作者: Yun Ha Yoo, Jung Gu Kim
摘要: Aqueous corrosion behaviors of Fe3Al-based iron aluminides were investigated. From the
result of cyclic anodic polarization tests conducted in 3.5 wt.% NaCl solution at 25, 48, 72 and
95°C, as the temperature increased, the resistance to pitting corrosion decreased significantly,
especially over the range of 25~48°C. From the result of crevice corrosion tests, no crevice
corrosion occurred on FAL-Mo in the lower chloride-containing solution (200 ppm Cl-), however,
FAL-Mo did not perform as well as the 304L SS in the higher chloride-containing solution (3.5
wt.% NaCl). From the result of anodic polarization tests performed in sulfur-compound solutions,
additions of Cr and Mo to the Fe3Al-based iron aluminides tend to improve the aqueous corrosion
resistance. Aqueous corrosion behaviors with different Al content evaluated by cyclic anodic
polarization test in the chloride-containing solution exhibited the more stable passive behavior and
the higher pitting resistance as Al contents increased.
23
作者: Dong Jin Wan, Dan Qu, Hua Xiao, Yong De Liu, Ting Lu, Wen Qing Xu
摘要: Hydrotalcites (HT-X) of different Mg/Al ratio (X is Mg/Al molar ratio, 3 and 4) was synthesized by co-precipitation method. Calcined HTLCs (CHT-X) at 500°C have been shown to recover their original layered structure by taking up chloride ion from aqueous solution. Adsorption of chloride by CHT-X was investigated in batch mode. The kinetics study showed that the pseudo-second-order kinetics model could be used to describe the adsorption process satisfactorily. The equilibrium isotherm showed that the Langmuir model gave a better fit to the experimental data than the Freundlich model. The maximum adsorption capacity of CHT-3 was 83.33 mg/g; CHT-4 was 90.09 mg/g .The samples of different Mg/Al ratio have different crystallite size, thus showing different adsorption capacity. As the Mg/Al ratio increases from 3 to 4; the electric charge density between the layers becomes weaker; the interlayer spacing increases; the sample shows greater adsorption capacity. The HT-X where characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX).
420
作者: Chun Sheng Ding, Xiao Yan Ma, Ying Long Zhou, Ping Ning
摘要: Ferric salt modified sands were prepared with quartz sand as a carrier and ferric salt coating by the two methods of repeat high-temperature process and repeat alkaline deposition process. The specific surface area of two ferric salt modified sands were detected, and their Pb2+ adsorption capability in different conditions were also described in this paper. The results showed that the specific surface area of ferric chloride and ferric nitrate modified sand was 2.468m2/g and 4.247m2/g respectively, which was 6.910 and 12.612 times more than that of raw quartz sand. In the neutral pH condition, the removal efficiency of Pb2+ by raw quartz sands was approximately 37%, in contrast, the removal efficiency reached 85% by ferric nitrate modified sand and over 90% by ferric chloride modified sand, and it was much higher than that of raw quartz sand.
852
作者: Yong Zheng Wang, Lei Jiang, Mao Zhen Yue, Su Fang Bian
摘要: In this paper, three detection methods were analyzed to determine the chlorine precipitation from the flue gas: Silver nitrate volumetric analysis (SNVA), Volhard method (VM) and Mercuric thiocyanate spectrophotometric method (MTSM). Results indicated that SNVA and VM were simple and convenient, but unsuitable for the detection of blend fuel due to the high lower limit. MTSM was suitable for biomass and coal co-combustion for its low lower limit and high sensitivity. In addition, MTSM needed less sample solution, which made it more suitable for multiple measurements to reduce errors, and the maximum proportional error was only 3.5%.
1423
