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Weining Xie Yaqun He Hong Li Yu Zhang Xiangnan Zhu 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2018,40(4):446-452
Raw coal was ground in a Hardgrove mill, and mineral liberation from coal was investigated by float-sink test and electron probe microanalyzer (EPMA). Based on EPMA, associated conditions of mineral were determined. Analyses of energy-size reduction show that energy efficiency decreases with time. For +0.074 mm progenies, yields of particles in ?1.5 g.cm?3 decrease with the increase of size and time, and products in +1.8 g.cm?3 show the opposite trend. EPMA of 0.25–0.125 mm, 1.5–1.8 g.cm?3 products ground for 10 min indicates that only part of minerals are liberated. For ?0.074 mm products, the yield of particles in ?1.5 g.cm?3 decreases by 23.36% in last several minutes, but ash content of +1.8 g.cm?3 also decreases by 13.18%. Since breakage of raw coal in last 9 min does not reduce particle size obviously, and liberation degree cannot be improved dramatically, closed grinding of 10 min in Hardgrove mill is proper to balance the size reduction and mineral liberation. 相似文献
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Kai Li Tengteng Lyu Junyi He Ben W. L. Jang 《Frontiers of Chemical Science and Engineering》2020,14(6):929
Five hundred ppm Pd/CeO2 catalyst was prepared and evaluated in selective hydrogenation of acetylene in large excess of ethylene since ceria has been recently found to be a reasonable stand-alone catalyst for this reaction. Pd/CeO2 catalyst could be activated in situ by the feed gas during reactions and the catalyst without reduction showed much better ethylene selectivity than the reduced one in the high temperature range due to the formation of oxygen vacancies by reduction. Excellent ethylene selectivity of ~100% was obtained in the whole reaction temperature range of 50°C–200°C for samples calcined at temperatures of 600°C and 800°C. This could be ascribed to the formation of PdxCe1−xO2−y or Pd-O-Ce surface species based on the X-ray diffraction and X-ray photoelectron spectroscopy results, indicating the strong interaction between palladium and ceria. 相似文献
85.
Xingbang Li He Zhong Jingxian Zhang Yusen Duan Jingjing Li Dongliang Jiang 《International Journal of Applied Ceramic Technology》2020,17(3):844-853
Zirconia ceramics have shown a wide applicable prospect in dental prosthetics because it possesses excellent mechanical performance and biocompatibility. The rheological behavior and curing properties of zirconia stereolithography slurry were studied, as well as the microstructure of the green, pyrolyzed, and sintered body. Variquat CC-42 NS was proved to be effective for zirconia powder dispersing in photocurable resin (SP-RC700). The curing characteristic of slurry showed that the depth of penetration tended to increase with the solid loading. Finally, the zirconia all-ceramic crowns were fabricated via DLP-based stereolithography printer. Results showed that the particles were evenly distributed in the cured resin matrix without obvious agglomeration, and the interlayered structure disappeared after binder burnout. The sample with a major crystalline phase of tetragonal zirconia and a porosity of 10(1)% were obtained after sintering at 1550°C. 相似文献
86.
建设工程配套石料矿山相比传统以取得矿产品为目的的采石场具有周边环境复杂、施工强度高、全寿命周期短、工程质量要求灵活多变、爆破安全警戒工作量大等特点。以普陀区六横岛中远船务二期工程石料(宕渣)矿爆破开采工程为例,介绍了该类矿山开采爆破的设计施工技术要点及施工经验,有效解决了建设工程配套小型石料矿山复杂环境开采爆破存在的一些问题,对于类似工程实践有一定的借鉴价值。 相似文献
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