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In order to improve blast furnace efficiency, reduce CO2 emission and accelerate energy utilisation, a new preparation process of iron coke hot briquette (ICHB) based on the raw materials conditions in China, a new type blast furnace ironmaking burden, was experimentally investigated in this paper. The new preparation process was researched and optimised through single factor experiment and orthogonal experiment. Meanwhile, the reactivity and the post-reaction strength of ICHB prepared under the optimised conditions were tested and the effect of ICHB on the thermal performance of conventional coke was researched. In addition, softening and dripping properties of mixed burden with optimised ICHB charging was simultaneously investigated. The results showed that the optimised preparation parameters of ICHB include 15% iron ore, 65% bituminous coal, 350°C hot briquetting temperature, 1100°C carbonisation temperature and 4 hours carbonisation time. The reactivity and the post-reaction strength of ICHB prepared under the optimisation conditions are 62.4 and 10.6%, respectively. ICHB has protective effect on conventional coke and the protective effect is more obvious with 10% ICHB adding. With the increase of ICHB charging ratio, softening interval T40–T4 of mixed burden is widened while melting interval TD–TS (namely cohesive zone) is narrowed. Additionally, the permeability of mixed burden becomes better and dripping ratio is first increased then decreased. The suitable charging ratio of ICHB in mixed burden is about 30%. 相似文献
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《钢铁冶炼》2013,40(4):288-292
AbstractDisposal of waste plastics is a serious global issue, and hence it is imperative to explore methods to recycle them for efficient utilisation. The coke making process is considered to be a promising area to which the thermal decomposition of waste plastics is applicable, because the process involves coal carbonisation at a high temperature under a reducing atmosphere. As an outcome of the research work carried out on a laboratory scale followed by plant trials at Tata Steel, it was found that waste plastics recycling process using stamp charged coke ovens is feasible to recover coke, tar, light oil and gas from general waste plastics mixed in coal by carbonisation in coke ovens. It has also been established in the laboratory that waste plastics up to 1% can be used in coke making without any deterioration in coke strength. Plant trials have also indicated that co-carbonisation of waste plastics with coal is a possible solution for its disposal. 相似文献
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在南钢40kg实验焦炉开展配加非炼焦煤炼焦实验,研究了在配煤中添加煤粉改性剂(zzz)对配合煤、焦炭质量的影响。采取不同配量的改性剂添加方案进行配煤炼焦实验,通过实验确定出最佳配煤方案:非炼焦煤配加量达到15%(粒度小于3mm),煤粉改性剂添加量为0.10%。最佳配煤方案中添加改性剂与未添加改性剂炼出的焦炭质量相比,灰分、硫分基本保持不变,抗碎强度M40增加14.35%,耐磨强度M10下降6.00%,反应性降低5.5%,反应后强度提高5.93%,实验结果表明:焦炭冷态强度与热态性能指标均接近于南钢生产配煤焦炭质量。 相似文献
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Thecokesolutionlossreactionisoneofthemostimportanteffectsresultingincokepulverizinginblastfurnace .Thefactorswhichaffectreactionincludecokeporestructure ,micro crystalstructureonporewall ,thecontentandconstituentofminer als ,etc .Amongthesefactors ,theconstituentofmineralsisemphasizedallovertheworldinrecentyears .Buttheemphasisofmoststudieswasputontheeffectofalkalimetals (K ,Na)oncokesolutionlossreactionandtheeffectofotherelementswassel domreported[1-5] .Theeffectofthirteenmineralsoncokesolut… 相似文献
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为了解顶装焦和捣固焦在性能指标上的差异,利用300 kg试验焦炉研究了不同焦肥煤配比对顶装焦和捣固焦性能的影响规律。研究发现,焦肥煤配比由30%提高到60%,捣固炼焦可以改善焦炭冷热强度,且改善作用逐渐减弱;焦炭镶嵌结构体积分数逐渐升高,而同性结构体积分数逐渐降低;焦炭平均孔径逐渐升高,气孔率逐渐降低。焦炭的反应后强度随镶嵌结构体积分数的增大呈现升高趋势,而反应性随各向同性总和ΣISO体积分数的升高而升高。相同配煤结构情况下,捣固焦平均孔径偏低,气孔壁厚度增加,气孔率低约20%。 相似文献
