Determination of Physical and Chemical Properties of Electric Arc Furnace Dusts for the Purposes of Their Utilization

Electric arc furnace dusts are among the most environment polluting wastes. Numerous utilization technologies have been developed for dusts containing up to 4% of Zn and more than 20% of Zn. However, the remaining part of steelmaking dusts are the most problematic ones, as they are mostly dumped generating costs and posing serious environmental threats. This paper provides an analysis of the potential utilization options for dusts containing ca. 10% of zinc generated in a single electric steelmaking shop. Physical and chemical properties of dusts have been determined and examined, and furthermore, results of the studies on the EAFD utilization in production of cement clinker and industrial glass have been discussed. It has been found that a particularly beneficial feature of the production technology proposed is that the iron content exceeds 30%. The influence of the dusts used on the functional properties of the products obtained has been established as well as the environmental impact of the processes and products in question and the dust mass possible to be utilized in the production technology proposed have been determined.     

采用喷吹方法处理钢铁厂的细粉尘

评述了国外近年来应用喷吹方法回收钢铁冶炼过程产生粉尘的研究进展。通过高炉风口喷吹只含有铁氧化物和碳的细粉尘,细粉尘在风口循环区内还原和熔化,会吸收大量的热和影响循环区的火焰温度,应采用在热风中富氧和提高风温来补偿热量损失。事宜 焦炭充填床的粉尘熔化炉,具有很高的冶炼强度。它适合于处理炼钢过程所搜集的各种粉尘,可回收有益金属,分离对高炉冶炼有害的低沸点金属。随着对环保要求的提高,国内在回收细粉尘方面     

Feasibility of Air Classification in Dust Recycling in the Iron and Steel Industry

The potential of air classification of dusts from dry off‐gas cleaning for improved recycling of these dusts is investigated. By air classification, a dust can be separated into a coarse fraction and a fine fraction. Some components which are usually unwanted in recycled dust like alkali chlorides and Zn and Pb are often enriched in the fine dust fraction. Thus, air classification of dust before recycling will allow recycling of an increased amount of dust and, thereby reduce the amount of dust which has to be sent to landfill. The feasibility of such treatment is studied on the basis of estimated investment costs and operating costs. The main factors affecting the feasibility of such a treatment are the capacity of the unit, the cost of landfill of the respective dust, and the fraction of dust which can additionally be recycled after the treatment. The investigation of classification of BF dusts and sinter plant dust shows that economic operation can be reached under the assumed conditions at landfill costs above 35–60 EUR/t for BF dust and 90 EUR/t for sinter plant dry desulfurization and de‐dusting residue. The integration of air classification into EAF dust in‐plant recycling can be feasible, too.     

多源冶金粉尘资源化研究现状及展望

钢铁生产流程中产生了大量冶金粉尘,其中含有丰富的铁、碳、锌、铅和钾等元素,具有非常高的回收利用价值。基于多源冶金粉尘产生工序及成分组成,介绍现阶段冶金粉尘主要资源化工艺,包括水洗提盐富铁工艺、回转窑工艺、转底炉工艺、熔融还原工艺以及湿法深度资源化工艺,分析不同冶金粉尘资源化工艺流程和原理,讨论不同工艺应用的特点和局限性。基于冶金粉尘全量资源化理念,进一步展望多源冶金粉尘火法富集、湿法提取全量资源化工艺,为实现冶金粉尘深度高附加值利用、消除冶金粉尘二次污染提供参考。     

钢铁产业集聚区难处理尘泥处理与全量资源化利用进展

简述了钢铁冶金尘泥现有的处理工艺,具体介绍了回转窑工艺、Oxycup工艺、转底炉工艺。钢铁冶金尘泥目前的处理工艺主要停留在尘泥资源化回收利用的前3个阶段,往往只针对含量较高的部分元素进行分离回收。钢铁产业集聚区的尘泥除了含有 Fe、Zn、Pb、K、Na 等元素,还富集了大量 In、Bi、Sn、Cd等具有高附加值的稀散元素,是宝贵的有价资源。随着国家环保法规和产业政策的要求,钢铁冶金尘泥已经到了必须100%全部回收利用的新阶段。鉴于此,提出了根据各自的成分特征进行基于产品设计的各种尘泥间的协同搭配、单元技术间的科学耦合和系统集成,实现多组分梯级分离和全量利用的技术方案,希望能够为钢铁企业冶金尘泥的全量资源化利用提供参考。      

