焦炭强度与热性质控制因素分析

在20kg小焦记上进行了11种单种煤和8种配煤方案的炼焦试验,建立了焦炭质量预测模型。结果表明,单一的煤质指标与焦炭强度的关系不明显,多因素指标进行焦炭质量的预测效果较好;焦炭反应性与单一煤质指标中Vd、^—Rmax^0、Ad之间有较好的关系,且随反应温度的升高而增大。     

焦炭强度与煤质指标

本文研究了32种单种煤样的焦炭强度和六种煤质指标之间的关系。结果表明,粘结指数G能较好地反映焦炭强度的变化,煤的岩相分析与煤的粘结性指标组合的二次幂式能较好地预测焦炭抗碎强度M40或耐磨强度M10。单一煤分析指标反映焦炭强度变化的能力较差。     

炼焦强黏煤对焦炭热强度影响研究

为研究炼焦强黏煤对焦炭热性质的影响,利用试验焦炉(SCO)对梅山常用11种单种强黏煤进行了炼焦实验及焦炭反应性实验.结果表明,炼焦强黏结煤的黏结性、变质程度和碱度指数是对焦炭热强度的关键影响因素,使用黏结性适中、变质程度适中或碱度指数较低的强黏煤都可以得到热性质较好的焦炭,控制焦炭热强度的关键在于单种煤质量.     

焦炭抗拉强度的研究

研究了单种煤焦炭抗拉强度与煤的 Rmax、Vdaf、G之间的关系 ,发现它们之间均呈现很好的曲线关系(中等变质程度的煤所得的焦炭抗拉强度高 ) ;且单种煤焦炭的抗拉强度与焦炭的结构强度 ,显微强度测定值之间存在有较好的相关关系 ;还研究了抗拉强度与气化量之间的关系 ,结果表明也存在良好的线性关系。     

焦炭质量预测方法的应用

以太原煤炭气化(集团)有限责任公司的工业焦炉数据为基础,建立了该公司的焦炭质量预测模型。利用单种煤和配合煤的各种性质指标预测焦炭质量,并指导配煤,以获得稳定的焦炭质量。     

炼焦煤的煤岩特征对焦炭质量的影响

先选用某钢厂3种不同变质程度的生产用煤,对这3种单种煤进行了工业分析和煤质分析,并以此为基础,确定了3种配煤方案,得到3种配合煤。采用6个煤样进行40 kg捣固焦炉炼焦实验,对所得焦样进行性能检测,并分析了煤岩显微组分与焦炭冷热强度的关系,结果表明,煤岩显微特征对焦炭的性能影响较大,可以指导生产配煤。     

北美焦煤和肥煤的配煤炼焦研究与实践

为缓解低灰、低硫焦煤与肥煤资源紧张现状,稳定焦炭生产,公司引进了北美焦煤与肥煤。通过开展单种煤煤质与炼焦特性、配煤炼焦试验研究,分析了配合煤煤质与焦炭质量的相关性关系。结果表明：北美焦煤与肥煤具有低灰、低硫的优质特性,但其热性质相对国内同类煤种差,其参与的配煤结构中配合煤的挥发分、黏结指数及灰成分指标,均与焦炭的机械强度、热性质具有较高的线性拟合度,均大于0.80。通过优化配煤结构,在7m顶装焦炉中应用北美焦煤或肥煤的比例可达8%～12%,并可稳定生产出CSR约为67.5%与CSR约为70%的合格焦炭。     

坩埚焦性质的研究

研究了单种煤、工业配煤坩埚焦炭与20kg试验炉焦炭的反应性、反应后强度、结构强度、显微强度及配合煤焦炭的光学组织指数间的关系,结果表明,它们之间有良好的相关关系。     

用镜质组反射率分布控制水钢焦炭质量的研究

采用煤镜质组反射率分布并结合常规煤质指标,对稳定和控制水钢焦炭质量进行了实验研究.对水钢的18个煤样进行了反射率及常规指标的检测、煤质分析与评价和炼焦实验;对水钢的生产方案及建议方案进行了40 kg焦炉炼焦实验,并对其进行了分析;使用煤镜质组反射率分布并结合常规煤质指标为水钢制定了三个优化配煤方案,焦炭质量提高,完全满足生产要求.研究结果表明,煤镜质组反射率分布图是指导炼焦配煤的有效手段,对稳定和控制焦炭的热性质效果十分明显,对炼焦配煤煤种多和有混煤情况尤其适用和有效.     

基氏流动度在配煤炼焦中的应用

针对迁安中化炼焦煤采用常规煤质指标分析出现的单种煤常规指标较好,配煤炼焦后焦炭强度下降的问题,采用基氏流动度分析了常用两种中强黏结性炼焦煤A煤和B煤的煤质,探讨了其与常规煤质指标的关系,介绍了基氏流动度在配煤炼焦中的应用情况及存在问题。结果发现,A煤和B煤的常规煤质指标接近,最大基氏流动度分别为7209 ddpm和829 ddpm,可以较好区分两种煤;基氏流动度特征指标中的软化温度、塑性温度区间及最大流动度可反映炼焦煤的基本性质;炼焦煤的最大流动度的对数值在2.2~3.0、挥发分在23%~27%时,焦炭M40>87%、M10<7%。     

An approach to blast furnace coke quality prediction

Although coke cold drum mechanical strength has historically been the most relevant coke quality parameter, currently coke reactivity and post-reaction strength (CRI/CSR) are the most important parameters used to assess blast-furnace coke quality. Many models of coke quality prediction have been proposed, most of which are based on coal characteristics and limited to the same coal geographic origin, but as yet there is no universally applicable prediction formula. The present work describes a simple model of coke CRI/CSR prediction based on the assumption that the CSR of a coke produced from a blend of coals can be predicted from the CSR obtained from the cokes of the individual coals through the application of the additivity law. The additivity law was also applied to the coke cold mechanical strength indices derived from the Irsid test, which are widely employed by the European coke industry as complementary coke quality indicators.     

