New Data on Coal, Gypsum, Iron and Silica Sand Deposits and Geochemical Exploration (Pakistan): Revision of 25 Years History of Dinosaur Discoveries from Pakistan

Discoveries of many coal seams at depths by drilling carried by Geological Survey of Pakistan in Sor Range and Harnai Gochina, extended the coal seams at depth which is challenge for mine owners to exploit feasibly. Bed to bed gypsum samplings (and their chemical analyses) of huge gypsum deposits from Sulaiman foldbelt is a base for industrialist and also planers to develop cement and gypsum industries to increase export and foreign exchange for the development of area and Pakistan. Low and high grade sedimentary iron deposits, silica sand and uranium host rocks and their extensions in Sulaiman and Kirthar foldbelts are presented. Anomalies of a few base metals arise as a result of geochemical exploration carried at part of Loralai District of Balochistan. Theropod dinosaurs were frequent in India, while Poripuchian titanosaurs (Sauropoda, Dinosauria) were frequent in Pakistan. Besides some ichnotaxa, many bone taxa such as 1 titanosauriform, 14 titanosaurian sauropod (including one new titanosaur), and 3 theropod dinosaurs are established from Pakistan. Among these 12 titanosaur species and 3 theropod species are named in about 10 km2 area of Vitakri dome and 2 titanosaur species are named in about a few hundred square meter area of Mari Bohri (Kachi Bohri) which is about 10 km westward from Vitakri dome. Pakistan is a unique country which discoverd 14 diversified titanosaurs in a short area and also in a short period (67 - 66 million years ago/Ma). About 400 bones found from a few meter thick upper part of upper shale horizon of latest Maastrichtian Vitakri Formation which is base for titanosaur taxa. Cranial material is in low fraction (but include significant diverse snouts), caudal vertebrae are prominent, the cervicals, dorsals and sacrals have significant numbers, forelimb and hind limb bones have balanced fraction. Humeri, femora and tibiae are most common. To know the position of Pakistani titanosaurs among titanosaurs and sauropods, there is a need to extend list of characters for phylogenetic analyses. This broad feature list should include main characters of titanosaurs from Pakistan and also from global world.

Utilization of Cement Kiln Dust (CKD) with Silica Fume (SF) as a Partial Replacement of Cement in Concrete Production

This research aimed to clarify the role of by-product materials, such as CKD with SF as partial replacement by weight of cement in concrete manufacturing and inclusion on different characteristics of concrete. Concrete test specimens were mixed with 0%, 5%, 10%, 15%, 20% and 25% (CKD) with 15% (SF) as partial replacement by weight of Cement (CEM I-52.5N). Fresh concrete properties have been evaluated by workability measurement slump test. While hardened concrete properties have been evaluated by compressive, split tensile and flexural strengths tests at ages 7, 28 and 56 days, but evaluated for bond strength, modulus of elasticity and chemical composition measurement with X-Ray Fluorescence at age of 28 days. The test results have revealed that the increase of CKD amount with fixed amount of SF in concrete mixtures as partial replacement by weight of cement leads to gradual decrease of fresh concrete workability. In concrete mixtures, 20% CKD in the presence of 15% SF as partial replacement by the weight of cement are the optimum ratios which can be used without any negative effect on mechanical properties compressive, indirect tensile, flexural and bond strength at all the ages of concrete. Also modulus of elasticity and bond strength increased by 8.81% and 0.69% respectively at the age 28 days compared with control mixture.

用后焦炉硅砖的显微结构

借助于OM、SEM、EDAX和XRD分析手段对用后焦炉炭化室硅砖炭化面和燃烧面的显微结构变化做了研究。炭化面亚稳方石英和残存石英几乎全部鳞石英化,吸收焦炭中的MgO、Al2O3、P2O5和CaO,生成磷酸三钙(C3P)、假硅灰石和玻璃相。由于煤气裂解作用在砖的气孔中形成碳沉积,气孔封闭化。燃烧面由鳞石英、硅酸盐、磷酸三钙、玻璃相和无定形碳组成,但沉积碳较少。

Microstructure Analysis of Used Silica Brick in Coke Oven of Meisteel

Microstructure analysis shows quartz remains more or less in used silica brick for coking chamber of coke oven, and quartz gradually becomes metastable cristobalite and then translates into tridymite in used brick for high temperature combustion chamber. Phase change of silica brick only limits to transformation of quartz and metastahie cristobalite. When finished, structure of silica brick tends to stable. Carbon sedimentates and graphitize. helping to protect the silica brick and improve heat conductivity of silica brick for coking chamber.