Recycling of carbonaceous iron-bearing dusts from iron & steel plants by composite agglomeration process (CAP)

A composite agglomeration process (CAP) is carried out to recycle the carbonaceous iron-bearing dusts generated from the Iron & Steel companies in order to reduce the environmental pollution caused by the hazardous dusts and make good use of the valuable elements contained in the dusts. In current study, all the dusts are first made into green pellets and used as one part of agglomeration feeds. Effects of the properties of the pelletised feeds on the agglomeration indexes of CAP and the mineralisation, metallurgical characterisation of the CAP products were investigated. It is found that the dust dosage is increased from 7?wt.% by traditional sintering process to 20 wt.% by CAP. Coke breeze consumption is reduced by 21.25 kg_coke/t_product in the CAP with 20?wt.% pelletised feed proportion, indicating the carbon component in the dusts is effectively utilised. The mineralisation characterisations of CAP products are clarified by using optical microstructure and SEM-EDS analyses. Results also demonstrate that metallurgical performances of the CAP products are good and the CAP products are qualified for blast furnace burdens.     

钢渣中磷分离及回收的研究现状和发展趋势

 中国的钢渣产量巨大,但是钢渣的综合利用率较低,造成了严重的资源浪费和环境负担。钢渣中磷的分离与回收是实现钢渣高效资源化利用的关键所在,对开发新的磷资源和建立“无废渣”炼钢流程具有重要意义。首先分析了钢渣中磷的分布状态,总结了目前提出的从钢渣中分离和回收磷的主要方法及其技术特点,并着重介绍了利用选择性浸出从钢渣中直接提取磷酸盐产品的新技术及其研究进展,分析了选择性浸出的原理和实现钢渣循环利用的冶金工艺流程,讨论了其优缺点,最后对未来钢渣资源化利用的发展提出了建议和展望。     

有色冶金高铁高硅渣炼制生铁的应用探讨

有色金属火法冶炼过程普遍产生高铁高硅炉渣,其产量大、难处理的特点导致了金属资源的浪费,也造成了环境污染。结合有色冶金高铁炉渣化学成分,对其直接作为炼铁炉料做了资源性评价。分析了当前有色冶金渣提铁现状以及提铁产品质量,提出其在耐候钢、部分含铜不锈钢方面应用的新思路。     

含铁尘泥回收及利用技术现状及发展方向

在对含铁尘泥的来源、性质和分类进行界定的基础上,系统地介绍了国内外含铁尘泥处置、回收及利用技术现状,指出了含铁尘泥回收与利用的发展方向,可为钢铁工业含铁尘泥的综合利用提供参考。     

在低铬铸铁改性处理中钒渣的冶金物化条件和作用

 在低铬铸铁改性处理中，VS+Ti+Zn复合孕育剂起着良好的孕育处理作用。从热力学角度分析了钒渣作为炼铁工业副产品得到二次利用的可行性，并讨论了冶金综合处理工艺和冶金物化条件对充分发挥钒渣复合孕育效果的作用。结果表明，钒渣复合孕育剂可有效地细化晶粒，改变碳化物形态；钒渣作为一种钢铁冶炼副产品，取代钒铁具有较大的资源利用价值。     

