褐煤全周期利用经济性分析

针对我国目前褐煤利用现状,分析了褐煤利用领域存在的盲目性和无序性,以褐煤的全生命周期为对象,通过掺烧试验方法分析了电站锅炉掺烧褐煤的经济性,结合褐煤提质工艺不同对褐煤加工成本的影响,建立了褐煤全生命周期利用模型,指出该模型的主要用途和使用条件,为褐煤的加工利用提供了经济效益的数学评价方法。结果表明,采用提质后的褐煤作为电站锅炉燃料,电站锅炉效率和经济性明显好于未经提质的褐煤,运输成本也较低,但褐煤提质过程也要消耗资源,需按照全生命周期利用经济模型综合比较后决定。     

过程的景观

<正>德国东部劳西茨(Lausitz)地区蕴含着丰富的褐煤资源，百余年来对褐煤的开采严重破坏了区域的地貌和植被，污染了土壤和地下水。我曾于1995年到访过那里，当时褐煤开采已基本停止，留下的是望不见尽头如月球表面般的荒芜大地和数十处巨大的露天采煤坑。废弃的采煤设备、东倒西歪的工房和遗弃的破旧汽车更让这片土地尽显萧瑟与凋敝。     

二连盆地褐煤断裂行为加载率效应及对压裂裂缝调控的启示

室内试验尺度对煤岩断裂行为及加载率效应的认识同样有助于地下储层压裂过程中压裂裂缝延展规律分析及压裂造缝形式的调控。利用SHPB试验对采取自内蒙古二连盆地褐煤半圆弯曲试样在层理平行、层理垂直及层理斜交方向上的断裂行为及加载率效应开展研究，据此构建研究区褐煤储层水力压裂造缝模式。结果表明：二连盆地褐煤试样冲击下断裂过程包括弹性变形、断裂及卸载阶段；随加载率提升，试样断裂强度、断裂韧度随之线性增大，研究区褐煤断裂性能加载率效应非常显著。随加载率增大试样破碎程度加剧，层理平行型试样冲击下以层理剪切破碎形式为主，垂直层理及斜交层理试样以冲击压碎式破坏为主并形成大量煤粉，对煤层气排采较为不利。冲击下褐煤岩断裂方位基本与加载方位一致。同时随加载率增大，研究区褐煤断裂过程耗能线性增加。以上表明二连盆地褐煤断裂行为受外部加载率深刻控制。最后提出一种基于加载率效应的煤储层压裂造缝模式调控程序。其中深部应力主控型褐煤储层压裂，压裂中主要采取由近到远逐级增大加载率，而浅层由天然裂缝主控的褐煤储层压裂，压裂中由近到远逐级减小加载率的泵注程序，使压裂裂缝初期由应力主控，后期转为天然裂缝主控。形成近井地带主干裂缝，...     

褐煤活性焦吸附难降解有机废水研究进展

褐煤活性焦是一种以褐煤为主要原料制备的具有吸附和催化功能的新型环保材料，其特点是中孔发达，表面含有多元含氧官能团，优先吸附大分子难降解有机污染物，已广泛用于废气和废水的处理。褐煤活性焦处理难降解有机废水主要有煤化工废水、炸药废水、石油废水、印染废水等，其机理是氢键作用、化学吸附。褐煤活性焦吸附量较小，可通过改性、二次利用等提高吸附量。饱和活性焦可再生或资源化利用以提高利用率、减少二次污染。     

普通立窑褐煤煅烧水泥熟料的工业性试验

本试验提供了普通立窖采用褐煤煅烧水泥熟料的初步结果,提示了褐煤作燃料时的生产控制指标以及相应的工艺技术措施。指出:只要针对褐煤的特性,严格遵守工艺要求,普通立窖是可能采用褐煤来煅烧水泥熟料的。     

