进口蒙古国煤炭中有害微量元素的含量分布及赋存形态

为评估进口煤对国内环境的影响,采用原子荧光光谱、直接测汞仪、离子色谱、电位滴定等对360批蒙古国煤炭中的灰分、硫、汞、砷、氟、氯、磷含量进行了测定,用稳健统计等方法描述了7项指标的整体水平,并根据我国煤炭相关分级标准和富集系数进行了评价。蒙古国煤炭总体为特低汞、特低氯、低灰、低硫、中氟、中砷、中磷煤,砷的平均富集系数均为16,其环境迁入风险值得关注。利用相关分析与聚类分析推断了硫、汞、砷、氟、氯、磷的赋存形态,360批蒙古国煤炭可分为三大类,可能存在3种不同的矿脉来源,具有不同的特征。综合考虑相关分析与因子分析结果,主因子特征可描述为有机态砷伴生矿物因子、含氟矿物(氟磷灰石和硅铝酸盐)因子和硫因子。     

铁法矿区煤的基本特征及其微量元素

系统地研究了东北地区最大的动力煤供应基地铁法矿区长焰煤的资源、性质及其有益、有害微量元素的分布。发现铁法煤中的硫、磷、砷、氯等有害元素及铅、铬、汞等重金属元素的含量均较低,是辽宁省内主要燃煤电厂的重要优质煤源。     

山西煤用于干粉气流床气化的煤质适应性研究

与气化炉匹配的煤质条件会保证气化炉的平稳运行,提高气化炉的气化效率。为提高干粉气流床气化炉的气化效率,本文结合干粉气流床气化用煤的技术要求及煤炭质量分级等相关标准,对山西大同煤田的弱黏煤和沁水煤田的贫煤、无烟煤的煤质特征进行分析评价,开展山西煤用于干粉气流床气化的煤质适应性研究。结果表明:山西地区煤种丰富,其中可气化用煤主要分布在大同煤田和沁水煤田。地处大同煤田的虎龙沟煤、小峪煤和地处沁水煤田的润东煤的灰分较高,干基灰分分别为31. 81%、35. 59%和42. 17%;煤气化时煤中硫主要以H_2S形式存在于煤气中,小部分残存于灰渣中,含硫化合物会腐蚀煤气运输管道,大同煤田金庄煤的全硫含量较高,干基全硫高达2. 10%;从煤炭有害元素含量分级来看,山西气化用煤的氟、氯、砷、汞和磷含量普遍较低,但润东煤的氟含量较高,干基氟含量高达235μg/g,煤炭气化过程中,高温下煤中氟分解为HF及少量Si F4、CF4等进入煤气中,因此有必要在气化前通过分选达到降灰、降硫和降氟的目的。山西气化用煤大多为中高灰熔融性温度煤,润东煤ST为1 340℃,其余煤的ST、FT均大于1 500℃。煤灰黏温特性试验结果表明,灰黏度为25 Pa·s时,虎龙沟煤灰对应的温度为1 445℃,小峪煤、同忻煤和塔山煤灰对应温度分别为1 630、1 645和1 605℃。从灰渣形态看,虎龙沟煤的灰渣形态为玻璃渣,小峪煤、同忻煤和塔山煤的灰渣形态为结晶渣,用于气流床气化时可能导致温度操作区间范围窄,因此建议采用通过添加助熔剂、配煤或分选手段达到改善熔渣渣型的目的。     

宝日希勒露天煤矿煤层煤质特征及洁净等级划分

为合理清洁利用内蒙古自治区陈旗煤田宝日希勒露天煤矿的煤,基于全区地质背景以及大磨拐河组含煤地层的基本情况,对矿区煤的物理性质与煤岩特性进行了分析,确定煤的工业性能和用途,选取灰分、硫分,有害元素砷、氯等4个评价因子对矿区煤的洁净等级进行初步划分。结果表明:12、21、31、32+3煤层的宏观煤岩类型多为暗煤及半暗型煤;有机显微煤岩类型以腐植组和惰质组为主。原煤属低灰、高挥发分、中高固定碳、特低硫、特低氯、特低~低磷、一级含砷煤。通过分析原煤工艺性能,说明煤层以褐煤二号为主,属中高发热量、焦油产率较高、中等结渣煤,其中21煤为易磨煤,12及31煤为极易磨煤、极难选煤。矿区总体煤洁净等级为Ⅱ级,属好洁净煤。     

