捣固炼焦生产焦炭应用于大高炉的研究

针对大型高炉的发展趋势,进行了40kg捣固小焦炉试验和4.3m捣固焦炉生产试验,结果表明,在发挥捣固炼焦工艺优越性的前提下,通过合理配煤,严格控制进厂煤质,捣固工艺生产焦炭完全可以满足大高炉的生产需求。     

捣固焦炭在高炉中的应用

通过开展相同配煤比捣固炼焦与顶装炼焦200kg小焦炉实验、半工业性试验及5.5m焦炉工业生产等对比试验,可知捣固炼焦较顶装炼焦所得焦炭质量有明显改善,捣固炼焦有利于扩大炼焦用煤资源,降低生产用配煤成本。在攀钢大型高炉进行顶装焦炭与捣固焦炭应用效果对比后,可知使用捣固焦炭比用顶装焦炭高炉综合冶炼强度有所提高,增铁节焦效果明显。     

Effects of binder on recovery stamp charged coke making process

The optimum stability of coal cake is essential for producing good quality of coke in stamp charged coke making process. A suitable binder named as ‘X7’ was identified to improve the stability of coal cake, oven throughput, coke quality and reduce specific energy consumption for stamp charged coke making process. Laboratory results show that addition of ‘X7’ in coal blend up to 0.10–0.50 percentage, improved the mechanical strength of coal cake by 3.0–5.0 percentage. Six hundred kg pilot plant trials show that addition of binder in the base coal blend improved coke quality in terms of CSR, M ₄₀ and AMS significantly. Coke plant trials also show that ‘X7’ addition (0.10%) in base coal blend improved coke quality in terms of CSR (1.25 point), M ₄₀ (0.9 point) and AMS (1.70 mm). Addition of ‘X7’ increased Coke End Temperature up to 24°C during plant trials. The increased in temperature saved energy approximately 11 000 Gcal and reduce CO₂ emission by at least 10 000 T/Annum.     

Plastic wastes, lube oils and carbochemical products as secondary feedstocks for blast-furnace coke production

Two plastic wastes (polyolefin-enriched and multicomponent), two lube oils (paraffinic and synthetic) and one coal-tar were assessed as individual and combined additives to coal blends for the production of blast furnace coke. The effects of adding 2 wt.% of these additives or their mixtures (50:50 w/w) on the coking capacity of coal, coking pressure and coke quality parameters were investigated. It was found that the two plastic wastes reduce fluidity, whereas the addition of oils and tar helps to partially restore the fluidity of the coal-plastic blend. From the co-carbonization of the coking blend with the different wastes in a movable wall oven of over 15 kg capacity, it was deduced that polyolefins have a detrimental effect on coking pressure. The addition of oils and tar to the coal-plastic blend has different modifying effects. Whereas paraffinic oil eliminated the high coking pressure caused by the polyolefins, polyol-ester oil had a weak reducing effect unlike coal-tar which had a strong enhancing effect. The compatibility of the oils/tar with plastics and coal and the beneficial influence of these combinations on coking pressure is discussed in relation to the miscibility of the plastic and the oily and bituminous additives, and the amount and composition of the volatile matter evolved from each additive during pyrolysis as evaluated by thermal analysis. Furthermore, it was found that coke reactivity towards CO₂ (CRI) and coke strength after reaction with CO₂ (CSR) are heavily dependent on the composition of the plastic waste, with polystyrene (PS) and polyethylene terephthalate (PET) having a clear negative effect. The porosity of the cokes obtained from blends containing plastic wastes is always higher, but the pores are smaller in size.     

