共查询到18条相似文献,搜索用时 200 毫秒
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研究了以铝合金表面处理工业废渣为原料制备Al(OH)3的工艺,探讨了NaOH浸提Al和H2SO4法沉淀制备Al(OH)3的过程,考察了碱酸浓度及用量、温度、时间等对制备过程的影响,采用正交实验确定了最佳工艺条件,分析了Al(OH)3产品的化学组成、形貌和质量. 结果表明,干燥废渣中Al含量为28.7%,以Al(OH)3晶体存在. 在加入的NaOH与废渣中Al(OH)3摩尔比为2.88:1、反应温度75℃、时间55 min的最佳浸提条件下,Al浸出率达97.5%. 在加入的H2SO4与浸提液中AlO2-摩尔比为(0.95~1.10):1及pH=5.5的最佳沉淀条件下,Al(OH)3的沉淀收率为89.2%,Al总回收率为87.1%. Al(OH)3产品为无定型白色粉末,粒径约为17 mm,纯度达95.5%. 相似文献
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以端乙烯基硅油为基胶、含氢硅油为交联剂、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)为表面处理剂、Al(OH)3或Al(OH)3/铂络合物为阻燃剂,制备阻燃型有机硅电子灌封胶。研究结果表明:对Al(OH)3表面进行处理、降低其粒径、增加其含量、Al(OH)3/铂络合物并用等均有利于提升灌封胶的阻燃性能;当w(KH-570)=0.5%[相对于Al(OH)3质量而言]、Al(OH)3的平均粒径为2.6μm、m(5.0μmAl2O3):m[2.6μm Al(OH)3]=160:40和w(铂络合物)=0.002%(相对于基胶质量而言)时,可制得阻燃性优异的有机硅电子灌封胶。 相似文献
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纳米Al2O3粒子的制备 总被引:18,自引:0,他引:18
以异丙醇铝Al(OPr^i)3(即Al(OCH(CH3)2)3)为原料,用醇盐水解法制备纳米氧化铝粒子,比较系统地研究了制备条件(加水方式,反应物配比,浓度,溶剂等)对产物粒子颗粒大小的影响,采用TEM,X射线衍射等技术对所得产品性能进行了表征,实验结果表明,纳米Al2O3粒子分散性好,粒径在20-100nm之间,颗粒的形状和尺寸随反应条件的不同而变化。 相似文献
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甲醇分解铝酸钠溶液制备大颗粒氢氧化铝的工艺与表征 总被引:1,自引:0,他引:1
对甲醇分解NaAl(OH)4溶液制备大颗粒Al(OH)3进行了工艺研究,考察了分解温度、分子比(Na2O/Al2O3摩尔比)、Na2O浓度、硅量指数(Al2O3/SiO2质量比)、搅拌速度和甲醇用量对产品粒度和形貌的影响. 结果表明,在NaAl(OH)4溶液的Na2O浓度为180 g/L、分子比为1.5~1.6,硅量指数550以上及甲醇与NaAl(OH)4溶液等体积的优化条件下,控制分解温度60℃,可得到平均粒径达80 mm的球形Al(OH)3. 甲醇的加入改变了Al(OH)3生长基元的径向和轴向生长速率,甲醇量越大,径向生长速率越快,生长基元越薄. 当甲醇与NaAl(OH)4溶液体积比为1:1时,Al(OH)3生长基元的厚度在100 nm左右. 随分解温度升高,Al(OH)3由Bayerite型向Gibbsite型转变,热重-差热值与理论值吻合. 相似文献
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为了获得具有良好红外吸收特性及低发射率复合颜料,通过将纳米NiO复合于片状金属铝粉表面的方法,获得了复合效果好的纳米NiO/Al复合粒子.为了保证复合物的红外伪装性能,通过对复合前驱体Ni2CO3(OH)2/Al的热分析,确定了对复合物的热处理温度.通过对复合物热处理前后的电镜照片分析,发现热处理前复合物表面是由线状的Ni2CO3(OH)2交织而成的,而热处理后则变成了由纳米球状NiO粒子连接而成的球链.这种现象在同类研究中尚未见报道.对比所制备的纳米NiO/Al和NiO的XRD图谱,发现纳米NiO/Al中的NiO衍射峰宽化,表现出纳米粒子的特征,由半高宽计算出其晶粒粒径为12 nm. 相似文献
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采用溶析结晶法制备了球形聚苯乙烯(PS)亚微米粒子,并用激光粒度仪、FESEM等分析方法对粒子大小、粒度分布以及粒子形貌等进行了表征,对料液浓度、搅拌速度、料液/反溶剂体积比、结晶温度对粒径的影响进行了考察.结果表明,溶析结晶法制备的PS粒子为球形,粒径分布比较窄,平均粒径在500nm左右,比文献报道的超临界流体技术法制备的PS颗粒小;料液浓度是影响粒径的重要因素,其他因素对粒径影响较小. 相似文献
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以氨气和硝酸锌为原料,在旋转填料床中通过气液反应制备前驱体氢氧化锌.经煅烧后可得超细氧化锌粒子,经XRD和FEM检测得到其粒径为20-80nm。重点研究旋转填料床转速、原料浓度、氨气分率、气液比等对前驱体氢氧化锌粒径的影响,选择洗涤条件及优化煅烧温度和时间.确定了旋转填料床气液反应制备超细氧化锌的最佳工艺条件。 相似文献
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Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor. The effects of Ca(OH)2 concentration, CO2 pressure and liquid flow velocity on the particles morphology, pressure drop and membrane fouling were studied. With rising Ca(OH)2 concentrations, the average size of the particles increased. The effects of Ca(OH)2 concentration and CO2 pressure on particles were not apparent under the experimental conditions. When the Ca(OH)2 concentration and liquid flow velocity were high, or the CO2 pressure was low, the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage, whereas the fouling was slight at exit. The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials. The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration. 相似文献