固体生物质燃料棕榈壳基本特性研究

棕榈壳作为棕榈油产业的废弃物,资源十分丰富。文章对固体生物质燃料棕榈壳的工业分析、燃烧特性和化学特性做了比较全面地分析研究。结果表明:棕榈壳有着高发热量、高挥发、低灰分、低全硫含量和低有害元素砷、磷、氟、氯和汞等含量等优异特性。是一种非常良好的环保固体生物质燃料。     

太原西山煤田煤系锂镓赋存特征及工业前景

为研究太原西山煤田中锂镓元素的赋存特征及其工业边界品位,分析了西山煤田煤系地层锂镓分布特征和决定因素,讨论了煤和煤矸石锂、镓含量与Al_2O_3、高岭石、粒度的关系,并分析了西山煤田煤系锂镓的内蕴资源量和工业前景。研究认为,西山煤田煤中锂含量高于与全国煤中锂的平均值,煤中镓含量大于山西煤中镓平均值,但均小于煤中锂、镓的建议回收指标。煤层夹矸中锂、镓含量显著高于煤层,且大于煤中锂、镓的边界品位。垂向上,山西组煤的镓含量高于太原组。西山煤田煤中锂、镓和煤中Al_2O_3含量呈正相关关系,且较多地赋存于粗颗粒夹矸中,而在细颗粒夹矸中含量较少。夹矸中镓含量和高岭石含量呈正相关关系,但锂含量和高岭石关系不明显。西山煤田煤系地层锂、镓的内蕴资源量分别为2.39万t和7.10万t,在目前经济技术条件下,西山煤田煤中锂不具有工业开发价值,古交邢家社矿区山西组下部煤层和马兰矿区8号煤夹矸中镓接近煤和夹矸中镓的边界品位,具有潜在的工业价值。     

田庄选煤厂分选产品燃烧过程中汞的释放规律

通常煤中含有0.1×10-6～0.15×10-6的汞,在燃烧和气化过程中被排放到空气中.由于其高挥发性和毒性,特别是会对神经系统造成影响,所以成为人们关注的一种重要的重金属元素.对河南省田庄选煤厂的一种T煤进行了分选,根据分选产品的TGA和DTG曲线分析了煤样的燃烧特性,通过对不同温度段元素汞和氧化态汞的采集和测定,研究了不同分选产品的汞释放行为.结果表明,末原煤、末中煤和末精煤具有相似的燃烧和汞释放行为.烟气中元素汞的含量大于氧化态汞的含量.通过物理分选,煤样中部分无机汞可以被富集到重产品中.     

陕西原煤中的氟含量及空间分布

对陕西6大产煤区中64个煤矿进行采样、分析,得到陕西原煤中氟含量及其空间分布特征,陕西原煤中氟含量的几何平均值为84 mg/kg;陕西原煤中氟含量的空间分布差异不大,南部地区煤中氟含量比北部地区煤中氟含量高;按照成煤时代划分,陕西原煤中氟含量由高到低依次为陕南煤田渭北石炭二叠纪煤田陕北石炭二叠纪煤田陕北三叠纪煤田黄陇侏罗纪煤田陕北侏罗纪煤田。     

