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The flotation separation of scheelite from calcite using sodium humate (SH) as a potential depressant has been studied through micro-flotation experiments, zeta potential and Fourier transform infrared (FT-IR) spectra measurements. The flotation results indicate SH exhibited selective depression effect on calcite in the presence of sodium oleate, achieving the flotation separation of scheelite from calcite. Zeta potential results indicate that SH strongly absorbed on calcite surface but negligibly on scheelite surface, which prevents the adsorption of sodium oleate on calcite surface. The FT-IR results also show that SH can be adsorb on the surface of calcite. Results shown a higher Ca density on the calcite than on scheelite surface, and that calcite can accommodate the interaction of SH. 相似文献
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以不同浓度的硅酸钠、碳酸钠及二者混合物作稳定剂,研究它们对有效氯含量为0.5%(质量分数,下同)的次氯酸钠溶液化学稳定性的影响。测定稳定化处理后次氯酸钠溶液中有效氯的含量,结果表明:54 ℃下恒温密闭静置14 d后,加入硅酸钠、碳酸钠以及二者混合物作稳定剂的次氯酸钠溶液的有效氯,最高分别可保留初始浓度的88.16%、86.81%和92.85%;而不加任何稳定剂的次氯酸钠溶液在同样条件下其有效氯含量仅仅可保留初始浓度的76.58%。实验结果表明,硅酸钠和碳酸钠的混合物可以作为次氯酸钠溶液的良好稳定剂。 相似文献
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速溶硅酸钠属粉状无定形多硅酸钠,因易溶于水,故称速溶硅酸钠。将液体硅酸钠用烧碱调整模数后,经喷雾干燥瞬间脱水而制得。生产工艺简单,易实现自动化操作,产品指标要求高,生产中必须严格控制工艺条件。速溶硅酸钠主要作为建材助剂用于电力建设中,如:电厂烟囱、锅炉、烟道内衬砌筑用的耐酸耐热胶泥材料;还广泛用于大型设备的耐酸防腐中,如:化工、冶金行业耐酸槽内衬用的耐酸胶泥材料,还可添加在粉煤灰水泥材料中作为助磨剂和粉煤灰的活化剂。随着经济的发展,速溶硅酸钠需求量越来越大,已引起建材与化工界的重视。 相似文献
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以水玻璃(Na2O·SiO2)为硅源,以磷酸作为催化剂,经超临界二氧化碳干燥后得到了低密度(29.5 kg/m3)、
高比表面积(912 m2/g)、低导热系数[0.018 W/(m·K)]的二氧化硅气凝胶。通过测试水洗后溶液的电导率,系统分析了水的用量、水洗温度、水洗时间等因素对制备二氧化硅的水洗工艺除去钠离子的效率的影响。结果表明:使用5倍体积的水在40 ℃下水洗湿凝胶,经4次水洗之后能够去除91%以上的无机盐离子,缩短了水洗时间的同时避免了大量的水的使用。 相似文献
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U. Brenn H. Ernst D. Freude R. Herrmann R. Jhnig H. G. Karge J. Krger T. Knig B. Mdler U. -T. Pingel D. Prochnow W. Schwieger 《Microporous and mesoporous materials》2000,40(1-3):43-52
A sodium ilerite, molar ratios 1Na2O:8.2SiO2:10.2H2O, was obtained with a good crystalline structure and characterized by several NMR techniques in addition to X-ray diffraction (XRD). The X-ray pattern of the as-synthesized ilerite is in very good agreement with the structure proposed by Gies and coworkers. The narrow 29Si MAS NMR signals (FWHM=0.3 ppm) indicate a good short-range order of the framework. The proton dynamics influences several 29Si NMR parameters. The 16 ppm signal in the 1H MAS NMR spectra is explained by a proton in a bridging position in the short (2.3 Å) O4–O4 bonding. The quadrupole coupling constant Cqcc=100 kHz with η=0.2 for the 16 ppm signal, which was obtained from the 2H MAS NMR spectra, confirms this explanation. 17O NMR shows also a separate signal for SiOH groups but cannot resolve the three expected lines for SiOSi. PFG NMR detects a small mobile portion of water in the ilerite, which is located probably on the external surface of the crystallites. An intracrystalline diffusion coefficient of the intercalated water molecules of the order of magnitude 10−15 m2 s−1 was obtained by NMR tracer exchange experiments. 相似文献