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The purpose of this study was to build a platform for producing fine particles by applying a high-gravity (higee) technique to achieve reactive precipitation. Barium carbonate was chosen as a model compound and was produced in a spinning disk reactor (SDR), which is one type of higee equipment, via a carbonation route and a once-through mode. For size measurement, a suitable dispersion method was developed to obtain reproducible particle size data, using a laser-light analyzer. Several factors that affected the particle size of barium carbonate, including the CO2 flow rate, the feed rate of Ba(OH)2 slurry, the rotation speed, and the solid-content of feed slurry, were investigated. A high rotating speed and low feeding rate of slurry yielded small particles. The optimum solid-content of feeding slurry for obtaining small particles was also determined. However, the effect of the CO2 flow rate on the particle size of the product was not significant. 相似文献
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Chun‐Sheng Fang Wei‐Zhuo Gai Zhen‐Yan Deng 《Journal of the American Ceramic Society》2014,97(1):44-47
A facile route was used to modify Al particle surfaces by putting Al particles into an Al(OH)3 suspension, which was produced by the reaction of Al powder with water under vacuum at a mild temperature, then drying and heat‐treating under vacuum at elevated temperature. The modified Al powder has a good reaction activity with water to generate hydrogen, and its reaction rate depends on the sizes of Al particles used to produce Al(OH)3 suspension. The reaction induction time of the modified Al powder prepared using the Al(OH)3 suspension produced by the reaction of Al with water is obviously shorter than that prepared using the Al(OH)3 suspension formed by the direct addition of a commercial Al(OH)3 powder, because the in situ formed Al(OH)3 has a finer microstructure. As the present method has no complicated processing procedure and the Al‐water reaction byproduct can be reused to modify Al, it is an economically viable way to fabricate the activated Al powder for commercial applications. 相似文献
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Al2O3陶瓷膜在过滤染料废水过程中容易被染料大分子堵塞,导致Al2O3陶瓷膜水通量下降。以钛酸丁酯、异丙醇铝为前驱体,采用溶胶-凝胶法制备Ti(OH)4-AlOOH复合溶胶,经450 ℃烧成获得TiO2-Al2O3复合粉体。以SEM、纳米粒度/电位仪作为主要表征手段,研究了不同Ti(OH)4和AlOOH摩尔比对复合溶胶粒径分布的影响,进而探究TiO2-Al2O3复合粉体的光催化性能。结果表明,Ti(OH)4和AlOOH摩尔比为0~0.4时,随着Ti(OH)4和AlOOH摩尔比的增大,胶粒的平均粒径从67.5 nm减小到34.0 nm,Ti(OH)4-AlOOH复合溶胶的电位从43 mV升高至53 mV。当Ti(OH)4和AlOOH摩尔比为0.4时,复合粉体对结晶紫的去除率高达79.3%,反应速率常数增大到了0.018 min-1。TiO2-Al2O3复合粉体制备的陶瓷膜能有效降解表面沉积的大分子,解决了陶瓷膜堵塞的问题。 相似文献
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选用粒径为15 μm的鳞片石墨和3 μm的氧化铝(Al2O3)为导热填料,采用新型同向非对称双螺杆挤出机为加工设备,在石墨填充量为10 %(质量分数,下同)而Al2O3填充量为10 %~50 %范围内,制备聚丙烯(PP)/Al2O3和PP/Al2O3/石墨导热高分子材料并进行性能测试。结果表明,添加少量石墨,在Al2O3填充量低时可增强导热高分子材料的拉伸强度,石墨与Al2O3的混杂减缓了拉伸强度下降的速率,改善了导热高分子材料的弯曲和冲击性能;PP/Al2O3/石墨的熔体流动速率比PP/Al2O3的小,PP/Al2O3/石墨比PP/Al2O3的负载热变形温度升高约15 %。 相似文献