Towards the improvement of thermal efficiency in lignite‐fired power generation: Concerning the utilization of Polish lignite deposits in state‐of‐the‐art IGCC technology

Integrated coal Gasification Combined Cycle (IGCC) is the most advanced technology for coal‐fired power generation. The two‐stage entrained flow gasification process allows for the use of a wide range of coal, as long as the gasification temperature is above the ash melting point of a used fuel. In this gasification technology, lignite, which often has a low ash melting point, can be preferably utilized. However, ash fluidity is also another importance, because the behaviour of molten slag can diminish a stable ash discharge from a gasifier. As the eligibility of coal ash properties is a considerable factor, water physically and chemically kept in lignite (30 – 60% in mass) attributes to deteriorating gasification efficiency, because it causes significant heat loss and increasing oxygen consumption. Developing a thermal evaporative lignite drying method will be a necessary attempt to apply lignite to the coal gasification process. For those preceded objectives, coal and ash properties and drying characteristics of several grades of Polish lignite, extracted from Belchatow and Turow deposits, have been experimentally investigated in a preliminary study evaluating the applicability and consideration for its utilization in state‐of‐the‐art clean coal technology, IGCC. This paper particularly discusses the eligibility of Polish lignite from the perspective of the fusibility and fluidity of ash melts and the fundamental drying kinetics of lignite in superheated steam in the light of water removal. The viscosity of ash melts is measured at high temperature up to 1700 °C. In the drying tests, the significant influence of structural issues, because of the provenance and origin of lignite on the drying characteristics, was found by applying the method of sensitivity analysis of physical propensity. This paper concludes that the investigated Polish lignite has characteristics favourable for utilization in IGCC technology, once the precautions related to its high moisture have been carefully addressed. Copyright © 2016 John Wiley & Sons, Ltd.     

湖北郧西西部地区金、锑矿成矿要素及成矿模式

湖北郧西西部地区金、锑矿位于秦岭泥盆系多金属成矿带的东南部镇旬成矿区的东侧,通过对郧西西部地区金、锑矿的成矿规律的综合分析和成矿要素的总结归纳,认为该区金、锑矿受构造、岩性控制。     

内乡县李沟矽线石矿床地质特征及矿床成因

李沟矽线石矿床位于“豫西南高铝三石成矿带”中,受区域地层、构造及岩浆活动影响显著,属沉积变质矿床。该矿床赋存于古元古界雁岭沟组片岩内,矿床受地层和褶皱构造控制,矿体呈层状产出,成矿地质条件较好。本文在研究前人地质勘查资料的基础上,总结了该矿床的区域及矿区成矿地质条件,并对该地区矽线石矿的矿床成因、找矿标志进行了探讨。笔者认为李沟矽线石矿床及区域地层、构造、岩浆活动构成了“三位一体”的控矿机制,该矿床的周边地区内矽线石矿床(点)分布较多,李沟矽线石矿床及外围地区具有寻找矽线石矿的较好找矿前景。     

THE NATURE AND ORIGIN OF AUTHIGENIC CHLORITE AND RELATED CEMENTS IN OLIGO–MIOCENE RESERVOIR SANDSTONES,TAPTI GAS FIELDS,SURAT DEPRESSION,OFFSHORE WESTERN INDIA

Reservoir sandstones in the Mid‐ and South Tapti gas fields in the Surat Depression (Mumbai Offshore Basin, western India) have been investigated using a range of petrographic techniques, isotope geochemistry and basin modelling. Authigenic chlorite is abundant in the shallow‐marine sandstones of the Miocene Mahim Formation, a major reservoir rock in the Mid‐ and South Tapti fields, which are described here in terms of their quality and diagenetic characteristics. The sandstones are currently at burial depths of between ～1500 and 2800m. The authigenic chlorite has had a significant impact on the resulting reservoir quality of the sandstones and is interpreted to have originated as odinite clay of the verdine facies that replaced faecal or pseudo‐faecal pellets, together with volumetrically small but abundant grain coatings and grain rims, and formed at the site of major riverine iron influx onto the shallow‐marine shelf during periods of relatively low sea level. Pellets have been variably compacted to form pseudomatrix. Reservoir sandstones from similar depositional settings on the west coast of India or other sub‐tropical settings are likely to exhibit comparable diagenetic effects on reservoir quality. Compositionally, the chlorite is the iron‐rich form known as chamosite. The chemistry of all the chlorite morphologies is the same in all studied samples. Oxygen isotope analyses of carbonate cements in the Mahim Formation sandstones have provided an approximate temperature framework for diagenesis of the non‐carbonate cements. Oxygen isotope results for the chlorite, however, suggest much higher temperatures than its position in the paragenetic sequence would warrant. These results suggest that the clay formed first as 1:1 layer clays, in this case odinite, which were then transformed to Fe‐chlorite as burial depths and temperatures increased. Reservoirs in the Mahim, Daman and Mahuva Formation sandstones are thus greatly influenced by the diagenesis of authigenic chlorite and locally by the precipitation of carbonate cements. Reservoir quality is good where thick, continuous chlorite rim cements are present and where chlorite pellets are sufficiently indurated for them not to be compacted. Chlorite rim cements have reduced the extent of quartz overgrowth cementation in the sandstones.     