除尘灰在转炉造渣的初步应用

回收利用八钢炼钢过程产生的除尘灰副产品,制成球用于转炉造渣,通过改善转炉过程化渣条件,实现了炼钢副产品的有效循环利用。     

Direct Smelting of Metallurgical Dusts and Ore Fines in a 125t DC‐HEP Furnace

In the metallurgical plant of LARCO at Larymna, approximately 200000t/y of nickelferrous dust are collected in the gas cleaning systems of the Rotary Kilns (R/Ks) corresponding to an annual production of 100000t FeNi20%. In addition, a stockpile of one million tons of old R/K dust lies close to the plant and the community of Larymna. A “one‐stage” environmentally friendly process has been developed for the recycling of this dust by direct reduction smelting in a DC arc furnace. The industrial adaptation of this process was tested in the 125t DC‐HEP (Direct Current — Hollow Electrode Powder) furnace at Georgsmarienhütte steelwork (GMH) in Germany. About 70t of dust were directly smelted by injection through the hollow electrode of the furnace. The nickel recovery in the metal bath was 93‐99.9%. Final products were low nickel alloyed steel grades and slag suitable for special cement types production. Main cause of the dust generation in the R/Ks is the disintegration of laterite and the ore fines fraction after the ore crushing. Their separation, collection and metallurgical exploitation prior to their feeding in the R/Ks would significantly reduce the amount of the generated dust. Therefore, the smelting of untreated laterite ore fines in the DC‐HEP furnace was also indicatively tested. Thus, a zero residues industrial production process was developed for the recycling of nickel bearing dust and ore fines by smelting in a DC‐arc furnace, since the finally produced FeNi‐alloy and slag are 100% utilized in the steel and cement industry respectively.     

冶金尘泥复合球团自还原脱锌研究与实践

 冶金固废资源化利用是21世纪钢铁行业面临的重大课题,脱除冶金固废中有害元素并回收有益元素成为了其中的关键技术。提出了一种全新的冶金固废提铁脱锌技术,将冶金尘泥制成双层结构的复合球团,并进行了复合球团自还原微爆裂试验研究和工业应用试验。结果表明,将复合球团加入到铁水罐中,取得了良好的还原效果,利用铁水罐余热和铁水的热能预热复合球,致使复合球团产生自还原并发生微爆裂反应,从而为还原反应提供更多的反应界面、更佳的动力学和热力学条件,实现了含铁、锌尘泥的高效综合利用。     

Recycling Waste Plastics in EAF Steelmaking: Carbon/Slag Interactions of HDPE‐Coke Blends

Due to the inherent limitations of current methods of plastic waste disposal, there have been concerted efforts worldwide towards developing alternative, environment friendly and economic recycling processes. With an aim to recycle waste plastics in EAF steelmaking, carbon/slag interactions for a number of blends made of metallurgical coke and HDPE (high density polyethylene) and an EAF slag (34.8 mass‐% Fe₂O₃) have been investigated at 1550°C using a sessile drop arrangement. The rate of gas generation showed an increase with increasing HDPE concentration, reaching a maximum for blend #3 (with appr. 30 % HDPE) and decreasing thereafter. Among all the blends investigated, blend #3 showed significantly higher levels of slag foaming as compared to metallurgical coke. HDPE‐coke blends also showed better wetting compared to metallurgical coke with contact angles in some cases improving from 140° to 70° after 10 minutes of contact. These results have been discussed in terms of ash and sulphur contents of carbonaceous residues and dynamic changes in slag composition. Industrial trials on blend #3 showed a good agreement with laboratory results. This work opens novel avenues for the utilisation of plastics wastes as a valuable carbon resource in EAF steelmaking.     

现代转炉炼钢各工序炉渣的再利用研究综述

钢渣在钢铁企业内部的循环利用将是今后钢渣综合利用的发展方向之一,也是提高钢渣附加值和固体废弃物减排的有效途径。结合炼钢技术发展现状,分析了转炉炼钢不同工序的冶金反应特点和对炉渣的要求,结合不同工序的炉渣产出特点,从系统工程的角度出发,对炼钢厂内部的循环进行了分析,提出了解决问题的思路。     

新日铁发展循环经济的技术措施

叙述了新日铁炼铁、炼钢和轧钢等钢铁生产工序的具体节能措施,分析了新日铁的污染物减排技术措施和社会废弃物再利用技术,主要包括:干熄焦余热回收发电、高炉炉顶煤气余压回收透平发电、焦炉和高炉煤气循环利用发电、转底炉回收含锌粉尘、焦炉煤气提氢技术、建设新一代超级焦炉、废塑料回收为炼焦原料、废轮胎用作转炉炼钢原料、垃圾直接熔融处理与资源化系统等.指出:新日铁以"环境保护"为经营前提,中国钢铁企业应该借鉴新日铁的经验,为环境保护和循环经济建设做出应有的贡献.     