RUL of Un-burnt High Purity Silica Bricks Used in Glass Industry

High purity silica bricks have stable physical properties,except for the RUL （0.2 MPa） exhibiting extreme two different levels of high-level RUL T0.6 of 1 683-1 686 ℃ and low-level RUL T0.6 of1 174-1 184 ℃.The low RUL phenomenon was researched,the formation reasons and solutions were analyzed in this paper.The low-level RUL T0.6 of 1 174-1 184 ℃ of the un-burnt high purity silica bricks is a pseudo RUL T0.6 phenomenon for the transformation of crystalline morphology.The real RUL T0.6 of the specimen hot treated at 1 093 ℃ is ＞ 1 680 ℃.Therefore,the un-burnt high purity silica bricks shall be hot treated at about 1 100 ℃ firstly before testing RUL.For the heating up of the lining of glass tank arch,baking curves with long holding time at 1 100 ℃ shall be strictly obeyed to avoid the obvious shrinkage negatively influencing the lining stability.

Development and Application of Zero Expansion Silica Brick for Hot Repairing of Coke Oven

In order to meet the needs of hot repairing technology of coke oven, the zero expansion, silica brick with super properties has been developed, and the problem of poor thermal stability of common silica brick has been over-comed . This product can be directly used after being rapidly heated after construction. At present, it has been applied in coke ovens in Italy and Baosteel.

改性中孔分子筛SBA-16薄膜的合成及表征

在酸性条件下,以导电玻璃(ITO)为基底合成了SBA-16分子筛膜.所制备的SBA-16膜孔径均匀,具有体心立方结构(属于Im3m空间群),SBA-16膜的晶胞参数为18.6nm.TEM,SEM和XRD等技术研究表明,加入少量的AlCl3盐于形成膜的母液并且采用RSiX3对导电玻璃基底进行处理,能够明显改善SBA-16膜的连续性而不影响孔结构.红外(FTIR)研究结果表明,SBA-16膜的表面硅羟基和结晶水很少,膜很稳定.XPS研究表明,加入少量MnCl2对SBA-16膜进行改性,可以提高膜的导电性.

新型球形纳米空心SiO_2的模板合成方法研究

以纳米碳酸钙颗粒为新颖的无机模板剂,硅酸钠为无机硅源,通过溶胶-凝胶法形成CaCO3/SiO2的核壳结构;随后通过高温煅烧、酸溶和干燥处理,合成出了具有高比表面积的球形纳米空心二氧化硅粒子.然后,分别采用TEM,SEM,EDS,XRD,FTIR和TG等测试手段对样品进行了分析和表征,并考察了不同合成条件,如反应温度、反应pH值、煅烧温度和包覆反应时SiO2/CaCO3的配比对纳米空心二氧化硅粒子的比表面积变化.实验结果表明:较高的反应温度如60～80℃,pH值9左右、SiO2包覆量为碳酸钙质量的10%,以及煅烧温度为700℃,有利于形成空心形貌较好、比表面较大的球形纳米空心二氧化硅.