元宝山露天煤矿煤层煤质特征及洁净等级划分

为了合理清洁利用元宝山露天煤矿的煤,基于元宝山露天煤矿地质概况、含煤地层特征及煤的物化性质,对矿区煤的煤质特征进行工业分析,确定煤的类型、工业性能和用途,根据最新煤炭资源潜力评价提出的煤炭洁净等级6级划分方案,选取灰分、硫分、有害元素氟、砷等4个评价因子对矿区煤的洁净等级进行初步划分。结果表明:矿区煤的宏观煤岩组分以亮煤和暗煤为主,显微煤岩组分以镜质组为主;矿区煤属低灰、中硫、高挥发分、中发热量型的2号褐煤;矿区主要煤层5煤、6煤洁净等级为Ⅲ~Ⅳ级,属较好~中等洁净煤,总体煤洁净等级为Ⅳ级,属中等洁净煤。由于矿区煤为中发热量、热稳定性较差,且与CO_2化学反应性好、焦油产率较高、中等洁净的煤样,煤炭质量和洁净等级较好,可作为动力用煤、气化用煤和炼油用煤原料,经济价值较大。     

低阶煤筛分过程中汞及硫元素在不同粒度中的分布规律

燃煤是大气汞污染的主要排放源之一,针对目前煤炭洗选过程中重金属元素迁移脱除研究的不足,选用内蒙古低阶高硫煤和低硫煤样进行筛分试验,通过测汞仪、化学逐级提取、X射线衍射（XRD）、X射线荧光分析（XRF）及扫描电镜等测试方法研究汞元素在煤中的赋存形式及在不同粒度级煤中分布规律。试验结果表明,汞元素在煤中的分布不仅和赋存形式相关,还与矿物质在煤中的组成形式和矿物本身的矿物学性质相关。由逐级化学提取可知,高硫煤与低硫煤中汞主要以二硫化物结合态存在。两种煤中的汞和硫在不同粒度区间的富集和迁移趋势一致;高硫煤中汞含量与灰分在6～13mm粒度区间均为最高,说明汞主要与此粒度区间密度较大的黄铁矿伴生;低硫煤在粒度<0.074mm区域内,灰分及汞的含量较高,因为部分汞在以黏土矿为主的小颗粒中富集。     

煤矸石中汞、砷的研究进展

煤矿生产过程中伴生的大量煤矸石不仅占用土地资源,而且在露天堆放的过程中其含有的有害微量元素汞、砷等会进入自然环境中,对环境造成严重污染。通过总结,介绍了国内外学者对于煤矸石中汞、砷的研究成果。主要从煤矸石中汞、砷含量,煤矸石加热汞、砷释放,煤矸石中汞、砷淋溶析出以及煤矸石中汞、砷赋存形态四个方面进行总结。以期为更多学者对于煤矸石中汞、砷的研究工作提供一定的帮助。     

烧结烟气脱硫制酸净化工序的设计与生产实践

介绍了太原钢铁（集团）有限公司炼铁厂烧结机烟气活性炭干法脱硫富集SO_2烟气的组分和工况。该富集SO_2烟气流量小、温度高、高含硫、高含尘并含有氨、氟、氯、汞等有害杂质,设计采用喷淋塔一一级泡沫柱洗涤器—气体冷却塔—二级泡沫柱洗涤器—两级电除雾器稀酸洗工艺加以处理,并对净化设备进行了设计选型。炼铁厂450m~烧结机烟气脱硫制酸装置已稳定运行1年多时间,净化工序各项指标均达到或超过设计值,较好地解决了恶劣工况烧结烟气净化除杂问题,净化收率达到99.01%,净化工序出口烟气尘（ρ）1.4mg/m~3,硫酸雾、HF、HCl、NH_3等微量。     

煤矸石中氟的赋存特性及生态风险评价

为确定陕西韩城矿区和黄陵矿区煤矸石中氟的赋存特征及潜在生态风险,以韩城石炭-二叠纪煤矸石和黄陵侏罗纪煤矸石为研究对象,对两地煤矸石中6种形态的氟化物进行连续分级提取,使用分光光度计测定含量.结果表明:韩城矿区和黄陵矿区煤矸石中氟赋存形态以次生相(水溶态、离子交换态、无定形铁铝结合态、结晶铁铝结合态和有机结合态)为主,质...     