捣固焦在大容积高炉上的应用分析与探讨

近年来钢铁和焦化行业对捣固焦在大容积高炉上的应用进行了广泛的研究实践。分析了焦炭在高炉中的作用、焦炭质量变化对炼铁的影响、不同炉容级别高炉对焦炭质量的要求,介绍了不同钢企大容积高炉用捣固焦的配煤情况及国内2200 m³、3200 m³高炉应用捣固焦的实例。在考察了钢企使用的捣固焦配煤方案的基础上,临沂恒昌焦化股份有限公司进行了捣固焦配煤方案的模拟试验,得出5.5 m捣固焦炉在配煤比例合适的情况下,完全可以生产出符合大容积高炉要求指标的焦炭。建议炼铁行业和焦化行业加强合作,完善捣固焦的质量评价体系。     

Determining the strength of coke under crushing forces

Despite the many characteristics of coal relating to its use as blast-furnace fuel, few characteristics have been proposed to predict the productivity of the furnace and its coke consumption. Drum tests of coke permit ample assessment of its ability to withstand mechanical loads (in particular, abrasive and impact forces). At the same time, models of coke failure in the blast furnace indicate that the crushing forces on the coke play an important role. Thanks to those forces, the mean piece size of the coke declines as it falls though the furnace. The method used to determine the coke’s ability to withstand abrasive and impact forces has been codified in GOST State Standards (in terms of the strength indices M ₂₅, M ₄₀, and M ₁₀). However, there is no standard method for assessing the ability of the coke to withstand crushing forces. To address that deficiency, a compact system for determination of the coke’s ability to withstand crushing forces is proposed: it consists of a press for the creation of compressive forces; a matrix with a punch in which the coke sample may be placed; and an instrument for measuring the compressive force (the crushing force). Values of the compressive strength determined using the new system are presented for various coke samples.     

Pitch and petroleum coke additions to coke oven charges

Several pitch materials and a petroleum coke were added to coke oven charges in an attempt to make good metallurgical coke from Canadian coal of poor coking quality. Coal and petroleum pitches were added to a low fluid western Canadian coal of medium volatile bituminous rank, and the blends coked in a technical-scale moveable wall test oven having a 230-kg charge capacity. Pitches improved coke tumble test indices, the principal coke quality parameter related to blast furnace performance. Varying levels of petroleum coke were added to an eastern Canadian coal of high volatile bituminous rank, and the blends, some partially briquetted, were carbonized in a test oven. Tumble indices of coke from the partially briquetted charges approached an acceptable level. These investigations confirm that petroleum products as well as coal derivative can play a useful part in the production of a metallurgical strength coke from poor or non-coking coals.     

焦炭质量的多参数预测与调控

开展配煤炼焦试验研究，在原传统经验型配煤调控质量指标体系的基础上，增加新的指标参数。预测调控焦炭质量。介绍了多参数预测调控在实际应用中所发挥的作用，通过增加新指标,保障了焦炭强度的稳定．满足了炼铁高炉不同阶段和状态下对焦炭质量的要求。     

焦炭钝化剂在高炉炼铁中的应用研究

在焦炭上喷洒一定浓度的钝化剂溶液,可防止高温下焦炭气孔壁变薄而粉化,减少高温下焦炭破碎,有利于降低高炉中焦炭的热反应性,提高反应后强度,相应增加喷煤量,进一步提高冶炼强度,增加高炉产量。     

Phenolic resin binder for the production of metallurgical quality briquettes from coke breeze: Part I

Phenol based novalac, resol and the blend of both resins were used as binders in briquette production from coke breeze. The effects of the amount of catalyst on the tensile strength of the cured briquette were studied. The results obtained have indicated that the highest tensile strength could not be attained unless the blend of novalac and resol was used as binder. The most suitable blend was the binder prepared from the hydrochloric acid catalyzed novalac of F/P = 0.5 and the N/P = 0.3 catalyzed resol of F/P = 2.0. When this blend was used as a binder the tensile strength of the cured briquettes did not drop even if they were carbonized at 470 °C and 570 °C. Their strengths at these carbonization temperatures were 67 MPa and 72 MPa respectively, and the rise in the temperature resulted in some increase in their strength. These results show the fact that as the formed coke briquettes descends from the top of the blast furnace, the rise in temperature will not deteriorate their strength; it will probably improve their properties. Therefore, only curing at 200 °C for 2 h will be sufficient for the briquettes to be used as substitute for metallurgical coke in the blast furnace.     