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《钢铁冶炼》2013,40(2):87-90
AbstractThe scarcity of good quality coking coal for the blast furnace (BF) has made steel makers look for an alternative iron-making process that requires little or no coke. The Corex process has been developed as an alternative to BF iron-making, which uses non-coking coal and a small amount of coke as fuel, and pellet/lump ore as iron-bearing feed. JSW Steel operates two Corex units each of 0?8 Mtpa, commissioned in 1998 and 2001 respectively. Iron oxides and non-coking coals have to meet certain physical, chemical and high temperature properties for stable operation and to attain high performance levels. Experience of the Corex operation with various coals and iron oxides over the years has helped in understanding the influence and sensitivity of raw materials on its performance and develop new raw material specifications. Statistical analysis of plant data showed that the significant parameters affecting fuel rate and production are moisture, volatile matter, char strength after reaction of coal, reduction disintegration index (RDI; %, –6?3 mm) of pellets and slag rate. This helped achieve the most efficient operating parameters, surpass rated capacity and utilise steel plant waste. The present paper brings out the impact of various raw material properties, and the modified specifications of coal and iron oxides for Corex. 相似文献
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高炉炼铁是主要的铁水生产工艺,低焦比炼铁一直是高炉节能的重要指标。研究了高含碳金属化团块在高炉中的应用,以达到节约焦炭的目的。利用超细氧化铁粉和非焦煤煤粉为原料在管式加热炉中通过直接还原制备了碳质量分数为15.6%的高含碳金属化团块;在模拟高炉环境的条件下,考察了团块质量变化、团块部分反应后抗碎强度变化和团块微观结构变化;利用自制的热重装置考察了团块内碳的气化动力学;以试验结果为基础,结合高炉数学模型,对利用高含碳金属化团块实现高炉炼铁节约焦炭的效果进行了定量分析。试验结果表明,在高炉环境下,团块部分反应后抗碎强度可以保持在1 200 N/个以上,团块的反应主要为碳溶损反应,且团块有较高的CO2反应性。对2 500 m3高炉的模拟结果表明,在高炉的含铁炉料层中添加质量分数为5%的高含碳金属化团块,生产率可以提高419 t/d,生产1 t铁水可以节约焦炭11.3 kg,且高炉的操作参数不需要进行调整。 相似文献
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为了降低焦炭成本、减少主焦煤、增加低价气煤在配合煤中的用量,以2种气煤、2种肥煤、2种焦煤、1种瘦煤和1种自主研发的煤粉改质剂为原料,在2 kg实验室炼焦炉上开展了大比例气煤改质炼焦试验。试验结果表明,当主焦煤配比低于50%,气煤配比达到35%时,所炼制焦炭的质量指标将急剧恶化,其反应性(CRI)大于36%,反应后强度(CSR)低于50%,不能满足中、大型高炉顺行需求;但在改质剂的作用下,使用气煤逐步替代主焦煤炼焦时,所炼制改质焦炭的热态强度指标均得到显著改善,尽管配合煤中气煤配比提升到45%,主焦煤配比降到40%,仍能生产CRI小于30%,CSR大于58%的改质焦炭。结合SEM、XRD和Raman检测分析焦炭微观层面的差异,结果表明,在炼焦配合煤中添加大剂量气煤,会增加焦炭气孔的数量和尺寸以及无定型碳含量,同时降低焦炭微晶单元的体积和致密度,导致焦炭反应性增加,反应后强度降低;添加改质剂后,上述现象在改质焦炭中可得到显著改善,并且高比例气煤添加下所炼制改质焦炭微观结构和组分的分布可达到高比例主焦煤配加下所炼制生产焦炭的水平。最后,通过工业性试验验证了在改质剂的作用下向炼焦配合煤中添加45%气煤生产优质冶金焦炭是可行的,找到了一种节约主焦煤、降低炼焦配煤成本的新方法。 相似文献
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简要介绍了现行焦炭反应性试验方法的来源,主要表达焦炭在高炉内进入风口回旋区前抗CO2,气化能力以及反应后的抗粉化能力,是一种规范性试验方法。回顾了国内外对焦炭反应性的认识和变化,20世纪认为反应性表达焦炭在高炉抗CO2,的气化能力,反应性高反应后强度低对高炉生产不利。进入21世纪,新日铁提出反应性只是表达了焦炭的活性,认为提高反应性可以提高高炉反应效率,对高炉生产有利,不同时期认识水平不同认知也会完全相反。通过CO2,含量和反应温度对焦炭反应性影响试验和高炉碳平衡计算,分析了喷吹煤粉高炉内焦炭的行为.确定了焦炭进入风口回旋区前的反应失重率。提出现行国家标准“焦炭反应性及反应后强度试验方法”的反应性表达的是焦炭与CO2,反应的活性,高炉内焦炭反应失重率控制因素是矿石的还原性能和未燃煤粉率,与焦炭实验室测定的反应性无关。 相似文献
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《钢铁冶炼》2013,40(6):416-420
AbstractThe blast furnace coke quality depends on the characteristics of coal blend, precarbonisation techniques adopted such as stamping, vibrocompaction etc., and coking conditions. Of the above, coal blend plays a significant role in the production of quality coke. Furthermore, the quality of the blend depends on the quality of individual coals and their interaction making up the blend. Coal, being a highly heterogeneous material, requires special care for determination of its properties and blending of individual coals for coke making. Coal fluidity is one such important coking property which highly influences the coke quality. The hard coking coals having good