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介绍了我国脱硫石膏综合利用的现状。在此基础上,总结了以脱硫石膏为原料制备α型半水石膏(高强石膏)的主要制备方法以及当前国内外学者研究的进展和成果。最后比较了蒸压法和水热法制备高强石膏的优缺点。 相似文献
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以磷石膏为原料,采用常压盐溶液法在硝酸镁溶液中制备α-半水石膏,以凹凸棒土和聚氨酯为载体、十水硫酸钠和结晶乙酸钠二元共晶水合盐为相变材料,采用真空吸附法制备定形相变材料,然后将α-半水石膏与定形相变材料复合制备磷石膏基相变材料,并考察了其机械强度和储放热性能。结果表明,由磷石膏制备的α-半水石膏抗折、抗压强度分别为8.9、36.8 MPa,定形相变材料的相变温度为28.5 ℃,相变焓为82.6 J/g。由于掺入相变材料导致石膏晶体结合点减少,磷石膏基相变材料抗压强度降低,但其仍然能够达到建筑石膏的使用要求。升、降温实验结果表明,磷石膏复合相变材料与纯磷石膏保温箱相比,温差为8.9 ℃,具有一定的储能效果。 相似文献
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采用加压水溶液法以脱硫石膏为原料制备高强石膏,其工艺参数是决定高强石膏制备品质的关键。通过研究水热温度、水热时间、搅拌转速及料浆浓度四种工艺参数对α型高强石膏性能的影响规律,对不同工艺参数下制备样品的晶体形貌和石膏相组成进行定性及定量分析,并优化出加压水溶液法制备α型高强石膏的最佳工艺。结果表明,水热温度对生成晶体的尺寸及长径比的影响较大,水热时间主要影响晶体的尺寸,对长径比的影响不大,而水热温度和水热时间是影响α型高强石膏相组成的重要因素。搅拌转速和料浆浓度主要影响高强石膏尺寸及长径比,对石膏相组成影响不大。在最佳工艺条件下:水热温度130 ℃、水热时间4 h、搅拌转速250 r/min及料浆浓度30%(质量分数),制备的α型高强石膏2 h抗折强度为5.4 MPa,烘干抗压强度为41.9 MPa。 相似文献
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The effects of: iron sulphate in an acid urea medium, potassium sulphate, three mixtures of potassium sulphate with iron sulphate, a mixture of potassium chloride with iron sulphate, ammonium sulphate with nitrification inhibitor (DCD) plus iron sulphate and, finally, sequestrene, in correcting iron chlorosis in peanuts (Arachis hypogea) on a soil containing 65% CaCO3, pH 7.6, known to induce chlorosis, were tested in pot experiments. The potassium sulphate-iron sulphate mixtures were as effective as sequestrene or more so in correcting chlorosis. The potassium chloride mixture and the ammonium sulphate-DCD-iron sulphate mixture were less effective, the latter probably because of ammoium toxicity. Iron sulphate or potassium sulphate alone had no effect. The effective correction of iron chlorosis requires simultaneous application of iron and potassium sulphates. 相似文献
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以尼龙6为基体树脂,硫酸钙晶须和短玻纤为增强材料制备了硫酸钙晶须/短玻纤/尼龙6复合材料,研究了不同晶须含量对复合材料力学性能的影响。结果显示,晶须含量不超过10%时,晶须与短玻纤对尼龙6有协同增强作用,拉伸强度、弯曲强度和弯曲模量分别提高了8.7%、7.5%和8%;经过表面处理的晶须增强效果好于未经表面处理晶须;采用侧向加入增强材料方式制备的复合材料力学性能远优于主料口加入方式。 相似文献
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Binders are generally inorganic, organic or organomineral and have an important influence on the performance and corrosion resistance of slag line and deskulling. Since silicate and phosphate binders have some side effects, in this work sulphate binders such as sulphamic acid, H2NSO3H; aluminum sulphate, Al2(SO4)3; ammonium sulphate, (NH4)2SO4; magnesium sulphate, MgSO4; calcium sulphate, CaSO4; sodium sulphate, Na2SO4; and potassium sulphate, K2SO4, are investigated. Cold crushing strength at different heat treatments of room temperature, 110 °C, 1100 °C, 1400 °C is measured. Apparent porosity of samples without pulp and bulk density together with pH of the binder solution is evaluated and XRD and SEM studies are performed. Among these sulphate binders MgSO4 was found to be the best. It is acidic in nature and develops strong bonds to the basic aggregate, MgO, at low temperatures. At high temperatures it dissociates from MgO(s) and SO3(g) and the remained portion of MgO is the same as host oxide, with no corrosion and easy deskulling. Basic binders such as calcium sulphate, sodium sulphate and potassium sulphate could not strongly bond the MgO aggregates. 相似文献
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对粗硫酸盐松节油的净化方法加以探讨 ,总结出较为理想的化学 -物理净化法。经试验 ,该法能较好地去除粗硫酸盐松节油中臭味及深色物质 ,得到优质精制硫酸盐松节油产品 ,具有良好的实用价值。 相似文献
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E. J. Nyns M. Lambert A. L. Wiaux 《European Journal of Lipid Science and Technology》1969,71(3):232-236
Twenty strains of bacteria isolated in a medium with lauryl sulphate as carbon source and twenty strains isolated with tridecyl benzenesulphonates were compared, with respect to growth and ability to degrade detergents, in submerged cultures containing one of these surfactants as major source of carbon. No strain was ideally suited for detergent biodegradation. Most bacteria isolated on lauryl sulphate rapidly degraded lauryl sulphate completely whereas they degraded tridecyl benzenesulphonates to a lesser extent than bacteria isolated on tridecyl benzenesulphonates. The latter strains, in turn, degraded lauryl sulphate at a lower rate and incompletely. 相似文献
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一水硫酸镁是较七水硫酸镁含硫镁成分高、附加值大、市场前景广阔的重要化工原料及双元素肥料。苦土法生产的一水硫酸镁品质较低,不能满足市场要求。通过比较高温结晶法和干燥脱水法的工艺特点,以及所涉及的多种设备,在掌握相关资料及小试实验数据的基础上,采用盘式干燥机直接干燥七水硫酸镁的方式制取一水硫酸镁。实验结果表明,该种盘式干燥机在温度为160 ℃、搅拌转速为15 r/min情况下的干燥强度(以水计)为4.1 kg/(m2•h)。使用盘式干燥机可以较好地生产出满足品质要求的一水硫酸镁,使用该机单位产品能耗适中,单位产品净收益在合理范围内。 相似文献
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Y. Xu 《Cement and Concrete Research》1997,27(12):1841-1850
Ordinary Portland cement (OPC) and OPC/ground granulated blastfurnace slag (GGBS) 65% cements containing 2.0 to 9.0% sulphates derived from sodium sulphate and calcium sulphate were investigated in respect to their chloride binding properties and the concentrations of chloride and hydroxyl ions in the pore solutions. Chlorides derived from sodium and calcium chlorides were introduced at the time of mixing. The results indicate that calcium sulphate has a different effect on chloride binding and the pore solution chemistry than sodium sulphate. The slag cement has higher chloride binding capacities as a result of simple replacement for OPC, but at the same sulphate contents, the slag cement does not give the expected higher binding capacities, suggesting that the difference in sulphate content between the two cements may be the main reason for their different chloride binding behaviour. 相似文献