共查询到19条相似文献,搜索用时 140 毫秒
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在中等强度驻波声场中,对燃煤可吸入颗粒物进行团聚清除实验研究。系统研究声场频率、声压级、可吸入颗粒质量浓度及颗粒在声场中的停留时间对团聚清除效率的影响。实验结果表明:颗粒在声场中团聚的最佳声波频率为1 416 Hz;声压级越高越有利于颗粒的团聚,声压为128 dB时颗粒质量清除效率高达27.8%;可吸入颗粒质量浓度增大,颗粒清除效率降低;颗粒在声场停留时间为9—11 s时,团聚清除效率达到最大值。颗粒粒径影响声波团聚过程,粒径1.1μm与4.7—10μm颗粒的清除效率高于1.1—4.7μm颗粒的清除效率。 相似文献
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超细氧化钇粉体的制备 总被引:15,自引:0,他引:15
湿化学法制备超细粉体时,反应、分离、干燥以及灼烧都不同程度地影响粉体的粒径及团聚。在传统的草酸沉淀法制备氧化钇基础上对溶液的浓度、pH值以及表面活性剂的选择和用量、颗粒的表面电位进行了考察研究,确定了反应过程中影响粉体粒径的各个因素,得到一次粒径50-100nm,平均粒径0.521μm,晶型良好且具有单分散趋势的超细氧化钇。 相似文献
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本文实验测试不同浓度TiO2悬浮液的相关参数,包括颗粒粒径、电导率、介电常数、表面电势、颗粒的Zeta电势等,计算了不同浓度悬浮液颗粒间作用势能,分析了颗粒团聚机理及悬浮液的稳定性.用光学显微镜观察不同浓度悬浮液团聚体的形貌.在此基础上,从团聚体的自相似性、实验获得团聚体的形貌出发,分析了团聚体的分形特征,并用分形软件计算了不同浓度悬浮液团聚体的分形维数. 相似文献
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以工业浓缩钛液为原料,采用外加晶种水解工艺制备金红石型二氧化钛,考察了晶种不同添加量对水解率、一次团聚粒子、煅烧二氧化钛晶体形貌以及一次团聚粒子粒径与颜料性能亮度的关系。结果表明,当水解晶种添加量为钛液所含二氧化钛质量的3.0%时,硫酸氧钛的水解率高达95.4%,一次团聚粒子粒径约为43 nm,煅烧二氧化钛呈短圆柱状,此时亮度为94.4。说明外加晶种在引发硫酸氧钛水解的同时,影响原级粒子间的相互作用,降低了一次团聚粒子的平均粒径,并影响了一次团聚粒子的再团聚,从而降低了一次团聚粒子的再团聚倾向。在此条件下,煅烧后二氧化钛的粒径减小、粒径分布更为均匀,进而提高了煅烧二氧化钛的亮度,改善了其颜料性能。 相似文献
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通过实验研究了低频下燃煤飞灰的声波团聚。燃煤飞灰气溶胶在声波作用下粒径分布发生明显变化,大量细颗粒团聚产生粗颗粒,气溶胶浓度降低。在147 dB、1400 Hz时,气溶胶总浓度和PM2.5浓度分别减少了68.4%和75.6%,达到很好的团聚效果。从扫描电镜照片中可以观察到声波团聚过程中产生了粒径大于10 μm的链状团聚体。在声波作用下,气溶胶总浓度随团聚时间呈指数衰减规律降低。实验证明了声波团聚中存在最佳频率,在此频率下团聚效果最好,偏离该值团聚效果急剧降低。另外,实验发现最佳频率随声压级的增大而轻微降低。同时,研究了声压级、停留时间和气溶胶初始浓度等参数对声波团聚的影响。 相似文献
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随着钛白粉行业的快速发展,硫酸法生产工艺对分离设备的要求也越来越高。为满足市场需求,公司研发了新型LWLC450×1250螺旋卸料沉降-过滤离心机,并将其应用在硫酸法钛白粉生产中。结果表明:离心机分离出的液相含钛总质量浓度大于160 g/L,固体含钛质量分数小于0.41%,大大提高了钛液的质量和收率,同时能有效节能降耗,改善工作环境,是钛白粉行业理想的分离设备。 相似文献
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The process of ammoniac precipitation of hydrated titanium dioxide from a solution of ammonium hexafluorotitanate obtained during ilmenite processing by ammonium fluoride with the further sublimation separation of titanium tetrafluoride has been studied. The dehydration of hydrated titanium dioxide has been studied. The phase structure of titanium dioxide, depending on the thermal treatment and precipitation conditions, has been investigated. The size of the sample particles has been studied with the method of electron microscopy. The conditions of rutile and anatase pigments production have been determined. 相似文献
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Background
