粉焦型焦试验小结

通过实验室的配型煤炼焦、以粉焦为主成型炭化生产铸造焦、粉焦加入复合粘结剂生产铸造型焦等试验,探索出了粉焦型焦的生产条件。经现场小型生产试验验证,认为粉焦加复合粘结剂生产铸造型焦是可行的,可节约能源,提高经济效益。     

文摘

近十年来,日本在炼焦技术上采用了配入型煤炼焦法、煤预热、选择粉碎、煤干燥和连续式型焦制造法以及粘结剂的研制。配入型煤炼焦生产的焦炭占高炉用焦的40％。煤预热炼焦提高了焦炭转鼓强度(DI_(50)~(150))4～6％,非粘结煤使用达到25％。煤干燥将含水9％的湿煤干燥至5％,降低干馏热量约15％,提高产量10％。焦炉设备向大容积焦炉发展并采用计算机自动控制,到1983年末,开工     

关于加热制度和焦炭质量的讨论

冶金焦炭的质量主要取决于煤种和炼焦工艺技术。我国炼焦用谋是贯彻区域用煤的配煤方针,所以我省冶金焦用煤主要来源是徐州地区煤,少量的淮北煤和枣庄煤。众所周知,徐州地区煤主要是气煤和弱粘结性煤,这一类煤在我省各焦化厂的配煤中占很大的比重(一般在70%左右)。由于煤种的选择余地较小,要炼出较好的冶金焦只有从炼焦工艺技术上多做工作,煤的选择破碎,入炉煤预热,型煤混装等新技术的应用是有显著效果的,这里主要针对我省目前的炼焦加热工艺制度对焦炭质量的影响进行商讨。     

焦炭热强度影响因素的研究

利用试验焦炉（SCO）对梅山常用11种单种强粘煤进行了试验,研究了炼焦煤的性质对焦炭热强度影响。研究结果表明,炼焦强粘结煤的粘结性、变质程度和碱度指数是对焦炭热强度的关键影响因素,焦炭的机械强度和碱度指数是内在因素。     

弱粘结性煤生产冶金型焦的科学基础(连载14)

作为实例 ,列举了装置在使用“少先队员煤矿”煤时 (表 43,No.3) ,连续操作两昼夜所获型焦的特性。塑性型煤用板式输送机输送 ,然后装入四孔焙烧炭化炉。炉子的加热制度详见表 46,各炉孔之间甚至于炉孔内蓄热室一侧与焦侧的炉顶空间温度剧烈波动说明 ,必须进一步完善炉子结构、加热制度以及炉组温度的调节。由于所处理的煤粘结性较差 (y=8mm) ,因此过高的炉顶空间温度未引起形成过高气孔率的型焦。但是 ,炉子上部温度剧增 ,造成部分型煤产生裂纹 ,因而降低了整型焦的产率。表 48列出了型焦的工业分析、气孔率和按电阻率测定的焦炭成熟度。…     

在沥青作粘结剂的煤成型过程中水的作用

一、前言宝钢焦化厂采用粉煤中配入型煤的备煤工艺。型煤是将30%的粉煤加入6.5%软沥青,经成型机成型后再与70%粉煤均匀混合,装炉炼焦,借此提高焦炭质量,或增加弱粘结煤的使用量。配型煤炼焦的效果与型煤的质量有关,而成型过程的水分是影响成型操作和型煤质量的主要因素之一。水在沥青型煤成型过程中的作用与水在黄泥煤球、石灰煤球或纸浆煤球中的作用不一样。后者的水与粘结剂一起组成胶体,使物料粘结,然后随着水分蒸发、干涸而获得强     

焦炭热性质影响因素分析研究

焦炭与CO2的溶损反应是焦炭在高炉下部粉化的根本原因，其反应性和反应后强度是焦炭热性质的重要指标。影响焦炭热性质的主要因素是煤的变质程度、粘结性、灰分以及煤中矿物质等。除此以外，炼焦工艺条件及焦炭的微观结构类型也对焦炭热性质产生影响。目前国内外大型钢铁联合企业都根据自己的实际情况选择控制焦炭热性质的方法，建立热性质预测模型，从而准确控制焦炭热性质。     

开发优质铸造型焦充分发挥我省资源优势

炼焦煤是煤炭资源中很宝贵的一部分,在世界煤炭资源中炼焦煤仅占10％,随着钢铁工业的不断发展,不可再生的炼焦煤资源日益紧张;为了扩大炼焦煤源,从50年代起,世界上一些国家就开始研究以弱粘煤、不粘煤为主体的成型煤炼焦技术,并将型焦试用于高炉冶炼中,取得了良好的效果。 在研究成型燃料用于高炉冶炼的同时,一些国家为了扩大炼焦煤源,也采用了粉煤成型技术制取铸造用型焦。通过了生产试验,人们发现铸造用型焦比常规焦炉生产的铸造用焦     