Performance of High Thermal Conductivity Dense Silica Bricks and Their High Thermal Conductivity Mechanism

High thermal conductivity dense silica bricks have the higher thermal conductivity than ordinary silica bricks,which is conducive to the realization of energy saving and emission reduction in the iron and steel industry.The performance of ordinary silica bricks and high thermal conductivity dense silica bricks was compared,and the high thermal conductivity mechanism was analyzed.The results show that(1)compared with ordinary silica bricks,high thermal conductivity dense silica bricks have the characteristics of higher thermal conductivity,lower apparent porosity,higher tridymite content,higher compressive strength,and higher thermal expansion;(2)by increasing the tridymite content and reducing the porosity,the close packing of honeycombα-tridymite improves the density and continuity of the SiO_(2)frame structure of the silica bricks,and the larger area perpendicular to the heat transfer direction improves the thermal conductivity of the bricks;(3)the densification of the silica bricks also increases the thermal expansion of the bricks,but they still meet the standard requirements.

Properties of Rapid Hardening Controlled Low Strength Material Made of Recycled Fine Aggregate from Urban Red Brick Construction Waste

In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardening controlled low strength material, which utilizes both rapid hardening sulphoaluminate cement and recycled fine aggregate from urban red brick construction waste. Totally, sixteen mixtures were prepared for the experiment with different cement-to-sand ratios and water-to-solid ratios. The flowability and bleeding rate of fresh mixture were measured to evaluate its workability, and the compressive strength of hardened mixture was tested to evaluate its rapid hardening and mechanical properties. Test results indicate that rapid hardening controlled low strength material containing recycled fine aggregate from urban red brick construction waste can achieve the desirable flowability, but the bleeding rate increases with the increase of flowability. In addition, 2-hour compressive strength can reach 0.08 - 0.12 MPa, and 4-hour compressive strength is 0.32 - 1.54 MPa, which can meet the requirements of emergency backfill construction. At last, based on the derived compressive strength, a fitting model for predicting compressive strength evolution of this new rapid hardening backfill material is developed, which fits accurately with these experimental data.

聚吡咯/SiO_2作导电助剂的水性环氧抗静电涂料的制备

以导电性聚吡咯/二氧化硅(PPy/SiO2)复合材料作导电助剂,与环氧树脂乳液混合,经聚酰胺X-650固化后,制备了电导率在10-9～10-4S·cm-1之间的水性环氧抗静电涂料。结果表明:PPy/SiO2用量为环氧乳液的2%(质量分数,下同)时,环氧涂层的电导率可从10-16S·cm-1提高到1.2×10-9S·cm-1,而且PPy/SiO2用量低于8%时,涂层具有良好的综合性能,对玻璃和马口铁附着力为1级,耐冲击性大于50cm,铅笔硬度H,耐水性和柔韧性优良。SEM观察结果表明:PPy/SiO2在环氧涂层中具有良好的分散性,且与环氧基体结合比较紧密。

Investigation on Production and Markets of Silica Bricks in China

The annual output of China ' s silica brick amounts up to over 300 thousand tons, which accounts for more than 10% of the total output of silica bricks in the world. Besides satisfying domestic markets , China s silica bricks have been exported to many countries and regions such as Japan, USA etc. In this paper, the situation of silica bricks production, technology, sales and exporting have been described. Also suggestions on improvement of silica bricks quality and exporting, corporation with foreign partners have been put forward in order to win larger market share both at home and abroad.

硅铝凝胶粉结合SiAlON增强A1_2O_3-SiC-C浇注料

以电熔致密刚玉和碳化硅为骨料,硅铝凝胶粉、氮化硅粉、硅粉为细粉,制成SiAlON增强Al2O3-SiC-C浇注料,研究了硅铝凝胶粉的加入量分别为1%、3%、5%(质量分数,下同)时对此浇注料的烧结性能、力学性能的影响。结果表明:采用硅铝凝胶粉取代纯铝酸钙水泥作结合剂,可使SiAlON增强Al2O3-SiC-C浇注料在经中温、高温热处理后的常温抗折强度及耐压强度较大提高,中温、高温强度提高幅度更大。另外,随着硅铝凝胶粉加入量的增加,浇注料的常温及高温强度呈先增大而后减小的趋势。由X射线衍射和扫描电镜分析结果可知,硅铝凝胶粉的加入既有利于降低βSiAlON的生成温度,又可以减少材料中的低熔物质。分布均匀、发育良好的粒状βSiAlON的形成是SiAlON增强Al2O3-SiC-C浇注料较水泥结合浇注料强度高的根本原因。