维多利亚褐煤的固结和渗透特性试验研究

维多利亚褐煤一般被认为是一种中级岩土材料(IGMs),其岩土工程性质介于常规土体和岩石之间。褐煤富含有机质,其自然结构和物理组分比较复杂。褐煤具有不同于常规软黏土的基本岩土参数,包括自然密度和相对密度低、天然含水率高、孔隙比大,渗透系数相对较低等。采用原状褐煤试样开展了标准室内固结试验,褐煤材料的固结变形曲线主要表现为:初始阶段变形明显且很快完成,初始阶段变形占比很大,在数分钟内应变可达50%,在较明显的拐点之后,后续变形相对较缓慢。标准Terzaghi固结并不能很好地适用于褐煤材料。设计开展了褐煤材料的常水头渗透试验,基于不同超静孔压消散路径采用2种方法测量了褐煤的渗透系数,试验测得的褐煤材料渗透系数值相对较小。     

探析褐煤低温干馏工艺及设备

煤炭是我国的基础能源和重要原料,在国民经济和社会发展中具有重要的战略地位。褐煤资源约占世界煤炭资源的40%以上,中国褐煤约占全国总煤量的13%,但褐煤由于煤化程度低,易风化、易自燃等特点难以大规模利用。本文主要阐述了褐煤低温干馏加工的生产工艺以及褐煤低温干馏工程设备的应用。     

东胜煤田补连塔矿煤物理力学特性试验研究

详细研究了东胜煤田补连塔矿煤的岩石组成、内生裂隙及外生节理的发育特征。测试了煤的抗压强度、抗拉强度及载荷位移全过程曲线。东胜煤田褐煤的力学强度较中国其它地区褐煤高，煤的物理力学特性呈十分明显的各向异性，煤的物理力学特性与应力条件有关。     

文献摘录

密西西比褐煤在固定床气化器中的水蒸汽气化(美)/Boswell,D.R.ete·Fuel Process.Technol.18,37—50(1988)Mar· 为确定密西西比褐煤对德克萨褐煤的气化速率常数,使用了小型固定床反应器,并且比较了由两种煤半焦重量损失和气体体积数据计算出的气化速率常数。使用了一级或2/3级动力方程分析气体产率。以无灰干基计算的密西西比褐煤和德克萨斯褐煤的气化速率常数相当一致。     

褐煤低位发热量的计算

褐煤是最年轻的矿产煤。一般v~r>4O％,焦渣特性为1号者,多属褐煤。褐煤在计算其低位发热量时,非可燃物对热值的影响也与烟煤相似。由大量褐煤煤样的统计计算后发现,褐煤中每1％含量的非可燃物影响热值的范围,约为67.5～74.5卡之间。此外,挥发份高的褐煤,其氢含量一般也较高,故障低的热值也     

Lignite aided dewatering of digested sewage sludge

Mechanical dewatering is commonly used to increase the solids content of municipal sludge prior to its disposal. However, if the rate of filtration is slow, mechanical dewatering can be expensive. In this study, the use of lignite to improve the sludge dewatering is investigated. The effectiveness of lignite conditioning of polyelectrolyte-flocculated sludge is examined using mechanical compression tests. Results show that lignite conditioning in conjunction with polyelectrolyte flocculation gives much better dewatering than the polyelectrolyte flocculation alone. Using Darcy's filtration theory, the specific cake resistance and permeability of the compressed cakes are obtained. Both of these parameters are significantly improved after lignite conditioning. Mercury porosimetry tests on compressed cakes show that the porosity of the lignite-conditioned sludge cake is much higher than that of the polyelectrolyte-flocculated sludge and it increases with increasing doses of lignite. The mercury porosimetry results show that the lignite pore volume of pores greater than 0.5 μm are reduced with increasing sludge ratio indicating that sludge is trapped within these pores, whereas smaller pores are unaffected. The yield stress curves for sludge, lignite and sludge-lignite mixtures show that the sludge filter cake is very compressible, but the lignite-conditioned cake has a range of compressibility which although more than lignite indicate that the cake is relatively incompressible at low pressures. Thus, lignite conditioning acts to maintain the permeability of the filter cake during compression dewatering by resisting cake compression. This leads to a trade-off between the rate of dewatering and the solids content of the compressed cake. With lignite conditioning, the dewatering rate can be increased by a factor of five for the same degree of water removal.     