影响型焦热性质因素的研究

从提高冷压型焦质量出发，对以贫瘦煤为基础煤的冷压型焦的热性质和影响热性质的某些因素进行了研究，并提出改进高炉用型焦质量的具体措施。     

实用成型焦的研制

一、前言炼铁是铁矿石在高炉内的还原过程,需要大量的焦炭作为热源。1985年,日本高炉用焦3800万吨,相当每生产1吨生铁消耗焦炭484公斤。这些焦炭一向是用室式焦炉生产的,而且需用粘结性煤为主要原料。若将发电用的非粘结性煤炼焦,其使用比率,经种种努力,最大限度也不超过20％。而世界可供开采的煤炭贮量约6700亿吨,其中粘结性煤不过1/4～1/5,大量的是非粘结性煤。炼铁用焦的生产如能使用这种非粘结性煤,在资源利用或经济效益方面将会发挥出极大的效果。日本钢铁联盟热衷于研究连续式成型焦     

不锈钢除尘灰冷固结团块抗压强度的影响因素

采用冷固结成型法对不锈钢除尘灰进行造块,在微机控制电子式万能试验机上进行抗压强度测试。通过单因子实验,研究闷料时间、持压时间和球团失水各因素对团块强度的影响规律。并设计正交实验研究了石墨粉、水分、蔗糖和团压压力4个因素对球团强度影响的主次性。结果表明,闷料步骤对不锈钢除尘灰冷固结成型至关重要,球团失水对提高球团强度作用显著,持压时间对球团强度也有一定程度的影响;石墨粉等对团块抗压强度影响大小顺序为:水分蔗糖石墨粉团压压力。并且得到最优配比(质量分数):配加水分为13%、蔗糖为13%、石墨粉为11%,团压压力为30 MPa,此时球团可获得27 MPa以上的抗压强度。     

Biomass Residue Briquetting and Characterization

All kinds of biomasses pull carbon out of the air as they grow. Waste biomass can be made into usable fuel by densification. These biomasses can then replace some coal in power plants, which will reduce carbon emissions and greenhouse gas effects. Densification of low-density biomass (agricultural and agro-industrial waste) is called biomass briquetting. The briquette form facilitates easy transportation, enables better handling and storage, and is efficient to use as an alternative fuel to coal and firewood. The high temperature developed during the high-pressure densification process assists the inherent lignin, which is the binder in the biomass, to bind the biomass and form a densified fuel called briquettes. In this paper, four kinds of biomasses (mango leaves, eucalyptus leaves, wheat straw, and sawdust) were briquetted. Physicochemical and thermochemical characterization of the biomass residues was carried out by using standard methods. A hydraulic press and an automatic compression testing machine were used for the briquetting and testing. The effect of various parameters, such as compression pressure, pressure application rate, holding time, particle size, and moisture content, on the density of the briquettes was studied. The impact resistance test was carried out by using the standard ASTM method. All the briquettes prepared from the biomass studied in this paper have more heating value than half of Indian coal; thus, they can be used as an alternative to coal and firewood.     

Cold Briquetting of DRI Fines for Use in Steel Making Process

DRI fines, generated during its manufacture and handling, generate high content of fines in the size fraction less than 2 mm. It has iron content above 80%. It is difficult to directly use such iron-rich material in the primary steel making process, without agglomeration. At JSW Steel Vijayanagar, around 50 to 70 tons per day of DRI fines with < 2 mm size fraction get generated. The fines are used in base sinter mix or it may be agglomerated suitably to use it as a coolant in the primary steel making process. Since the fines are extremely reactive, they are susceptible to oxidation if it is not agglomerated as soon as it is generated. The present study brings out the development of an agglomeration process for the DRI fines to a dense metallized briquette, for use as a coolant in basic oxygen furnace. Initially, the conditions for briquetting such as use of binder, hardener, lime, dust, moisture, briquetting and curing conditions were established in a 10 kg batch size. This was followed by industrial-scale processing, at 500 kg batch size. The physical and chemical characteristics of the fines and briquettes were assessed at different stages. The cold compressive strength of the cured briquette was found to be a function of moisture content. The handling parameters in the production condition, for long-term pile-up of briquettes against oxidation, were brought out. The successful use of the briquettes in basic oxygen process was demonstrated.     

