共查询到19条相似文献,搜索用时 111 毫秒
1.
叙述了通过717强碱阴离子交换树脂分离铬,采用控制酸度使锆与铝分离,然后用苦杏仁酸掩蔽钛,再加过量EDTA,在弱酸性溶液中铝与EDTA络合,以二甲酚橙为指示剂,用氟化铵置换-EDTA络合滴定法测得Al2O3量的过程,论证了这种测定方法的准确性和可行性。 相似文献
2.
刚玉砖和铬刚玉砖的应用 总被引:1,自引:0,他引:1
刚玉砖及铬刚玉砖是石化行业造气炉和反应炉的关键耐火衬里材料。本文介绍了国产刚玉砖及铬刚玉砖的力学性能及其在石化行业气化炉和反应炉上的应用情况。结果表明 ,刚玉砖及铬刚玉砖主要理化性能和使用效果达到或超过同类引进产品 ,完全可以替代进口材料 ,满足了石化行业的生产需要 相似文献
4.
5.
提高电熔锆刚玉砖质量的方法邓延钦(江油市玻璃耐火材料厂621700)目前我国已有20多家专门生产电熔锆刚玉砖的厂家,产量基本上满足了国内市场的需要,部份代替进口产品。但与国外先进水平相比,产品质量仍有一定差距。一、主要原材料的选择生产优质电熔锆刚玉砖... 相似文献
6.
优质熔铸33~#锆刚玉砖的研制毛利民(中国建筑材料科学研究院耐火材料科学研究所100024)TheDevelopmentofHighGradeFused-Cast33#AZSRefractory¥MaoLimin(ResearchInstituteo?.. 相似文献
7.
8.
9.
阐述了熔铸锆刚玉砖的材料和生产特点及树脂砂造型工艺在熔铸锆刚玉砖生产中的优点和容易出现的问题,对如何改进树脂砂造型工艺在熔铸锆刚玉砖生产中的应用和提高熔铸锆刚玉砖产品质量和外观色泽进行了探讨。 相似文献
10.
11.
In the present work, a comparative study on the deactivation behavior of three types of industrial hydrotreating catalysts, namely, Mo/Al2O3, Ni–Mo/Al2O3 and Ni–MoP/Al2O3, that are used to promote primarily hydrodemetallization (HDM), hydrodesulphurization (HDS) and hydrodesulphurization + hydrodenitrogenation (HDS/HDN) reactions, respectively, in the first, second and third reactor of commercial atmospheric residue desulfurization (ARDS) units was carried out. The main objective of the study was to contribute to a better understanding of the relationship between catalyst type and catalyst deactivation patterns. The used catalysts from these experiments were fully characterized to determine the extent and the cause of deactivation. Special emphasis was paid to understanding the nature of the coke and metal deposition on the used catalysts by applying chemical analysis and various advanced analytical techniques, such as solid-state carbon-13 nuclear magnetic resonance spectroscopy (13C NMR), temperature-programmed oxidation (TPO), electron probe micro-analysis (EPMA), and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The results are discussed scientifically based on the physico–chemical properties of the three catalysts. 相似文献
12.
The effect of Al2O3 on mechanical properties of Ti3SiC2/Al2O3 composite fabricated by SPS was studied systematically. The results show that the hardness of the Ti3SiC2/Al2O3 composite can reach 10.28 GPa, 50% higher than that of pure Ti3SiC2. However, slight decrease in the other mechanical properties was observed with Al2O3 addition higher than 5–10 vol.%, which is believed to be due to the agglomeration of Al2O3 in the composite. 相似文献
13.
Wenguang Zhang Weimin Liu Chengtao Wang 《Journal of the European Ceramic Society》2002,22(16):2869-2876
Thin films of Al2O3 and doped Al2O3 were prepared on a glass substrate by dip coating process from specially formulated ethanol sols. The morphologies of the unworn and worn surfaces of the films were observed with atomic force microscope (AFM) and scanning electron microscope (SEM). The chemical compositions of the obtained films were characterized by means of X-ray photoelectron spectroscopy (XPS). The tribological properties of obtained thin films sliding against Si3N4 ball were evaluated and compared with glass slide on a one-way reciprocating friction tester. XPS results confirm that the target films were obtained successfully. The doped elements distribute in the film evenly and exist in different kinds of forms, such as oxide and silicate. AFM results show that the addition of the doped elements changes the structure of the Al2O3 films, i.e., a rougher and smoother surface is obtained. The wear mechanisms of the films are discussed based on SEM observation of the worn surface morphologies. As the results, the doped films exhibit better tribological properties due to the improved toughness. Sever brittle fracture is avoided in the doped films. The wear of glass is characteristic of brittle fracture and severe abrasion. The wear of Al2O3 is characteristic of brittle fracture and delamination. And the wear of doped Al2O3 is characteristic of micro-fracture, deformation and slight abrasive wear. The introduction of ZnO is recommended to improve the tribological property of Al2O3 film. 相似文献
14.
