不同焦煤中硫的赋存形态及热解气体逸出分析

采用XPS方法分别表征了低、中、高硫炼焦煤的硫赋存形态及分布,并利用TG-MS技术分析了三种煤的失重过程、主要气体和含硫气体的逸出情况.结果表明,三种焦煤的硫形态存在明显差异,中高硫煤中的无机硫比例显著高于低硫煤,噻吩类和亚砜类硫比例低于低硫煤.三种煤的失重过程大致相同且可分为释水及吸附气体的脱除、活泼热分解和二次热解三个阶段.焦煤在热解过程中不同含硫气体的逸出差异较大,但其与原煤中原有硫的形态和总量关系密切.     

高硫焦煤和非主炼焦煤在配煤炼焦中的作用研究

鉴于优质焦煤资源短缺,高硫焦煤配煤炼焦备受关注。在实验室模拟炼焦条件下,对山西兑镇和柳林地区7个批次的高硫焦煤的炼焦特性及煤岩组分进行分析,探究高硫焦煤的结焦性能;同时考察了不黏煤、弱黏煤等低黏煤在配煤炼焦中的影响。实验结果显示:与柳林高硫煤相比,兑镇高硫煤单种煤焦的冷强度较高,热强度较低;在配煤炼焦时,兑镇配煤焦的冷强度多数低于柳林配煤焦,但其热强度优于柳林配煤焦,如柳林3配煤焦的M_3为4.02%,M_(13)为94.66%,而CRI*为43.20%,CSR*为69.13%;配入低黏煤可改善焦炭耐磨性和抗碎性,同比例添加条件下,配弱黏煤焦炭质量优于配不黏煤焦炭质量。     

国内高硫焦煤与进口低硫焦煤的优化配用

通过对国内硫分为2%的高硫焦煤指标分析,利用40kg小焦炉试验开展国内高硫焦煤与进口低硫焦煤优化配用研究,并进行6m顶装焦炉工业生产试验。研究表明,国内高硫焦煤通过与进口低硫焦煤优化搭配使用,配比可达到6.5%~8%,配煤成本降低5~10元/t。     

采取合理配煤增加冶炼精煤产量

根据汾西矿区既有高硫焦煤资源又有低硫优质焦煤资源的特点,并结合矿区生产和场地、运输等条件,提出了高硫和低硫冶炼精煤的合理配煤方法以扩大炼焦精煤的产量。     

不同配比长焰煤对高硫焦煤共热解行为及硫迁移的影响

为探究在高硫焦煤中添加长焰煤对煤热解过程及硫形态转化的影响，使用大容量热失重装置考察不同配比长焰煤与高硫焦煤配合的共热解实验，研究了高硫焦煤与长焰煤共热解协同效应；并利用非破坏性光电子能谱（XPS）对热解后的焦炭进行表征，结合煤样的铝甄低温干馏实验，进一步探讨不同配比长焰煤对高硫焦煤中硫形态迁移的影响。结果表明：高硫焦煤中的硫以有机硫为主，其中噻吩类硫质量分数为40%、亚砜类硫质量分数为34%，通过铝甄低温干馏后，87.5%的硫分留在了半焦中，2.8%和9.7%的硫分分别转移至焦油和气体中；不同配比长焰煤与高硫焦煤共热解过程中，在575℃～650℃存在明显的负向协同效应，并且随着长焰煤配比的增加，负向协同效应程度增加；当长焰煤配入质量分数为5%时，能够有效提高脱硫率，促进高硫焦煤中硫化物硫和亚砜类硫的逸出。     

程序升温热解过程中高挥发分煤对高硫焦煤硫迁移的影响

采用程序升温热解方式进行高挥发分煤(Coal B)和高硫焦煤(Coal A)的共热解实验,以期减少焦中硫含量。开展了不同配比实验分析热解过程中硫的迁移,并设计了三组解析对比实验,分析在共热解过程中,发生硫迁移行为的主要影响因素。结果表明,焦煤Coal A含量在50%～66.7%范围时,高挥发分煤Coal B与Coal A的焦反应会降低焦中硫含量。     

