高温煤气脱硫剂的研制及活性评价

采用钢厂的废物赤泥为活性成分,添加不同的黏结剂及造孔剂制备出了高温煤气脱硫剂。对制备的脱硫剂的脱硫活性和机械强度进行了测试与表征。结果表明,以赤泥为原料制备的脱硫剂是一种性能优良的脱硫剂。黏结剂的添加不仅能够提高脱硫剂的抗粉化性能,而且也可通过改变脱硫剂的织构来影响脱硫效果,分别添加三种黏结剂后,脱硫剂的机械强度最高的由188 N/cm提高到230 N/cm。同时通过对脱硫剂的硫容和穿透曲线进行的综合考察,发现高机械强度的脱硫剂,并不一定有高的硫容和脱硫效率,而适宜的强度能够提高脱硫剂的脱硫效率。     

氧化铝成型的Pt-SO42-/ZrO2-Al2O3上n-C50/C60的异构化性能

采用浸渍法制备了Pt-SO₄ ^2-/ZrO₂-Al₂O₃（PSZA）催化剂,考察了黏结剂拟薄水铝石的来源对PSZA异构化活性和机械强度的影响,确定了较为适合的黏结剂来源。对氢氧化锆母体制备进行从25g放大10倍至250g,研究放大催化剂的异构化性能。在此基础上考察了Al₂O₃黏结剂含量对PSZA异构化活性和机械强度的影响。采用XRD、TG、XRF等手段对催化剂进行了表征,结果表明：拟薄水铝石的来源不同,结晶度不同,制备的催化剂的异构化活性与机械强度均有差别,拟薄水铝石的结晶度越高,制备的催化剂上的硫含量越低,异构化活性越高,机械强度也越高。此外,放大10倍制备的催化剂异构化性能没有明显变化。黏结剂含量对催化剂的初始异构化活性没有明显影响,而反应稳定性随着黏结剂含量的提高大幅度降低。兼顾催化剂的异构化活性与机械强度,较适宜的Al₂O₃质量分数为5%～10%。     

聚丙烯腈基碳纤维高温碳化过程研究进展

简要介绍了高温碳化炉设备的基本结构和碳化机理,归纳了高温碳化过程中温度梯度、升温速率、纤维停留时间和保护气体流动状态等因素对碳纤维性能的影响。针对目前高温碳化炉设计过程中理论依据匮乏的问题,提出使用仿真软件对高温碳化炉的温度场进行模拟,增强计算机仿真在高温碳化炉设计中的应用与拓展,为后期高温碳化炉的温区设置提供借鉴。     

焦作无烟煤制备型煤的混料配方实验研究

介绍了以水泥、黏土、腐植酸钠、膨润土、沥青为黏结剂,用焦作无烟煤制备型煤的试验研究。通过对型煤冷强度及热强度的测定,探究了不同黏结剂配比对型煤强度性能的影响。结果表明,焦作无烟煤制取型煤的最佳黏结剂配方为黏土和沥青的掺入量分别占总量的10%和5%。此研究对焦作无烟煤粉煤的洁净利用有较大的实际应用意义。     

挤出成型制备高强度氮化硅陶瓷

以羧甲基纤维素(CMC)为黏结剂，通过挤出成型的方式制备氮化硅陶瓷管材，并研究了黏结剂含量对陶瓷管材生坯性能的影响，烧结温度对氮化硅陶瓷相对密度、弯曲强度和微观形貌的影响，以及氮化硅陶瓷的高温强度性能。结果表明：黏结剂含量为7%(质量分数)时，可制得干燥收缩均匀、表面光滑、无微裂纹的陶瓷管材生坯；烧结温度在1 740℃时，氮化硅陶瓷的相对密度和弯曲强度达到最大值，分别为96%和(684±23) MPa,其1 200℃时的弯曲强度达(380±21) MPa,具有良好的高温强度性能。     