fluidity, which yield good coke, however are not only very expensive, but also are limited in reserves. Unlike, other properties, coal loses its fluidity on weathering, i.e. oxidation in presence of air on long storage in the yard, and the fluidity value changes on blending with different coals. To understand the effect of coal fluidity on coal blending and there by the coke quality, studies have been conducted using the industrial scale coals and coal blends. An empirical relation has been developed between actual blend fluidity and calculated fluidity using logarithmic weighted average from fluidity of individual coals. Blending of non-coking coals above 20% with the hard coking coals used in this research decreases the blend fluidity and impairs the coke quality. It was seen that the coals lose their fluidity on weathering, and the value becomes less than half after a two months of storage at site. Weathering appears to be more rapid in case of semisoft than hard coking coals. The present paper discusses the influence of coal fluidity on coal blend fluidity and changes on weathering. 相似文献
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针对鞍钢鲅鱼圈所处中国东北部港口的独特地理位置特点,建立了适合鞍钢鲅鱼圈的煤岩配煤方法,分析了鞍钢鲅鱼圈配煤方案工程应用中各煤种用煤特点,考察了工程应用配煤方案的煤岩特征,并对应用煤岩配煤方案所得焦炭质量进行了分析,论述了鞍钢鲅鱼圈开展煤岩配煤技术为企业所创造的经济效益。结果显示,鞍钢鲅鱼圈通过煤岩配煤技术的研究开发与应用,使炼焦用煤结构从以肥煤为主向以进口炼焦煤为主、国产劣质炼焦煤为辅的低成本炼焦用煤结构转变,在满足大型高炉用焦质量要求的前提下,不断优化配煤方案,逐步提高焦炭质量,使焦炭的反应性从27.36%下降到24.95%,反应后强度从62.20%提高到65.37%以上。 相似文献
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Coke microtexture and microstructure is a function of feed coal composition and carbonisation process. If the process remains constant, the composition plays a vital role in developing the microtexture and microstructure which also reflects the coke quality. Knowledge of the influence of coal composition and characteristics on coke quality is a must for formulating a coal blend for coke making. To better understand how the coal transforms into coke requires the ability to correlate the microtextural and microstructural features to coal properties. Petrography is an important tool for comparing the feed coal and corresponding coke. In the present study, cokes manufactured from single coals and two-component blends under similar coking conditions were studied under the microscope to provide valuable information to coke makers. Not only the rank and quantification of macerals but also the association of macerals and minerals play an important role. Also the size and type of inertinite affect the coke quality. Micro-cracking, crack lengths and fissures identify the zone of weakness, whereas microtexture of cell walls suggests the strength-controlling parameters of coke. Pictorial concept followed in the present study is given below: 相似文献
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Precise prediction of the end of carbonisation possesses intangible benefits in the coke making process. The coke ovens in Tata Steel measure the raw gas temperature (at the gooseneck arrangement in the oven top) to identify the end of coking. Based on the gooseneck temperature profile, the carbonisation time is divided into active carbonisation time (ACT) and soaking time. As the soaking time is varied between 45?min and 1.5?h as per the need, the current study focusses on developing a mathematical model to predict the ACT given the coal blend properties and the operating conditions of the oven. Different statistical methods ranging from linear regression to artificial neural network (ANN) have been used to arrive at a robust model. Piece-wise linear regression and ANN have been found to out-perform the other statistical techniques. However, the ANN model is preferred in terms of the predictability of unseen data. 相似文献