Antonio Licciulli Vincenzo ContaldiSanosh Kunjalukkal Padmanabhan Avinash BalakrishnanCristina Siligardi Daniela Diso 《Journal of the European Ceramic Society》2011,31(3):385-389
The present work describes the processing of alumina fiber reinforced alumina ceramic preforms consisting of chopped Al2O3 fibers (33 wt%) and Al2O3 (67 wt%) fine powders by slip casting. The preforms were pre-sintered in air at 1100 °C for 1 h. A lanthanum based glass was infiltrated into these preforms at 1250 °C for 90 min. Linear shrinkage (%) was studied before and after glass infiltration. Pre-sintered and infiltrated specimens were characterized by scanning electron microscopy, energy dispersive X-ray, X-ray diffraction, porosimetry and flexural strength. The alumina preforms showed a narrow pore size distribution with an average pore size of ∼50 nm. It was observed that introducing Al2O3 fibers into Al2O3 particulate matrix produced warp free preforms with minor shrinkage during pre-sintering and glass infiltration. It was observed that the infiltration process fills up the pores and considerably improves the strength and reliability of alumina preform. 相似文献
15.
This study investigates the effect of the incorporation of alumina particles on the thermomechanical properties of polybutylene succinate (PBS)/Al2O3 composites. The alumina surface was modified with the carboxylic groups of maleic acid through simple acid-base and in situ polymerization reactions. Scanning electron microscope (SEM) results revealed the introduction of maleic acid treated alumina significantly affect the morphology of the PBS/Al2O3 composites as compared to the neat PBS. The thermal conductivity of the composite (0.411?W?m?1 K?1) was more than twice that of neat PBS. The composite containing polymerization-modified alumina showed a 50% increase in storage modulus compared with that of neat PBS. In addition, universal testing machine (UTM) and differential scanning calorimetry (DSC) measurements indicated an increase in the tensile strength and degree of crystallinity after the incorporation of modified alumina in the PBS/Al2O3 composite. 相似文献
16.
S. Dejonghe R. Hubaut J. Grimblot J. P. Bonnelle T. Des Courieres D. Faure 《Catalysis Today》1990,7(4):569-585
The toluene hydrogenation performances of Mo--- and NiMo---Al2O3 hydrotreating catalysts are modified by vanadium deposited through HDM of the Vanadylporphyrin. Bulk deposited vanadium sulfide of mean VS1.1 stoichiometry does not greatly affect the intrinsic performances of the initial catalysts but it appears that a part of the deposited vanadium replaces Ni in the NiMoS phase and acts as a promoter of the supported MoS2 相似文献
17.
Al2O3/Cu-O composites fabricated by pressureless infiltration of paper-derived Al2O3 porous preforms
Stefan Pfeiffer Hannes Lorenz Zongwen Fu Tobias Fey Peter Greil Nahum Travitzky 《Ceramics International》2018,44(17):20835-20840
Al2O3/Cu-O composites were fabricated from the paper-derived alumina matrix infiltrated with a Cu-3.2?wt% O alloy. Paper-derived alumina preforms with an open porosity ranging from ~ 14 to ~ 25?vol% were prepared by sintering of alumina-loaded preceramic papers at 1600?°C for 4?h. Pressureless infiltration at 1320?°C for 4?h of the preforms with Cu–O alloy resulted in the nearly dense materials with good mechanical and electrical properties, e.g. fracture toughness up to 6?MPa?m0.5, four-point-bending strength up to 342?MPa, Young's modulus up to 281?GPa and electrical conductivity up to 2?MS/m depending on the volume fraction of copper alloy in the composites. The technological capability of this approach was demonstrated using prototypes in various engineering fields fabricated by lamination, corrugating and Laminated Object Manufacturing (LOM) methods. 相似文献
18.
Xiaohui Zhao Shuai Yan Hongmin Wang Hongchuan Jiang Wanli Zhang 《Ceramics International》2019,45(1):247-251
The oxidation-resistance of thin film sensors, particularly at high temperatures, is critical for the lifetime and performance of the sensor. The preparation and oxidation-resistance of an Al2O3/ZrBN-SiCN/Al2O3 composite film with a sandwich-structure was performed using reactive magnetron sputtering. The microstructure evolution of the composite film is examined herein using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analysis. Oxygen diffusion was significantly inhibited by the formation of crystalline Al2SiO5 and Zr-B-C amorphous phase inside the composite film. The Pt-13%Rh/Pt thin film thermocouple (TFTC) with the Al2O3/ZrBN-SiCN/Al2O3 composite film as a protective layer was fabricated and calibrated. Both the stability and lifetime of the TFTC was significantly enhanced for temperatures up to 1000?℃. The test error of the TFTC was reduced by half, compared with that of the TFTC with the Al2O3 protective layer, indicating an excellent oxidation-resistant performance of the composite film. 相似文献