低灰中硫焦煤在太钢配煤体系中的研究与应用

为扩大中硫炼焦用煤资源、降低焦炭灰分及配煤成本,太钢开展了配用低灰中硫焦煤的研究及生产实践,利用40 kg焦炉进行低灰中硫焦煤单种煤炼焦试验研究、300 kg焦炉进行配合煤炼焦试验研究,并在7.63 m焦炉进行了低灰中硫焦煤配比为15%工业试验、配比为4%、6%和8%的工业生产。工业生产表明,配用低灰中硫焦煤后,焦炭灰分稳定在12.0%以下,焦炭硫分稳定在0.70%以内,配煤成本降低了2.8元/t。     

高硫煤在炼焦配煤中的应用

我国高硫煤资源丰富,且多为粘结性好的焦、肥煤;为了降低炼焦原料成本,越来越多的焦化厂开始配用高硫焦煤或高硫肥煤进行配煤炼焦。本文结合炼焦工业发展概况,综述了高硫煤在炼焦配煤中的应用进展,以资对合理利用高硫煤配煤炼焦提供参考。     

以低质“特殊和稀缺煤”为主制备高强度冶金焦的研究

中国已将炼焦煤资源中的肥煤(含气肥煤)、焦煤(含1/3焦煤)、瘦煤规定为"特殊和稀缺煤"。通过研究低质"特殊和稀缺煤"之间的配伍性,合理搭配该类煤,在优质"特殊和稀缺煤"焦煤、肥煤配入比例降至3%,无高变质程度炼焦煤的情况下,制备出高强度冶金焦。     

2种改善型煤种的配煤炼焦试验研究

对柳林高硫焦煤和俄罗斯肥煤2种改善型煤种煤质进行分析,并分别对比同类常用炼焦煤,结果表明,柳林高硫焦煤和俄罗斯肥煤均为单一煤种,属于优质炼焦煤,具有较高的G值、Y值,可以作为配煤炼焦的基础煤种。20 kg小焦炉炼焦试验结果表明,2种改善型煤种单种煤所得焦炭质量较好,与其他煤种均有较好的配伍性。工业单独配用后焦炭质量的对比表明,2种改善型煤种可改善焦炭质量,降低企业配煤成本。     

Molecular components of coal and coal structure

A high-volatile bituminous coal was extracted at room temperature by various organic solvents. The yields of the extracts ranged from 4.5 wt% daf (ethanol/benzene extract) to 38 wt% daf (pyridine/ethylenediamine extract). The extracts were analysed by Fl mass spectrometry; the volatile part (75–80 wt%) was composed of substances of molecular weight in the range 70–800 amu, but the compounds in the 200–600 amu range predominated. Over 300 compounds were identified by high-resolution mass spectrometry. The results indicate that compounds < 800 amu constitute at least 30 wt% daf of the analysed coal.     

Differences between mineral coal and extracted coal

A distinction is proposed between mineral coal and extracted coal. Mineral coal is a complex natural composite that is found in underground beds, while extracted coal is created from mineral coal in working those beds. It is important to keep in mind that mineral coal is created by natural processes, whereas extracted coal is produced by human activity.     

Electrical conductivity of coal and coal char

The electrical conductivity of coal, at either 1 kHz or d.c., was measured at 24 °C on samples recovered from pyrolysis experiments aimed at modelling conditions during in situ gasification of coal. From an initial value of 10⁻³ S/m (when the coal is saturated with formation water), the conductivity decreases to 10⁻⁸ S/m when the coal is heated to 110 °C in vacuum. This low value, presumably due to dehydration of the coal, prevails for samples heated as high as 500 °C in dry argon. Samples of char recovered after pyrolysis to 800 °C or more have a conductivity of 10² S/m. Capitalizing on the large contrast between the conductivities of coal and char produced during gasification, electrical probing may be a sensitive tool for monitoring ‘burn-front’ progress during in situ coal gasification.     