Nanoparticles are characterized by having a high surface area per mass. Particulate surface area has been reported to play an important role in determining the biological activity of nanoparticles. However, recent reports have questioned this relationship. This study was conducted to determine whether mass of particles or surface area of particles is the more appropriate dose metric for pulmonary toxicity studies. In this study, rats were exposed by intratracheal instillation to various doses of ultrafine and fine carbon black. At 1, 7, or 42 days post-exposure, inflammatory and cytotoxic potential of each particle type was compared on both a mass dosage (mg/rat) as well as an equal surface area dosage (cm2 of particles per cm2 of alveolar epithelium). In an additional study, the pulmonary responses to instillation of ultrafine carbon black were compared to equivalent particle surface area doses of ultrafine titanium dioxide. 相似文献17.
Lili Wang Xiaying Jiang Chenglong Wang Yi Huang Yiding Meng Jianzhong Shao 《Coloration Technology》2020,136(1):15-22
To improve the properties of titanium dioxide particles and realise their firm anchorage in blue light curing film, three modified titanium dioxide particles were prepared by grafting 3‐(trimethoxysilyl)propyl methacrylate, 3‐aminopropyltriethoxysilane and hexadecyltrimethoxysilane. The surface changes of titanium dioxide particles after modification were characterised. The dispersion stability, photo‐polymerisation, rheological and mechanical properties of modified titanium dioxide blue light curing inks were investigated. Results showed that compared with native titanium dioxide, modified titanium dioxide particles were more appropriate for blue light curing ink. The particle sizes of the three modified titanium dioxide particles became smaller, their surfaces exhibited hydrophobicity, and the viscosity of the modified titanium dioxide inks decreased slightly. Of the three modified titanium dioxide particles, 3‐(trimethoxysilyl)propyl methacrylate‐ and hexadecyltrimethoxysilane‐modified titanium dioxide particles exhibited better dispersion stability in blue light curing ink. In particular, 3‐(trimethoxysilyl)propyl methacrylate‐modified titanium dioxide blue light curing ink showed the best photo‐polymerisation and mechanical properties, which indicated the participation of the pigment grafted by double bonds in the blue light curable polymerisation. Using modified titanium dioxide in blue light curing ink, the dry/wet rubbing fastness of the printed fabrics improved. 相似文献
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以凹土代替部分二氧化钛制备涂料,通过改变凹土的用量测定涂料的性能,同时做了凹土进行超细粉碎处理前后对涂料的影响对比。凹土替代二氧化钛,不但降低涂料成本还可以改善涂料的某些性能,但用量不宜太多,与适量的碳酸钙混合使用较好。相同的代替量,超细凹土优于原粉凹土。 相似文献
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以含钛铁精矿直接还原冶炼的含钛物料(深还原钛渣)为原料,对硫酸法制取颜料级钛白粉的工艺进行了研究。实验结果表明,深还原钛渣具有良好的酸解性能,酸解率可达97%;酸解后得到的钛液过滤性能好;但酸解钛液中氧化镁和氧化铝浓度过高,所以直接以该钛液为原料制得的钛白颜料性能差。采用深还原钛渣和钛精矿按一定比例混合酸解,可以避免钛液杂质含量过高对最终钛白产品质量造成的影响。深还原钛渣较佳用量为不高于钛原料总质量的20%。 相似文献