Chromium Recycling from Argon-oxygen Decarburization Dust in Hot Metal Pre-dephosphorization Process

The chromium recycling from the stainless steel dust of an argon-oxygen decarburization (AOD)furnace during a hot metal pretreatment process was investigated.Experiments at different temperatures or with different amounts of AOD dusts were carried out in a laboratory furnace equipped with MoSi2 heating elements and subsequently industri-al experiments were conducted in a stainless steelmaking factory,in order to study the thermodynamic mechanism of C and Si reacted with Cr2 O3 to get Cr from AOD dust.The results showed that the reaction between C and Cr2 O3 occurred below 1 572.18 K.Although its reducing ability was weaker than that of Si,C enabled the Cr in Cr2 O3 in the AOD dust to be recycled using the Si in the slag.By combining the AOD dust added in an earlier stage,the hot metal pretreatment slag added in a later stage could not only recycle Cr from AOD dust but also remove Si,S,and P.Higher hot metal temperatures resulted in higher Cr content and lower remained P concentration in the molten iron.     

用高含铁废渣生产硫酸亚铁和固体聚合硫酸铁的可行性分析

利用白银冶金及化工生产过程中产生的高含铁废渣 ,开发新产品 ,如铁精砂、硫酸亚铁、固体聚合硫酸铁。并对生产工艺流程和经济效益进行阐述和评估 ,用这一方法 ,产品回收率可达 98%以上 ,剩余残渣中富集了Cu、Pb、Zn、Cd、Au、Ag等元素 ,可进一步提炼 ,母液还能用于生产微量元素肥料 ,不仅附加值高 ,而且工艺简单 ,设备少 ,投资小 ,能耗低 ,又无“三废”排放 ,经济效益可观     

首秦资源类固废综合回收利用实践

主要论述了在大力推广钢铁企业绿色可持续发展的大背景下,首秦对厂内资源类固废回收利用的探索和实践。除小部分固废可直接回吃外,首秦通过厂内自建加工线进行加工回吃,实现了大部分固废的回收利用,提高了自消纳率,为企业创效的同时,也为环境作出了积极贡献。2013年以来资源类固废回吃比例达到72%,比2012年提高2.3%。高炉渣通过自建水渣超细磨工艺实现年产水渣微粉约60万t。钢渣通过自建钢渣处理生产线,对渣钢进行干磨深加工,精选出水磨豆钢及钢渣水磨粉两种产品分别返回炼钢和烧结回收利用。烧结和高炉无法自回收利用的烧结机头三电厂除尘灰、高炉布袋灰与炼钢OG泥、氧化铁皮等固废配加一定燃料和皂土烧成红泥砖,烧成砖后破碎成一定粒度,返回炼钢作为冷却剂使用,破碎后的粉末返回烧结使用,后期该工艺改? ＡЫ豪涔糖蛲殴ひ眨档图庸し?0元/t。     

Evaluation and Control of Iron and Steelmaking Slags through Electrochemical FeO Sensor

One of the greatest obstacles to the application of physical chemistry principles to the elucidation of slag‐metal reactions is a lack of knowledge of activities of the reacting species. To a large extent, oxygen potential of the slag phase governs iron and steelmaking practice. Without oxygen control by means of appropriate sensors, the behaviour of the other elements cannot be managed. In this paper, measurements of the FeO activity with various types of electrochemical FeO sensors will be described together with examples of their applications for improved strategies toward better practice for ladle metallurgy and sulphur and manganese distributions between slag and metal phases during steelmaking. Measurements of FeO activity have also been made in order to improve dephosphorization reactions. This type of work has led to significant reduction in volume of slag generated within the steelmaking vessel, which in turn, has important implications for refractory wear, metal yield, alloy recovery and improved productivity. Finally an on‐line sensor is described which permits the oxygen potential to be determined for both the metal phase and the slag phase during steelmaking in the BOF.