重结晶碳化硅材料的制备与应用研究进展

从原料纯度及颗粒形状、成型方法、烧结温度及烧结气氛等方面阐述了重结晶碳化硅材料的制备工艺及其特点,并与其他组成或性能相近的碳化硅材料做了对比;介绍了重结晶碳化硅材料的组成、结构与性能特点,重点介绍了重结晶碳化硅材料在高温强度、抗氧化性等方面的研究,并概述了重结晶碳化硅材料在高温窑具、柴油车尾气净化器等领域的应用情况。     

高性能改性腐植酸制备烟煤型煤实验研究

为提高烟煤型煤机械强度,以加工后的腐植酸为黏结剂制备烟煤型煤,采用单因素实验和正交实验研究了加热时间、Na OH质量分数、黏结剂加入量、加热温度对腐植酸烟煤型煤抗压强度和跌落强度的影响。结果表明:利用腐植酸制备的烟煤型煤具有良好的机械强度,粉煤成型率较高。影响腐植酸烟煤型煤机械强度的主要因素是黏结剂加入量,其次为Na OH质量分数、加热温度、加热时间。烟煤型煤制备的最佳工艺条件为:加热时间130 min,Na OH质量分数6%,加热温度90℃,黏结剂加入量15%,此时型煤抗压强度为1620.2 N/个、跌落强度为99.0%。利用改性腐植酸可制备出适用于工业生产的烟煤型煤。     

助剂对高温锰基脱硫剂脱硫性能的影响

脱硫剂中加入助剂不仅可以提高脱硫剂的耐久性和机械强度,还可以提高其化学稳定性.采用机械混合法制备了锰铜脱硫剂,通过XRD,SEM和BET等手段研究了助剂对脱硫剂的结构、物相及比表面积的影响.并在固定床反应器中考察了助剂对脱硫剂脱硫性能的影响.实验结果表明,活性组分锰铜摩尔比为9:1,黏结剂选用10%自制溶胶来代替矿物黏结剂制备得到的脱硫剂有较好的脱硫性能,脱硫精度最高可达8×10-6,硫容量可达33.1%.助剂的加入可以改善脱硫剂的脱硫性能.     

碳化钼催化剂的制备及应用研究进展

碳化钼因其具有类贵金属性质和耐焙烧、耐硫耐氮、高熔点等优点,使其在催化领域中得到了广泛的关注。分析了制备过程中碳源、升温速率、不同碳源浓度、碳化终温和碳化钼制备方法对碳化钼的结构及催化性能的影响,并对其在加氢反应、制氢反应、氧化还原反应中的应用进行了综述。     

聚丙烯腈纤维的氧化碳化工艺

主要研究了氧化温度、氧化牵伸、碳化牵伸对最终碳纤维性能的影响,结果表明:氧化一区温度适中,可以避免纤维形成皮芯结构,从而制备强度较高的碳纤维;氧化一区施加适当的牵伸,可保持纤维取向,从而制备较高强度的碳纤维;碳化过程中,对低温碳化阶段施加适当的正牵伸,高温碳化阶段施加一定的负牵伸,能够提高碳纤维的力学性能。     

煤沥青材料的应用及其发展前景

煤沥青分为低温、中温、高温煤沥青。介绍了煤沥青的种类与性能,论述了中温煤沥青作为基础材料用作黏结剂、浸渍剂、碳纤维、涂料,道路沥青等的应用,讨论了煤沥青用作石墨电极、电炭、防腐材料、结构材料、燃料油以及在道路沥青方面的发展前景。     

CO2 separation by carbon molecular sieve monoliths prepared from nitrated coal tar pitch

The objective of the present work is to develop a simple procedure, which avoids the need of a binder, to obtain activated carbon monoliths from a waste precursor (coal tar pitch) suitable for CO₂ capture and/or separation. The main task of this process consists of a nitration process of the coal tar pitch. This nitration step over the coal tar pitch is characterised by different techniques, such as infrared spectroscopy and thermogravimetric analysis. The nitration treatment produces the oxidation of the pitch molecules, leading to hydrogen consumption and generating oxygenated and nitrogenated surface complexes. As a consequence of this oxidation, nitrated coal tar pitch is an infusible material, which allows the carbonization of monolithic pieces avoiding their fusion. Decomposition of these surface complexes during the carbonization of monoliths generates narrow microporosity, which is suitable for CO₂ capture from gas streams at room temperature. The molecular sieving properties of these materials are studied by CH₄ and CO₂ adsorption kinetics.     