Development and use of mill scale briquettes in BOF

Generation of high iron containing wastes such as mill scale, dust and sludge are inevitable in steel making process. It is important to develop and implement processes to recycle and re-use these wastes. An attractive option is to recycle these wastes through BOF steel making process, but is not suitable for handling and efficient operation in available forms. Present work shows the briquetting of steel making wastes using various binders in a pilot scale briquetting machine. In briquetting tests, the effecting parameters have been studied for determining the best combination of binders and operating parameters. A process for briquetting mill scale in optimum combination with CRM dust and BOF dusts using an organic binder has been established. Separate indices were formulated as acceptance criterion for use of mill scale briquettes in BOF service conditions involving dynamic, crushing, abrasive and thermal loads. Subsequently, series of trials were conducted with use of mill scale briquettes as secondary coolant replacing iron ore in 130T LD converter. The present paper compares the effect of mill scale briquettes vis-à-vis iron ore on process parameters in BOF steel making and also highlights its operational advantages.     

BRIQUETTING OF FINE SIZE ASPHALTITE WITHOUT BINDER

ABSTRACT

In this study, the effects of particle size, moisture, briquetting pressure, and preheating temperature were investigated on briquetting without binder of S?rnak Asphaltite, having a particle size of—20 mm, 46.22% ash, 5.83% total sulphur content, and 4900 kcal/kg calorific value. At the end of the briquetting experiments; mechanical strength values of briquettes produced in optimum conditions (particle size, ? 1 mm; moisture, 3.6%; pressing value, 4 t/cm²; amount of lime, 12%) have the properties of first-class briquettes according to Turkish standards. The mechanical strength values of produced briquettes were affected positively in optimum conditions with preheating to 80°C. In combustion experiments using an upper burning stove, the combustion efficiency of briquettes, which contain 50.54% ash, 16.08% fixed carbon, 33.38% volatile matter, and 4.80% total sulphur have been calculated as 60%. During the combustion, sulphur content in smoke gas and particle emissions were determined as 2.34% and 3 mg/m³, respectively.     

Increasing the sustainability of steel production in the electric arc furnace by substituting fossil coal with biochar agglomerates

Biochar fines from a wood gasification plant and from pyrolysis of agricultural residues were investigated as substitutes for fossil coal used in the steel production in the electric arc furnace (EAF). During previous tests biochar fines with high specific surface showed problematic burn-off behaviour. Therefore the agglomeration behaviour of the biochar fines was investigated. Different binary and ternary mixtures of biochar with water and binders were tested in a hydraulic stamp press and evaluated with regard to green strength and fatigue strength of the briquettes after 3 days. One selected mixture was used to produce pillow briquettes in a double roll press. The abrasion behaviour of the produced briquettes was tested and compared to an anthracite reference coal (RC). Melting tests in a pilot EAF showed that the agglomerated biochar reacts similar to the RC. The briquetting leads to reduced reactivity and slower burn-off compared to the biochar fines.     

钼精矿焙砂压力成型的工艺过程研究

着重研究了适合于钼精矿焙砂压力成型的原料粒度组成，提出了相应的破碎流程。此外，还就预先碾压对于成型过程的影响进行了研究，并得到了肯定的结论。采用这一工艺过程进行连续成型试验，成球系数达到８６．５％。     

解决热压成型工艺作业率低的途径之一

分析了原热压工艺流程循环废气风机作业率低的原因,介绍了新热压工艺流程解决问题的方案。     

Utilisation of low-grade raw materials for preparation of reactive catalysed-coke for blast furnace application

In this work, a method for producing highly reactive catalysed coke from medium and non-coking coal using low-grade iron ore fines as a catalyst through two different alternate routes, namely carbonisation in a stamp charge coke oven and carbonisation in a horizontal tube furnace was attempted. Phenolic resin and petroleum pitch were individually experimented as a binding material to get adequate strength. Effect of process parameters such as coal-to-iron ratio, briquetting load, binder quantity and coking to non-coking coal ratio on the coke properties such as reactivity and mechanical strength was investigated. The SEM and petrography analysis of catalysed coke were used to study the microstructure and its effects on reactivity.     

含铁尘泥压块高温强度劣化规律及机制

摘要：基于Oxycup工艺,以高炉工序的重力除尘灰和转炉工序的转炉污泥作为主要原料,配加一定量的粘结剂制成复合压块,通过开展模拟实验和基础分析,研究含铁尘泥压块强度的劣化规律和劣化机制。结果表明：水泥粘结剂的加入能有效抑制含铁尘泥压块的体积膨胀,稳定含铁尘泥压块的内部结构,从而保证含铁尘泥压块的高温强度;水泥粘结剂压块的致密度要高于羧甲基纤维素钠粘结剂压块,且在水化过程中会生成氢氧化钙,会对铁氧化物还原起到一定的促进作用,从而使得水泥粘结剂压块的还原性强于羧甲基纤维素钠粘结剂压块;水泥粘结剂压块由于水泥石相固结作用的存在,使压块强度有了显著的提高,随着温度的提高,水泥粘结剂逐渐失效,但失效后的水泥石仍能保持一定原始形态,能够稳定压块的内部结构,使压块强度劣化的同时仍能保持一定的基础强度。