Three-dimensional modelling of in-furnace coal/coke combustion in a blast furnace

A three-dimensional mathematical model of the combustion of pulverized coal and coke is developed. The model is applied to the region of lance-blowpipe-tuyere-raceway-coke bed to simulate in-furnace phenomena of pulverized coal injection in an ironmaking blast furnace. The model integrates not only pulverized coal combustion model in the blowpipe-tuyere-raceway-coke bed but also coke combustion model in the coke bed. The model is validated against the measurements under different conditions. The comprehensive in-furnace phenomena are investigated in the raceway and coke bed, in terms of flow, temperature, gas composition, and coal burning characteristics. The underlying mechanisms for the in-furnace phenomena are also analysed. The simulation results indicate that it is important to include recirculation region in the raceway and the coke bed reactions for better understanding in-furnace phenomena. The model provides a cost-effective tool for understanding and optimizing the in-furnace flow-thermo-chemical characteristics of the PCI operation in full-scale blast furnaces.     

Effects of weathered coal on coking properties and coke quality

Determinations of weathered coal by petrographic methods, and coking tests in an 18-inch ($\text{≈}\text{1}\text{2}\text{m}$) test oven were used to quantify the effects of weathered coal on coking properties and coke quality. The results show that the presence of weathered coal causes a decrease in coke stability and coking rate and an increase in coke reactivity and coke-breeze generation. Because these effects contribute to increased costs in both the coke plant and the blast furnace, every effort should be made to reduce the amount of weathered coal in coking coal mixes.     

大型高炉用焦炭配煤技术的研究与实践

为满足大型高炉生产需求,开展了大型高炉用焦炭配煤技术的研究与应用工作。通过细化煤种分类、合理评价炼焦煤综合性能、优化配煤结构、确定合理库存等方法使焦炭质量达到了大型高炉生产需要的指标。     

Producing high-quality coke from blends of domestic and imported coal at PAO Zaporozhkoks

The evolution of quality requirements on blast-furnace coke indicates the need to use low-sulfur imported coal of the required quality. The best performance characteristics of European blast furnaces are noted. At such furnaces, with the injection of pulverized coal, the consumption of low-reactivity blast-furnace coke is 280.9–355.8 kg/t of hot metal. On the basis of the requirements imposed on coal used in the production of low-reactivity, low-sulfur, high-strength coke, an industrial coking method has been developed and tested at PAO Zaporozhkoks on the basis of Ukrainian, Russian, and United States coal of the required quality. The coke produced is tested in blast furnace 5 at PAO Zaporozhstal’. The results show that coke of improved quality may be obtained from batch containing 50% Ukrainian coal, 30% Russian coal, and 15% United States coal at PAO Zaporozhkoks. Thus, in the first 11 months of 2013, the quality of the blast-furnace coke produced was as follows: moisture content 3.6%; ash content 11.0%; sulfur content 0.78%; M ₁₀ = 6.3%; content of the >80 mm class 4.1%; content of the <25 mm class 3.1%; CRI = 31.8%; CSR = 51.9%.     

Production of coke with ore additives in coke furnaces

Coke with ore additive may be produced from Zarechnaya DG coal (Kuznets Basin) and high-sulfur Zh coal (from Samsonovskaya and Krasnolimanskaya enrichment facilities, Donets Basin), which is of low technological value and is used in small quantities in batch for the production of blast-furnace coke. The ore additive employed is dust from the dry gas purifiers in the production of commercial silicomanganese, manganese-carbonate concentrate, and manganese-oxide concentrate of the first and second kinds. In experimental batches, the content of the ore additive is adjusted in 5% increments over the range 0–15%. On introducing the ore additive in the batch, the corresponding quantity of G coal is removed, with constant content (40%) of Zh coal. Experimental batches are coked in a 5-kg laboratory furnace (designed by Ukrainian Coal-Chemistry Institute). The coke obtained is tested by methods including technical analysis and determination of the electrical resistivity, the reactivity, and the structural and mechanical strength. In the production of highly reactive coke with high electrical resistivity, the best ore additive is 10–15% manganese-oxide concentrate. The coke is suitable for transportation, transfer, sorting, and crushing to the required size.     