Effect of densification parameters on the low-energy tribological behavior of carbon/carbon composites

The low-energy tribological behavior was investigated in carbon/carbon composites fabricated by processing with different densification parameters. In the densification process, different impregnating precursors and carbonization temperatures were used to investigate the influence on physical and mechanical properties, microstructure and tribological behavior. Experimental results indicate that the density and hardness of resin-based specimens are higher than those of pitch-based specimens after four densification cycles. When increasing carbonization temperature in the specimens based on coal tar pitch, the open porosity increases whereas both the bulk density and the hardness decrease. When comparing the tribological properties of the specimens with different impregnating precursors, coal tar pitch specimens show lower and more stable friction coefficients and exhibit lower weight losses. This is because the pitch matrix is transferred to the preferred orientation structure carbon after carbonization. The different carbonization temperatures do influence the tribological properties; specimens carbonized at 700 °C exhibit the lowest weight loss and the most stable friction coefficient.     

Utilisation of the binders prepared from coal tar pitch and phenolic resins for the production metallurgical quality briquettes from coke breeze and the study of their high temperature carbonization behaviour

To reduce the cost of the formed coke briquettes which can be used as a substitute fuel to the metallurgical coke for the blast furnace from the coke breeze alternative binders and their blends were used. The high temperature behavior was investigated. The binders tested were: the nitrogen blown, air blown coal tar pitch and the blend of air blown coal tar pitch with the phenolic resins blends. The phenolic resin blends were prepared by mixing equal amount of resole and novalac. From the results, nitrogen blowing resulted in the weakest briquettes. The air blowing procedure should be preferred in place of nitrogen blowing for this purpose. When the air blown coal tar pitch was used alone as a binder, the briquettes must be cured at 200 °C for 2 h, then carbonized at a temperature above 670 °C. Since it requires higher temperature at carbonization stage, using air blown coal tar pitch alone as a binder was not economical. Therefore, the briquettes were prepared from the blended binder, containing air blown coal tar pitch and phenolic resins blend. The optimum amount of air blown coal tar pitch was found to be 50% w/w in the blended binder. Curing the briquettes at 200 °C for 2 h was found to be sufficient for producing strong briquettes with a tensile strength of 50.45 MN/m². When these cured briquettes were carbonized at temperatures 470 °C, 670 °C and 950 °C, their strength were increasing continuously, reaching to 71.85 MN/m² at the carbonization temperature of 950 °C. These briquettes can be used as a substitute for the metallurgical coke after curing; the process might not require un-economical high temperature carbonization stage.     

Improvement in the quality of self-firing anodes of aluminum electrolyzers and other carbon articles

An effective method is demonstrated for improving the quality of carbon materials and graphite, whose articles are used extensively in different branches of the national economy. This method with use of the “nudel process” includes preparation of a strong and compact filler. The low temperature for filler preparation (550°C) provides a synchronous nature for its shrinkage with the binder during subsequent heat treatment, which reduces to a minimum structural defects for the final material, and as a consequence, it considerably increases the physicomechanical and operating properties similar to the properties of normal high quality materials, and the level of quality for the latter is achieved by repeated production cycles of impregnation of coal tar medium-temperature pitch, i.e. firing. The operational properties of articles made from the material exceeds the similar properties of articles made from traditional materials. The marked production advantages of the suggested version for carbon material using the nudel process are a significant reduction in the time of graphite preparation, a reduction of discharge into the atmosphere of cancerous substances (pitch vapors) and carbon dust; reduced gas flow rate, electric power, spilled materials, and other material expenditures. __________ Translated from Novye Ogneupory, No. 8, pp. 37–40, August 2007.     