Volatilization of mercury,arsenic and selenium during underground coal gasification

Mercury, arsenic and selenium are trace elements well-known for their high volatility in underground coal gasification (UCG) which can lead to environmental and technical problems during gas utilization. In this paper, the volatilization of mercury, arsenic and selenium from coal in a seam during the process of UCG were investigated, based on comparison of their volatility during the transformation of coal to char and the conversion of char to ash. Three types of coal were involved in this study. The results indicate that the volatility of mercury, arsenic and selenium during UCG in the seam follows the sequence of Hg>Se>As. Mercury and selenium show volatility higher than 90% from coal to ash. The volatility of arsenic is lower than 60% as confirmed by arsenic enrichment in UCG ash. Arsenic volatilization during UCG is also enhanced by increasing temperature, which is different from the result during the combustion of crushed coal. Coal type has obvious effect on element volatilization. The higher the coal reactivity, the easier is the evaporation of the elements from coal in the seam. At the same time, thermodynamic equilibrium calculations using MTDATA program were performed to predict the possible species in UCG gas. With regard to UCG gas at the production well, mercury presents as Hg(g), H₂Se(g) is the main gaseous species of selenium, whereas arsenic occurs in condensed phase as As₂S₃ and As. The effect of the pressure on the equilibrium composition of the gas results in major changes of the proportions of the species. High pressure leads to the formation and enhancement of the reduced species and increases the condensation temperature of the volatile elements.     

焦作矿区深部煤层赋存及煤岩煤质特征

分析了焦作矿区构造特征和底层分布,说明焦作矿区属典型的华北石炭-二叠系含煤地层,内断层非常发育,多为北东向、近东西向和北西向的正断层。通过对矿区地质分层及目标煤层赋存情况的研究,说明焦作矿区主煤层山西组二1煤层厚度大,分布稳定,属结构简单型煤层;地层自上而下分别为第四系、第三系、上二叠统上石盒子组、下二叠统下石盒子组、山西组及上石炭统太原组。最后对二1煤层煤岩煤质特征进行了分析,结果表明:山西组二1煤属高变质程度无烟煤,宏观煤岩特征为灰黑色,似金属光泽,半暗型,以暗煤为主,亮煤次之,棕色条纹,质轻、污手,块煤为参差状断口,煤芯呈块状、粉状及颗粒状,粒径0.1～1.0 cm。     

彬长矿区4号煤层煤质特征及洁净等级划分

为实现彬长矿区优质煤炭资源的清洁高效利用,在对彬长矿区以往勘查钻孔的煤质化验资料统计分析的基础上,系统分析了该矿区主采煤层4号煤的煤岩、煤质特征,论述了硫分、灰分、挥发分、发热量和有害微量元素的分布规律,依据最新煤炭资源潜力评价提出的煤炭洁净等级6级划分方案,选用灰分、硫分、有害元素(F、Cl、As及Pb)6个评价指标对矿区内4号煤层的煤炭资源洁净等级进行了初步划分。彬长矿区4号煤层以低硫、低中灰、中高挥发分、特高热值不黏煤为主,局部含小范围的弱黏煤,彬长矿区4号煤层原煤洁净等级为Ⅲ级,属较好洁净煤;浮煤洁净等级为Ⅱ级,属好洁净煤。整个矿区内4号煤层原煤洁净等级以Ⅲ级较好洁净煤为主,分布区占矿区面积的73.03%,仅在矿区西部洪家镇—巨家镇一带和中东部出现小范围的Ⅳ级中等洁净煤分布区,面积占比为26.97%。     

Distribution of potentially hazardous trace elements in coals from Shanxi province, China