钢铁产业在结构调整、持续发展中与焦化相关若干问题的探讨

针对钢产量在连续快速增长过程中暴露出的结构性、技术性、资源供给与环境保护等方面的问题,对与焦化有关的几个方面进行了探讨。重点讨论了高炉大型化与焦炭质量和炼焦煤资源的关联性、捣固炼焦的焦炭应用、独立焦化企业的限制发展以及完善干法熄焦的安全防护等问题。为今后钢铁产业的健康可持续发展提出了建设性意见。     

浅析焦炭反应性与高炉冶炼

总结了焦炭反应性与高炉冶炼关系的认知历程,阐述了不同反应性焦炭对高炉冶炼过程的影响以及不同反应性焦炭生产的技术手段和研究现状。通过对不同反应性焦炭与高炉冶炼过程适用性的讨论,提出了应根据高炉的冶炼条件和矿石的还原性能来规定适宜的焦炭反应性。     

Utilisation of the binders prepared from coal tar pitch and phenolic resins for the production metallurgical quality briquettes from coke breeze and the study of their high temperature carbonization behaviour

To reduce the cost of the formed coke briquettes which can be used as a substitute fuel to the metallurgical coke for the blast furnace from the coke breeze alternative binders and their blends were used. The high temperature behavior was investigated. The binders tested were: the nitrogen blown, air blown coal tar pitch and the blend of air blown coal tar pitch with the phenolic resins blends. The phenolic resin blends were prepared by mixing equal amount of resole and novalac. From the results, nitrogen blowing resulted in the weakest briquettes. The air blowing procedure should be preferred in place of nitrogen blowing for this purpose. When the air blown coal tar pitch was used alone as a binder, the briquettes must be cured at 200 °C for 2 h, then carbonized at a temperature above 670 °C. Since it requires higher temperature at carbonization stage, using air blown coal tar pitch alone as a binder was not economical. Therefore, the briquettes were prepared from the blended binder, containing air blown coal tar pitch and phenolic resins blend. The optimum amount of air blown coal tar pitch was found to be 50% w/w in the blended binder. Curing the briquettes at 200 °C for 2 h was found to be sufficient for producing strong briquettes with a tensile strength of 50.45 MN/m². When these cured briquettes were carbonized at temperatures 470 °C, 670 °C and 950 °C, their strength were increasing continuously, reaching to 71.85 MN/m² at the carbonization temperature of 950 °C. These briquettes can be used as a substitute for the metallurgical coke after curing; the process might not require un-economical high temperature carbonization stage.     

鞍钢鲅鱼圈7m焦炉焦炭质量评述

鞍钢鲅鱼圈7m焦炉是国内首座开工建设的大型化焦炉,经过1年多的运行,现焦炉运行稳定,焦炭各项质量指标均达到国内焦化行业的先进水平,其焦炭强度指标很好地满足了4000m,大容积高炉的生产要求。文中详述了7m焦炉投产后配煤的优化管理、改善焦炭质量以及保证干熄焦稳定运行的一系列措施。     

A comparative study of by-products yield from coke making processes in a Jenkner apparatus

Physico-chemical characteristics or the industrial behaviour of any coal is directly controlled by its organic micro-components (macerals). The yields of by-products during carbonization of coal are affected by organo micro-components of different coals and operating parameters, such as, charging technologies, carbonization temperature, particle size, bulk density, etc. In the present investigation, the effects of volatile matters (16.61–36.00%), Ro, avg. (0.80–1.36%), exinite (0.5–4.5%), hydrogen (4.34–5.29%) and nitrogen (1.60–2.18%) content of coal on yield of by-products, such as, coke oven gas, coal tar, ammonia, and hydrogen sulphide were studied. The studies revealed that there is a significant difference of the yield of by-products for the two different charging technologies. The coke oven gas, coal tar and ammonia yield was lower in stamp charging process as compared to top charging process, whereas, hydrogen sulphide yield followed a reverse trend.