Correspondence between the composition and plastic properties of British coals and the structural properties and reactivity of the corresponding cokes

The chemical composition and the physico-chemical properties of a suite of British coals, mainly of types 501/2 as defined by the NCB classification, but including some coals of higher and lower rank (NCB classification 204,401/2 and 601/2), were comprehensively investigated. Each coal was subsequently carbonized under controlled conditions of size distribution, bulk density and temperature on the 250 kg scale and the tensile strength, coke structure and coke reactivity were determined. This data highlighted the significance of the atomic ratio of the oxygen and carbon of the coals and the lack of relations between coal properties and coke structure and strength. As regards coke reactivity only complex relations with coal properties could be found, with coal rank, the oxygen/carbon ratio and the chlorine content being of greatest importance.     

Modification of sub-bituminous coal by steam treatment: Caking and coking properties

A Chinese sub-bituminous Shenfu (SF) coal was steam treated under atmospheric pressure and the caking and coking properties of the treated coals were evaluated by caking indexes (G_RI) and crucible coking characterizations. The results show that steam treatment can obviously increase the G_RI of SF coal. When the steam treated coals were used in the coal blends instead of SF raw coal, the micro-strength index (MSI) and particle coke strength after reaction (PSR) of the coke increased, and particle coke reactivity index (PRI) decreased, which are beneficial for metallurgical coke to increase the gas permeability in blast furnace. The quality of the coke obtained from 8% of 200 °C steam treated SF coal in coal blends gets to that of the coke obtained from the standard coal blends, in which there was no SF coal addition in the coal blends. The removal of oxygen groups, especially hydroxyl group thus favoring the breakage of the coal macromolecules and allowing the treated coal formation of much more amount of hydrocarbons, may be responsible for the modified results. The mechanism of the steam treatment was proposed based on the elemental analysis, thermo gravimetric (TG) and FTIR spectrometer characterizations of the steam treated coal.     

Impact of low-cost filler material on coke quality

An investigation was made to study the influence of low-cost filler material such as non-coking coals and refuse-derived fuel (RDF) on coke quality. Interfaces between textural components within the cokes were successfully characterised and the derived interface quality index showed some cokes contained more ‘good’ quality interfaces than others. The addition of filler coals and RDF to the coking coal increased the proportion of ‘poor’ interfaces’. A good correlation between coke strength, derived from a small drum test, and interface quality index was observed. During heat treatment of cokes at 1600 °C both metallic and non-metallic micro-constituents were found to undergo some transformation as revealed by the SEM surface morphology examination. Although heat treatment caused some fractures to enlarge and others to emerge, its effect on the quality of the coke was not significant. Based on the results from the samples studied, there were some indications of the potential use of RDF material in the production of coke as there were minimal adverse effects on the quality of coke produced.     

气肥煤替代部分肥煤进行捣固炼焦试验研究

通过气肥煤、肥煤与其他单种煤的共结焦试验，考察了二者的改质作用，试验结果证明肥煤改质作用优于气肥煤。在此基础上进行了气肥煤替代部分肥煤的捣固炼焦试验，结果表明在保持配合煤黏结性稳定的前提下，焦炭的反应后强度随着气肥煤替代量的增加先增大后减小，焦炭反应性的变化趋势与之相反，而焦炭的冷态强度随着气肥煤替代量的增加变化不大。     

Coke reactivity: Effect of Fe2O3 and K2CO3 addition to the coal charge before carbonization

Six individual coals and one blended metallurgical coal were used in this investigation, and two additives, Fe₂O₃ (up to 1%) and K₂CO₃ (0.5%), were added to each coal before carbonization. Results showed that the additives strongly increase CRI (coke reactivity index) and decrease CSR (coke strength after reaction) of each coke, but there are no significant changes in coke microstructure.     

单种煤性质对其焦炭性质的影响

通过测定11种单种煤和所炼坩埚焦的性质，得出单种煤挥发分与平均最大反射率在合适的范围内，所炼坩埚焦的反应性最小，结构强度最大。     

Influence of coal forced oxidation on technological properties of cokes produced at laboratory scale

The effect of coal oxidation in air at 140 °C on the technological properties of cokes obtained at laboratory scale from two medium volatile bituminous coals has been studied. The proximate and ultimate analyses do not show important changes with coal oxidation time. However oxidation clearly has a strong effect on the plastic properties of the coals in view of the fact that the Gieseler fluidity eventually disappears. From this point variations in plastic properties can still be detected by FSI. Other changes, such as a shortening of the length of the saturated fragments of the aliphatic chains, a decrease in the aliphatic hydrogen content and an increase in the oxygen-containing groups are detected by PA-FTIR. It was also found that the main coke quality indices (mechanical strength and reactivity to CO₂) of both coke series are impaired with coal oxidation. A close relationship between reactivity to CO₂ and the micropore specific surface area of the cokes has been corroborated.