共查询到20条相似文献,搜索用时 203 毫秒
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本文采用离子交换树脂法和正交试验法,对山西临汾地区风化煤中黄腐酸的提取进行了研究。发现离子交换反应的速度与反应原料的颗粒大小,反应原料和树脂的比例,反应原料和水的比例,反应的时间和温度有关。通过正交试验法对离子交换反应的提取条件进行优化,选择出了提取黄腐酸的最佳条件:风化煤80目,原料和树脂比例1:2.5,原料和水的比例1:20,反应温度65℃,反应时间120分钟。进一步研究对提取黄腐酸具有一定的实用价值。 相似文献
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超细氧化镁催化合成乙酰丙酮的研究 总被引:6,自引:0,他引:6
采用超细氧化镁作催化剂,乙酰乙酸乙酯和乙酸酐为原料,对乙酰丙酮的合成进行了研究,确定了最佳工艺条件;反应时间18h,温度130℃,原料摩尔比n(乙酰乙酸乙酯)/n(乙酸酐)=1.0,催化剂用量(MgO)=0.75%,乙酰丙酮的收率95%左右。 相似文献
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由乙酰乙酸乙酯和乙二醇为主要原料,采用有机酸为催化剂,合成了苹果酯。研究了催化剂用量、原料配比和反应时间对反应收率的影响。确定了反应条件:原料配比为1:1.3,催化剂用量为0.65g,反应时间5h,产物收率可达88.5%,纯度98.5%。 相似文献
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利用双塔精馏两条工艺路线对原料粗酚进行分离,提纯苯酚,三混甲酚等产品.研究了理论塔板数的简捷计算和塔板数的测定,以及回流比对产品质量的影响,并对产物进行物料衡算 相似文献
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用同离子效应以Mgcl2对恒沸盐酸中HCl的富集进行研究.使工业盐酸生产试剂盐酸的收率从67.99%提高到99.74%,原料成本降低约31%. 相似文献
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2-噁唑烷酮合成的工艺研究 总被引:1,自引:0,他引:1
本文研究了2-唑烷酮的合成,产品收率为58.2%,纯度为86.4%。对原料配比、溶剂用量、反应温度及反应时间等影响因素进行了探讨,确定了较佳的反应条件。 相似文献
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本文研究了2-恶唑烷酮的合成,产品收率为58.2%,纯度为86.4%,对原料配比,溶剂用量、反应温度及反应时间等影响因素进行了探讨,确定了较佳的反应条件。 相似文献
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Jose Luis Amorós Arnaldo Moreno Encarna Blasco Joaquin Javier Pérez Sandra Navarro Sandra Reverter 《International Journal of Applied Ceramic Technology》2019,16(6):2153-2160
Inkjet technology has become very popular in recent years and is nowadays widely used for decorating ceramic products. This has led to in-depth study of the operating principles and process variables involved. These notably influence the properties of the deposited ink layers, as do the physicochemical properties of the applied inks and of the glazes on which the inks are deposited. The problems associated with these factors are further heightened when inks with complex formulations designed to obtain special effects and specific surface properties are used. This study examines the characteristics of the interface that developed on applying an ink on a certain type of glaze, as well as the surface properties of the final product. The relationship of the amount of ink applied per unit area and the particle size distribution (PSD) of the glaze on which it was deposited to ink penetration into the glaze layer was also investigated. The resulting microstructures were observed by SEM, while the variation of glaze layer composition with distance to the surface was determined by SEM-EDS. The results obtained were successfully correlated with the porous texture of the unfired glaze (determined by SEM and mercury porosimetry) and with unfired glaze PSD. 相似文献
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以粉煤灰为基体材料,铝粉为相变介质,采用混合烧结法制备直径为15 mm的球形高温复合定形相变材料,利用浸釉法,采用四种烧结制度制备低温黑釉表面涂层,通过渗水率及微观表征评价其防水性能。研究表明,釉层烧结温度及釉浆浓度对釉层性能有显著影响。在釉层烧结温度为950 ℃的条件下,釉浆体积浓度高于90%时,由于坯釉之间膨胀系数差异过大,以及有机分解产物在釉粉末熔融前尚未完全释放而导致釉层龟裂和焦化;当体积浓度大于80%而小于90%时,釉层表面致密度增加,防水性能增强,但存在流釉现象。烧结温度为870 ℃及810 ℃,釉浆体积浓度为85%~95%时,釉面光泽度好且流釉减少,防水性能增强。烧结温度为750 ℃时,因温度过低使釉层间气体无法及时排出导致釉面针孔增多,防水性能下降。对比四种烧结制度下釉层性能,当釉层的最高烧结温度为810 ℃,浆料体积浓度为88%~92%时,涂层致密度高,与球形相变材料表面之间密着性好,防水性能突出,实验重复性良好。 相似文献
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Earl S. McCutchen 《Journal of the American Ceramic Society》1944,27(8):233-238
Strontia has proved to be a strong flux and a desirable glaze ingredient when it is used to replace PbO, ZnO, and CaO in a typical dinnerware glaze. By including it in the frit, the fluidity of the glaze was increased to a marked degree when it was substituted for ZnO and CaO and it also lowered the deformation temperature in the replacement of the latter oxide. Thermal-expansion tests indicate that strontia has practically the same effect as lime on glaze expansion. Glazes of excellent visual and physical properties were obtained in a series of low-lead and leadless compositions containing strontia. 相似文献
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由于钛釉价格低,制成的乳浊釉遮盖能力极强,已经受到了人们的高度重视。本文主要介绍了钛釉的主要性质及其乳浊机理,以便人们对其进行更深一步的研究。 相似文献
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钛釉的性质及乳浊机理 总被引:1,自引:0,他引:1
由于钛釉价格低,制成的乳浊釉遮盖能力极强,已经受到了人们的高度重视。主要介绍了钛釉的主要性质及其乳浊机理,以便人们对其进行更进一步的研究。 相似文献
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The structure of aluminoborosilicate glasses is considered. It is found that the coordination states of boron and aluminum in glasses may vary depending on the composition, which has a perceptible effect on the properties of glaze glasses. Significant discrepancies were found between the experimental and calculated TCLE values of such glasses, which is due to a changed content of four-coordination boron and the emergence of six-coordination aluminum. Considering these data, it is possible to predict the physicochemical properties of glaze glasses. 相似文献
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搪玻璃是一种在金属表面喷涂瓷釉(搪玻璃釉),经高温搪烧密着而成的复合材料,既具有玻璃的化学稳定性,又具有金属材料的硬度大、强度高等优良特性,同时表面光滑易清洗,因此在化工、医药等行业广泛应用。搪玻璃性能取决于搪玻璃釉的成分,搪玻璃釉包括基体剂、乳浊剂、助熔剂、密着剂等,其中助熔剂中含有低熔点物质,能够降低熔化温度,破坏搪玻璃釉连续的网络结构,形成新分子键,进而改良搪烧工艺;密着剂能够与金属基体发生化学反应,增强搪玻璃釉和金属基体的结合强度,进而提高力学性能。本文简要介绍了搪玻璃釉中的各类助剂,着重叙述了助熔剂和密着剂的组成及作用机理,为今后设计搪玻璃釉及提高搪玻璃设备性能提供了参考依据。 相似文献