Shanxi province, located in the center of China, is the biggest coal base of China. There are five coal-forming periods in Shanxi province: Late Carboniferous (Taiyuan Formation), Early Permian (Shanxi Formation), Middle Jurassic (Datong Formation), Tertiary (Taxigou Formation), and Quaternary. Hundred and ten coal samples and a peat sample from Shanxi province were collected and the contents of 20 potentially hazardous trace elements (PHTEs) (As, B, Ba, Cd, Cl, Co, Cr, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se, Th, U, V and Zn) in these samples were determined by instrumental neutron activation analysis, atomic absorption spectrometry, cold-vapor atomic absorption spectrometry, ion chromatography spectrometry, and wet chemical analysis. The result shows that the brown coals are enriched in As, Ba, Cd, Cr, Cu, F and Zn compared with the bituminous coals and anthracite, whereas the bituminous coals are enriched in B, Cl, Hg, and the anthracite is enriched in Cl, Hg, U and V. A comparison with world averages and crustal abundances (Clarke values) shows that the Quaternary peat is highly enriched in As and Mo, Tertiary brown coals are highly enriched in Cd, Middle Jurassic coals, Early Permian coals and Late Carboniferous coals are enriched in Hg. According to the coal ranks, the bituminous coals are highly enriched in Hg, whereas Cd, F and Th show low enrichments, and the anthracite is also highly enriched in Hg and low enrichment in Th. The concentrations of Cd, F, Hg and Th in Shanxi coals are more than world arithmetic means of concentrations for the corresponding elements. Comparing with the United States coals, Shanxi coals show higher concentrations of Cd, Hg, Pb, Se and Th. Most of Shanxi coals contain lower concentrations of PHTEs.     

Study on the fate of As,Hg and Pb in Yima coal via sub-critical water extraction

Arsenic, lead and mercury are the major hazardous trace elements contained in coals. During coal combustion these trace elements release and emit to the atmosphere and cause harmful effects to the human beings and the environment. This paper is to study the fate of arsenic, lead and mercury in Chinese Yima coal by sub-critical water treatment. The experiments were performed in a semi-continuous apparatus. Demineralization, float-sink experiment and sequential chemical extraction were carried out in order to examine the transformation of occurrence mode of the three elements. The results show that with increasing temperature and residence time, the removal of As, Pb and Hg increases. At 410 °C, 15 MPa, 30 min, with water flow rate of 450 ml/h, the removal of mercury and arsenic is about 100% and 57%, respectively. It is difficult to remove lead by sub-critical water extraction. Arsenic and lead in Yima coal are associated not only with pyrite, but also with monosulfides and sulfates, other minerals including silicates, aluminum silicates etc. and organic matters. Mercury is mainly associated with pyrite (about 75%) by adsorption, and is also associated with other minerals such as clays, silicates, aluminum silicates etc. During sub-critical water treatment, arsenic associated with carbonates, sulfates and monosulfide, pyrite and other minerals all decrease, and that associated with organic matters increase. Only a little lead in Yima coal is removed by this process. Mercury associated with pyrite and other minerals decreases, and that associated with sulfates and monosulfides disappears after sub-critical water extraction.     

用于混煤燃烧控制砷排放模型研究

混煤掺烧是控制燃煤砷排放的有效方式,但由于缺乏相关的配煤模型,限制了该技术的应用。根据燃煤过程中砷的挥发释放机制,提出一种采用砷的释放指数P表征煤燃烧过程砷的释放特性的配煤模型。该模型综合考虑煤的灰分、灰中主要矿物元素含量、各矿物元素对砷的固定系数以及煤中砷含量等因素。研究结果表明,随着煤灰固定系数由23.12增至50.90,煤灰的气相砷吸附量由3.39 mg/g增至6.14 mg/g;随着释放指数P增大,砷的固定率减小,且随着温度升高,两者相关性由900℃的0.67增至1 300℃的0.86。根据P值筛选煤种进行掺烧,当掺混煤种P值差异较大时,掺烧低P值煤种不仅可降低混煤中的砷含量,还能促进高P值煤的砷在灰中富集,促进率达77.14%;掺混煤种P值差异较小时,掺烧低P值煤种会促进砷的释放。本模型可较好地筛选煤种,为混煤掺烧控制砷等痕量元素的排放提供了新的思路。