澳大利亚煤代替西曲焦煤的配煤炼焦研究

对澳大利亚煤和国内6种单种煤进行煤质分析和配煤炼焦实验,分析澳大利亚煤代替西曲煤进行炼焦的可行性。结果表明澳大利亚煤具有低灰低硫、高挥发分等特点,在炼焦中用澳大利亚煤替代西曲焦煤可降低焦炭的灰分和硫分,增大焦炭的各向异性指数,改善焦炭强度。     

Industrial coking of coal batch without bituminous coal

For many years, Kuznetsk-coal batch has always included bituminous coal. Depending on the content of such coal, the batch may be characterized as lean, moderately clinkering, or bituminous. This classification was adopted by specialists of the Eastern Coal-Chemistry Institute (ECCI) in experimental coking at Magnitogorsk Metallurgical Works in 1945 [1]. Lean batch contained 10% Osinovsk bituminous coal (plastic-layer thickness y = 13 mm); moderately coking coal contained 25% bituminous coal (y = 16 mm); and bituminous batch contained 40% of such coal (y = 20 mm).     

黏结煤与不黏煤共热解特性研究

为了利用内构件反应器热解技术实现黏结性煤的高值化利用,采用TG-MS和固定床反应器研究了黏结的山西兴县煤(简称XX煤)与不黏的先锋褐煤(简称XF煤)共热解时的破黏和热解特性。TG-MS实验结果表明,XX煤与XF煤配制的混合煤比XX煤黏性小,且XF煤促进了XX煤热解,混合煤热解行为是两种煤共同作用的结果。固定床热解实验表明,煤粒径越小,降黏越显著;XX煤和XF煤的比例(XX:XF)越小,降黏越显著,XX:XF小于5:5时,可消除结焦团块;XX:XF越小,半焦产率越低,焦油和煤气产率越高;随XX:XF减小,焦油中<170℃和230~300℃的馏分含量先升后降,XX:XF=6:4~3:7时最高,170~210℃、210~230℃和300~360℃的馏分逐渐增加,>360℃的馏分含量不断降低;随XX:XF的减小,H2含量先升高后降低,在XX:XF=3:7时最高;CO含量呈略微升高趋势;CO2含量先逐步升高,在XX:XF=6:4达到最高,然后从XX:XF=5:5开始降低,在XX:XF=3:7达到最低,然后又开始升高;CH4及C2~C3组分含量呈下降趋势,而H2+CO+CH4 (煤气中有效组分之和)的含量先下降再升高接着再降低,在XX:XF=6:4时最低,XX:XF=3:7时最高。XX:XF越小,虽半焦的C/N和C/H不断减少,但C元素含量增幅和N, H元素含量减幅增大;比表面积越大,内孔结构越多越大,起燃温度越低,燃烧越彻底。     

关于混煤的配煤探讨

针对生产用煤多为复杂混煤的不利情况,在常规分析数据的基础上利用岩相分析手段指导配煤,有效稳定了焦炭质量,明显改善了焦炭的热态性能。     

煤岩学在炼焦配煤中的应用进展及优化配煤技术

科学合理的配煤技术对于焦化企业高质量发展至关重要,炼焦配煤技术的核心在于对原料煤煤质特性的深入认知。影响炼焦煤性质的主要因素包括变质程度、煤岩组成及第三成因因素,故煤岩学对炼焦配煤技术的研究与应用至关重要。本文论述了经验配煤、煤岩配煤及人工智能配煤3种炼焦配煤技术发展历程和现状,凝练了炼焦配煤技术的发展趋势。结合研究实际,重点梳理了煤岩学指标在炼焦配煤中的应用现状。在注重煤岩特征的同时,也需兼顾工艺指标等相关参数对炼焦煤优劣的表征。在实际应用中,各项指标参数的选择和利用需要综合考虑参数适配范围并尊重该指标与炼焦煤特性的真实对应关系。基于以上内容,提出了关联成煤时代、产地等地质因素和黏结指数、胶质层指数等工艺指标的整体思路,实现焦炭性能与原料煤特性的科学、深入关联,构建“本源-过程-结果”一体的优化配煤技术新体系。     

Coking properties of coal pitch in coal batch

The coking properties of coal pitch depend significantly on its fractional composition, which determines the set of structural components involved in meso-phase formation. The optimal combination of high-molecular aromatic compounds, polycyclic compounds of intermediate molecular mass, and hydrogen-donor hydroaromatic components corresponds to a ratio of pitch fractions α: β: γ = 1: 2: 2. This is typical of coal pitch with a softening temperature of 75–85°C. Such pitch is the best clinkering additive to coking batch, resulting in the production of coke of maximum strength.