染矽尘大鼠早期肺组织Ⅰ、Ⅲ型胶原的表达

目的探讨染矽尘大鼠早期肺组织中Ⅰ型、Ⅲ型胶原形成的时间规律。方法采用气管暴露法建立矽肺动物模型。取肺组织制作石蜡切片,天狼猩红法染色,偏振光显微镜观察Ⅰ、Ⅲ型胶原的表达,用图像分析系统对Ⅰ、Ⅲ型胶原进行定量分析。结果染矽尘后第3天,Ⅲ型胶原开始增生,染矽尘后第7天,Ⅰ型胶原开始增生,直至染矽尘后第28天。这2种胶原进行性增加。Ⅰ、Ⅲ型胶原阳性面积百分比在染矽尘后均有不同程度的增加。染矽尘后第7天、第14天、第21天、第28天,Ⅰ型胶原阳性面积百分比分别增加27.12(P<0.01),24.73(P<0.01),16.01(P<0.05),52.45(P<0.01)。染矽尘后第3天、第28天,Ⅲ型胶原阳性面积百分比分别增加2.20(P<0.01)、24.13(P<0.01)。结论染矽尘大鼠Ⅰ、Ⅲ型胶原明显增加。Ⅰ、Ⅲ型胶原增生出现的时相有所不同,染矽尘后第3天,Ⅲ型胶原开始出现,染矽尘后第7天,Ⅰ型胶原开始形成,此后,Ⅰ、Ⅲ型胶原呈进行性增多的趋势。天狼猩红-偏振光显微镜法是一种定量检测Ⅰ、Ⅲ型胶原的更加准确的方法。

Effects of NaOH Concentrations on Properties of the Thermal Power Plant Ashes-Bricks by Alkaline Activation

The use of the thermal power plant ashes including fly ash(FA) and bottom ash(BA) for producing unfired building bricks(UBB) using sodium hydroxide(NaOH) solution as an alkaline activator was investigated. A low applied forming pressure of 0.5 MPa and various NaOH concentrations of 5, 8, 10, and 12 M were used for the preparation of brick samples with different solution-to-binder(S/B) ratios of 0.35 and 0.40. The bricks were subjected to various test programs with reflecting the effect of both NaOH concentrations and S/B ratios on the brick’s properties. The compressive strength, unit weight, ultrasonic pulse velocity, and thermal conductivity of bricks increased with increasing NaOH concentration, whereas the contrary trend was found with increasing S/B ratio. Also, the water absorption of bricks was observed to reduce with increasing NaOH concentration and decreasing S/B ratio. As the results, the combined utilization of both low forming pressure and coal power plant ashes can produce the UBBs with low unit weight, low heat conductivity, and acceptable strength and water absorption rate as stipulated by TCVN 6477-2016. Furthermore, the outcomes of chemical analysis and microstructure observation also demonstrate that a high concentration of the Na OH promoted the geopolymerization process. Notably, the use of NaOH solution of either 10 M or above is recommended for the production of UBBs, which are classified as grade M5.0 or higher.

SiO_2气凝胶表面特性对其吸附性能的影响

以多聚硅 E-40为硅源,采用溶胶-凝胶方法,通过常压干燥、表面修饰、450℃热处理等工艺制备了具有不同表面特性的 SiO_2气凝胶。用扫描电镜 SEM,^(13)C,^(29)Si NMR 谱以及孔径分布仪对其结构进行了表征,并对其吸附特性进行了研究。结果表明:在不同制备条件下,SiO_2气凝胶的表面亲、疏水特性差异非常大,比表面积、孔体积、孔径以及对有机物吸附量的变化也很大。SiO_2气凝胶具有纳米多孔结构,较好的疏水、亲水特性可调性,很强的吸附能力,具有广阔的应用前景。

Effect of Nano Silica on Hydration and Microstructure Characteristics of Cement High Volume Fly Ash System Under Steam Curing