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硅酸钠是一种重要的基础化工原料,由于近几年中国经济的快速发展,对硅酸钠产品提出更高的要求,因此出现了优质硅酸钠产品。重点介绍了优质硅酸钠的技术指标和有待深入探讨的问题,并联系实际介绍其加工工艺特点,同时对该产品的未来市场前景进行了探索。该产品的市场潜力很大,前景广阔,在近期内将强劲地发展。 相似文献
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中国泡花碱产业中氧气燃烧技术的应用与前景 总被引:1,自引:0,他引:1
泡花碱既是各种无机硅化物产品的原料,又是具有多种用途的终端产品。近几年国民经济各行业迅猛发展,对其需求量增加,出口量也在增大,刺激了泡花碱产业的发展膨胀。氧气燃烧技术是泡花碱产业新的突破点。氧气燃烧技术就是把“空气─燃料燃烧”过程变成“氧气─燃料燃烧”过程,称之为“氧气─燃料”燃烧,大大减少高温烟气量。目前“氧气燃烧”技术有3种基本方法:全氧燃烧、纯氧助燃和富氧燃烧。 相似文献
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介绍了喷雾干燥设备在速溶硅酸钠生产工艺中的应用情况 ,对干燥过程中出现的问题提出了解决的方案 ,通过对常规干燥设备进行调整和改造后得到了合格的产品 相似文献
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聚硅酸硫酸铝的生产技术与研究进展 总被引:1,自引:0,他引:1
聚硅酸硫酸铝是一种高效的复合型絮凝剂,具有广阔的应用前景。概述总结了聚硅酸硫酸铝的结构研究进展以及国内外的生产技术,并根据作者的实际研究经验对保证产品稳定性的关键技术进行了简要的评述,认为产品稳定性及混凝效果是影响其工业化的一个重要因素,如何提高产品稳定性是今后研究的一个重要方向。 相似文献
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简要介绍了目前国内硅酸钠的主要生产方法,综述了我国硅酸钠应用领域的开发现状。提出了几点建议:国内硅酸钠的生产应集中化,以降低消耗;液体和粉状产品可并举生产;开拓新应用领域。 相似文献
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By using industrial sodium silicate solution as raw material,high purity SiO2 powder was successfully synthesized by the split-step carbonation method.The relations between pH value of end point and the removal percentage of impurity at the first carbonation and the purity and yield of product SiO2 powder at the second carbonation were studied.The SiO2 powder was characterized by using XRD,SEM,IR and composition analysis.The results showed that when the pH value of end point at the first carbonation was 10.9,the purity of SiO2 prepared was up to 99.9%.The SiO2 powder synthesized was amorphous with regular sphere shape,uniform size and no reunion.The reaction mechanism was also discussed. 相似文献
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The trimethylsilylation of sodium silicate in solution was carried out using magnetic and ultrasonic mixing. The maximum yield of trimethylsilylated product was obtained by magnetic stirring. The product having the higher molecular weight was formed using ultrasonic as well as magnetic mixing. The product was a white amorphous solid, soluble in most organic solvents. 相似文献
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添加石灰作为脱硅剂,对含硅酸钠的碱浸脱硅液进行脱硅处理后回收。将脱硅后的碱液对高硅铝土矿进行循环脱硅,考察钙硅物质的量比、苛碱浓度、初始硅浓度及脱硅时间对脱硅率的影响,并在较佳溶液脱硅条件下验证循环脱硅效果。脱硅结果表明,在碱性条件下[ρ(Na2O)≈100 g/L],将石灰按钙硅物质的量比为1.2进行添加,反应2 h后溶液中二氧化硅质量浓度从约为7 g/L降至约为1 g/L。循环脱硅的结果表明,碱液经5次循环后,铝土矿中的n(Al)/n(Si)均大于7。这不仅为氧化铝工业生产提供了理论指导,也为碱液循环利用提供了一种有效途径。 相似文献