t。