三轴等压条件下400 ℃内褐煤变形及结构衍化实验研究

 为深入研究褐煤原位注热开采过程物性特征的衍变,应用高温高压实验平台,研究7 MPa三轴等压条件下,Φ50 mm×100 mm褐煤以3 ℃/min升温速率由室温升高到400 ℃过程中及恒温恒载5 h的变形特征规律。并应用显微CT、压汞、液氮吸附解吸方法综合分析褐煤不同孔径范围的孔裂隙衍化规律。研究发现：热力耦合作用下,褐煤变形过程可以划分为缓慢膨胀阶段(室温～170 ℃)、剧烈压缩阶段(170 ℃～289 ℃)及缓慢压缩阶段        (289 ℃～400 ℃),褐煤脆性–韧性转变临界温度为180 ℃。恒温恒载5 h过程中,褐煤轴向线应变终值随温度的升高先增大后减小,最大值为2.5%(200 ℃),最小值为1.3%(100 ℃)。褐煤最大径向累积压缩应变约为19%        (400 ℃),最大体积累积压缩应变约为41%(400 ℃)。热力耦合作用下,褐煤变形对其结构衍化有重要影响。随着温度的升高,褐煤总孔隙率表现为先增大后减小,孔裂隙率极大值为21.46%(200 ℃),最小孔裂隙率为7.61%        (23 ℃);主要孔裂隙的孔径逐渐增大。褐煤孔裂隙率衍化具有较好的分形特征,随着温度的升高,孔裂隙率的分形维数表现为先减小后增大、分形初值则先增大后减小。     

褐煤固定床加压气化副产品的特性及利用

介绍了黄县和沈北两种褐煤在Ф650mm固定床加压气化炉中进行气化试验的结果，探讨了轻质油、焦油和含酚污水等气化副产品的特性及其利用的途径。     

微米级褐煤粉尘爆炸压力试验研究

摘 要：使用近球形煤尘爆炸装置,以微米级褐煤粉尘为研究对象,测试爆炸压力特性变化规律。研究表明：微米级褐煤粉尘爆炸最大压力为0.73 MPa,最大压力上升速率为65.78 MPa/s,该爆炸强度可对爆源附近人员造成极大危害。爆炸前后参与爆炸的挥发分质量分数达到26.25%,表明挥发分是参与褐煤粉尘爆炸的主体成分。随喷尘压力在1.4~2.6 MPa范围内增大,爆炸最大压力和最大压力上升速率均先增大后减小。喷尘压力为1.8~2.2 MPa时,爆炸最大压力相对较大,表明该条件下褐煤粉尘在点火头附近扩散得最充分。随点火延迟时间在70 ~130 ms范围内增大,爆炸最大压力和最大压力上升速率均先增大后减小,最佳点火延迟时间约为100 ms,说明该条件下褐煤粉尘颗粒达到最佳分散状态,爆炸强度最大。     

关于褐煤在3АД—13型煤气发生炉中的气化研究

本文对低发热量褐煤在3AД-13型煤气发生炉中的气化问题进行了研究,根据煤质及特点,设计了气化试验的工艺流程,并且进行三个阶段性的试验,取得的可靠数据分别列成表格,同时对褐煤在3AД-13型煤气发生炉中的气化特性作了某些理论性探讨和分析。为使褐煤能在该型发生炉中进行有效的气化以及提高其气化强度,还提出了几点改进措施。     

温度对褐煤渗透特性影响的试验研究

采用太原理工大学采矿工艺研究所研制的煤(岩)MDS200三轴渗透试验机,在不同应力、不同温度条件下,对内蒙乌盟矿区褐煤进行热渗透试验研究。研究结果表明:随着煤层埋藏深度的增加,即体积应力的增加,褐煤渗透率总体上是呈下降趋势;在温度和体积应力不变的情况下,褐煤随着孔隙压力的增大,渗透率呈先下降,再增大的趋势,其临界点为2MPa左右;在体积应力和孔隙压力不变的情况下,随着温度的升高(100℃以内),褐煤的渗透率呈先下降,再急剧增大,再减小的趋势,渗透率的极低点温度为50℃左右,极高点温度80℃左右;当温度小于50℃时,随着孔隙压力的增大,渗透率呈下降趋势,当温度高于50℃时,随着孔隙压力的增大,渗透率呈上升趋势。     