The influences of nano silica (NS) on the hydration and microstructure development of steam cured cement high volume fly ash (40 wt%, CHVFA) system were investigated. The compressive strength of mortars was tested with different NS dosage from 0 to 4%. Results show that the compressive strength is dramatically improved with the increase of NS content up to 3%, and decreases with further increase of NS content (e g, at 4%). Then X?ray diffraction (XRD), differential scanning calorimetry-thermogravimetry (DSCTG), scanning electron microscope (SEM), energy disperse spectroscopy (EDS), mercury intrusion porosimeter (MIP) and nuclear magnetic resonance (NMR) were used to analyze the mechanism. The results reveal that the addition of NS accelerates the hydration of cement and fly ash, decreases the porosity and the content of calcium hydroxide (CH) and increases the polymerization degree of C-S-H thus enhancing the compressive strength of mortars. The interfacial transition zone (ITZ) of CHVFA mortars is also significantly improved by the addition ofNS, embodying in the decrease of Ca/Si ratio and CH enrichment of ITZ.

聚酯/无机杂化分子间键合作用及微结构相关性的光谱研究

采用FTIR ,UV Vis,WAXD和DSC手段,研究了分子间为非共价键化学结合的PCL/SiO2 高分子无机杂化透明材料组分间的键合型式;分子间特殊氢键相互作用行为与结晶性聚合物在杂化材料中的微结构相关性。结果表明,杂化体系中PCL高分子与SiO2 无机组分间的键合,主要是依赖于杂化体系中较强的分子间氢键相互作用,其作用强度随无机相TEOS含量而变化。体系中氢键相互作用增加使PCL结晶高分子的相对结晶度下降,杂化材料的光学透明性提高。同时对体系中高分子 无机组分的微相分离尺度产生影响。

Reactivity of Fine Quartz in Presence of Silica Fume and Slag

Dune sand is a very abundant material in south of Algeria. Its high silica content gives a partial pozzolanic reactivity due to its crystalline state. This paper investigates the evolution of cement hydration based on a binary addition particularly the reactivity of dune sand finely ground in the presence of an amorphous addition: silica fume or blast furnace slag. Thus, four combinations of binary additions by substitution have been chosen. The X-ray diffraction analyses performed on cement pastes containing additions have shown the importance of the mineralogy and silica content of additions on their pozzolanic reactivity. Dune sand becomes reactive at long term, especially when associated up to 10% of amorphous addition (blast furnace slag or silica fume). It results an increasing in mechanical strength of Ultra High Performance Concrete (UHPC) and an improvement of the microstructure.

Al-modified yolk-shell silica particle-supported NiMo catalysts for ultradeep hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene:Efficient accessibility of active sites and suitable acidity

Yolk-shell SiO2 particles(YP)with center-radial meso-channels were fabricated through a simple and effective method.Al-containing YP-supported NiMo catalysts with different Al amounts(NiMo/AYP-x,x=Si/Al molar proportion)were prepared and dibenzothiophene(DBT)and 4,6-dimethyl-dibenzothiophene(4,6-DMDBT)were employed as the probes to evaluate the hydrodesulfurization(HDS)catalytic performance.The as-prepared AYP-x carriers and corresponding catalysts were characterized by some advanced characterizations to obtain deeper correlations between physicochemical properties and the HDS performance.The average pore sizes of series AYP-x supports are above 6.0 nm,which favors the mass transfer of organic sulfides.The cavity between the yolk and the shell is beneficial for the enrichment of S-containing compounds and the accessibility between reactants and active metals.Aluminum embedded into the silica framework could facilitate the formation of Lewis(L)and Brønsted(B)acid sites and adjust the metal-support interaction(MSI).Among all the as-synthesized catalysts,NiMo/AYP-20 catalyst shows the highest HDS activities.The improved HDS activity of NiMo/AYP-20 catalyst is attributed to the perfect combination of excellent structural properties of the yolk-shell mesoporous silica,enhanced acidity,moderate MSI,and good accessibility/dispersion of active components.