玄武岩催化甲烷裂解制 C2 烃

以天然玄武岩为甲烷裂解催化剂,通过XRF、XRD、SEM及XPS对催化剂组成、结构、表面活性物种进行了研究。利用固定床反应装置考察了不同反应温度、空速条件下玄武岩催化甲烷裂解制C_2烃的效果。结果表明,在气体空速为4 L·h-1条件下,当反应温度为1 225 K时,甲烷的转化率为7.66%,C_2烃的选择性为33.64%;当反应温度升至1 325 K时,甲烷的转化率可达17.13%,同时C_2烃的选择性为27.21%。相同温度下,气体空速越大,乙烷的选择性越高,乙炔的选择性越低。催化剂活性因表面积炭的产生而降低,积炭类型为芳烃积炭。     

东昆仑沙丘低缓磁异常区深部铁多金属矿床找矿标志

那陵郭勒河沙丘地区位于东昆仑祁漫塔格早古生代裂陷槽,经历了早古生代及晚古生代—早中生代的复合造山作用,发育多期次岩浆活动和成矿作用,具有较好的铁多金属找矿前景。文章通过研究沙丘铁多金属矿的成矿地质背景、矿床特征、地磁异常和地球化学异常等,探讨了其找矿标志。研究表明:沙丘地区铁多金属矿床成因类型属接触交代型(矽卡岩型),矽卡岩与磁铁矿体在空间分布紧密共生,是重要的找矿标志;引起该区磁异常的主要地质体为闪锌磁铁矿矿石、闪锌磁铁矿化矽卡岩、矽卡岩、闪长岩、硅质岩、玄武岩、钾长花岗斑岩;利用物探磁异常找寻磁铁矿作用显著,在低缓磁异常区、正负异常接触部位是找寻铁多金属矿最重要也是最直接的找矿标志。     

秘鲁Pachagon铜矿床岩石地球化学特征及成因

帕加贡铜矿床位于秘鲁北部重要斑岩成矿带上,文章就该区岩相学、矿相学、岩石化学及稀土微量元素地球化学等方面进行了研究,并依据宏观地质产状、矿石矿物组成、结构构造及生成顺序、主微量元素组成特征等,总结了矿床成因,推测矿区成矿模型。该区砂岩中的构造破碎带是矿体的主要产出部位,为受构造控制的次生铜富集带,但有证据显示其成矿与深部岩体存在一定关系:(1)矿石镜下见热液成因黄铜矿及半自形中高温矿物晶出;(2)铜的富集过程伴随不相容元素含量的递增;(3)矿物组合由浅至深辉铜矿减少,黄铜矿、磁黄铁矿增加,且随深度增加,硅化逐渐增强。综合判断矿区成矿类型:浅部为受构造控制的次生富集带铜矿,深部为与岩体有关的斑岩型铜矿床。     

金属矿床评价计算模型的综合比较与选优

评估体系是实现企业开发决策及其科学生产的主要手段。本文通过对综合评价法、TOPSIS法和ELECTRE法的分析与比较,将三种算法相济运用;在三种算法所得结果不一致时,得出用社会选择方法来判定那个方法的评价结果可信度更高的结论。     

鹤壁矿区煤系共伴生矿物开发利用研究

通过对鹤壁煤业集团公司一矿煤系共伴生矿物的分析研究,提出了鹤壁矿区煤系共伴生矿物开发利用的途径。