大直径中间相沥青基炭纤维的制备研究

以萘系中间相沥青为原料,通过熔融纺丝和随后的预氧化、炭化以及石墨化处理制备了中间相沥青基圆形炭纤维.研究了热处理温度对纤维导电性能和力学性能的影响,并采用红外光谱仪、元素分析仪、扫描电子显微镜和X射线衍射仪对纤维的组成、形貌和微观结构进行了表征.研究结果表明：纤维在预氧化时形成的羟基、酰基等含氧官能团在随后的炭化、石墨化处理过程中消失;随热处理温度的升高,石墨微晶逐渐发育、长大,并沿纤维轴向高度取向,纤维的电阻率不断降低,力学性能不断增强;3 000℃石墨化纤维电阻率为1.3μΩ·m,对应的强度和模量值为1.6GPa和380 GPa.     

Evaluating multi-step oxidative stabilization behavior of coal tar pitch-based fiber

Oxidative stabilization is an important step for isotropic pitch-based carbon fiber preparation; coal tar pitch-based fiber is treated by multi-step oxidative stabilization under various conditions to investigate the oxidative stabilization mechanism. The chemical structure changes of isotropic pitch-based fiber during the oxidative stabilization and carbonization stage are systematically characterized by In-situ diffuse reflectance infrared Fourier transform, elemental analysis, mass spectroscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance, scanning electron microscope with an energy dispersive X-ray spectrometer. These results show that the oxygen distribution gradient in oxidative stabilized fiber radial direction become homogeneously with the increasing of oxidation temperature and time under multi-step oxidative stabilization. The resultant carbon fiber shows tensile strength of 942 ± 42 MPa and Young's modulus of 42.8 ± 3.1 GPa due to appropriate oxygen content, homogeneous oxygen distribution, more cross-link bond (C-O-C) content, higher aromaticity and lower weight loss introduced in multi-step oxidative stabilized pitch fiber. The multi-step oxidative stabilization provides synergy effect between reaction rate and the oxygen diffusion rate as well as eliminates the oxygen concentration gradient, it provides an time-saving and energy-effective method for the oxidative stabilization of isotropic pitch-based carbon material (pitch fiber, pitch microsphere, etc.) and improve the resultant carbon material performance.     

高性能沥青基碳纤维制造——氧化碳化石墨化

本文论述了用于制造高性能碳纤维的中介相沥青初生纤维的氧化稳定化、碳化与石墨化过程及其对最终碳纤维力学性能与电导性能的影响;讨论了氧化碳化与石墨化温度、升温速率、中介相沥青原料种类与氧化稳定化程度、石墨化程度、抗张强度与模量、电阻率、纤维结构的关系;指出了五种加速氧化稳定化进程的有效措施。     

制备工艺对炭/石墨密封材料性能及其结构的影响

以改性的填料（二次焦）为骨料炭,中温煤沥青为黏结剂来制备炭/石墨密封材料,考察了材料制备工艺条件对材料机械强度、开孔率以及微观结构的影响。研究表明,与传统的炭/石墨密封材料制备工艺相比,利用改性后的骨料炭所制备的炭/石墨材料具有较高的机械强度和相对均匀的孔径分布。此外,随着二次焦热处理温度的升高,最终材料的体积密度和机械强度增大,开孔率降低。当二次焦热处理温度升高到540℃时,最终所得材料的抗压和抗弯强度分别达到210.0MPa和67MPa,开孔率为19.3%。炭/石墨材料经浸渍金属Cu后,Cu颗粒在利用传统工艺制备的材料中的尺寸相对较大,且存在局部聚集或团聚,而在利用二次浆涂工艺制备的材料中则呈细网状结构且均匀分布。     

复合粘结剂炭素材料性能研究

用自制凝胶一沥青作复合粘结剂制备了炭素材料。通过测定不同配方、焙烧温度下试样的物理性能,认为9~#配方试样具有较好的导电性能和较高的抗压强度,沥青用量只有20%,明显低于传统炭素材料沥青用量。结果表明,凝胶一沥青复合粘结剂与石油焦粘结性能好,改变了传统的热压成型工艺。