Radioenvironmental survey of the Megalopolis lignite field basin

The Megalopolis lignite field basin in southern Greece, with Megalopolis-A and B lignite-fired power plants in operation (total 900 MW), has been repeatedly investigated during the past 25 years by the Nuclear Engineering Section of the National Technical University of Athens (NES-NTUA). The present work aims at an integrated radioenvironmental approach leading to the dose assessment to the public and to the plants staff. This approach includes systematic sampling of lignite and barren at the local lignite mines feeding the power plants and sampling of lignite, fly-ash and bottom ash at the power plants for the determination of the activity of the natural radionuclides 226Ra, 232Th, 40K, 234Th and 210Pb. Furthermore, the following measurements and samplings were conducted in 25 selected sites within 10 km around the power plants: soil sampling for the determination of the above radionuclides, radon concentration and exhalation rate measurements, soil gas radon concentration measurements, dose measurements and calculations, determination of air-particulate matter concentration, etc. The results obtained allowed for the mapping of the parameters studied which lead to useful conclusions. Dosimetric calculations for the population living around the power plants and the plants staff were also performed based on the guidance of UNSCEAR (1982 report).     

pH-Wertpufferung im Abstrom von Reaktionswänden

Sequenced column experiments were conducted in order to assess the impact of elevated pH caused by two possible reactive media combinations for permeable reactive barriers (Fe°/Oxygen Release Compound (ORC) and Fe°/activated carbon) on the groundwater quality in a lignite sand. In the experiments, pH values > 9,5 downgradient of Fe° and ORC reactors were buffered to lower values by the lignite sand. In the lignite sand, pH fronts formed, propagating downgradient at a velocity that was 220–1,100 times slower than the groundwater flow velocity (0.71 and 0.83 m/d, respectively). The amount of base equivalents buffered in both experiments (52 and 7.3 meq/kg sediment, respectively) depended mainly on the different amounts of base equivalents present in the inflowing solutions. The majority of the base neutralization can be explained by the deprotonation of functional groups on mineral surfaces and organic carbon. The extent of other buffering mechanisms, such as mineral dissolution and pyrite oxidation, was limited in time. For the lignite sand examined here, high pH values downgradient of permeable reactive barriers will be limited to a narrow zone, even in the long term, and high pH values will not limit the possible implementation of a permeable reactive barrier.     

Multi-component adsorption of Ag(I), Cd(II) and Cu(II) by natural carbonaceous materials

Adsorption of silver, cadmium and copper from aqueous solutions by natural carbonaceous materials was investigated. The studied series of natural materials (spruce wood, pine bark, cork, peat, fusinite, lignite, oxidised lignite, bituminous coal and anthracite) was extended to include industrial carbon-rich materials: coke, activated carbon F-400 and Multisorb 100. Adsorption was tested on a single-component system and on the binary and ternary mixtures. All the materials used differ in their ability to adsorb selected metals. The adsorption of metals is significantly affected by the presence of other ions in solution. Total metal uptake was considerably higher in a mixture than single-ion adsorption. Chemical reactions, such as precipitation and reduction of metallic silver, play a role in metal uptake by bituminous coal, coke and activated carbon.     

南宁盆地煤层力学特性研究及工程应用

南宁盆地的地层中夹有数层煤层,以含中~高灰份、低~中硫的含油褐煤为主,约占95%,交错出现在第三系泥岩中,分布于南宁盆地局部区域。它的存在常常给工程建设带来很大问题,但由于其厚度较薄,相关的物理力学特性研究不足,在工程实践中尚未引起足够重视。通过现场及室内试验对煤层的承载能力和强度进行研究,利用改进的点荷载试验仪分析煤层的应力应变关系,并采用有限元法对某工程桩基进行模拟计算,研究分析了煤层的存在对桩基础沉降变形、应力分布的影响,为从事设计与进一步研究提供参考。