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脱硫石膏经过热处理批量制备建筑石膏,不仅可以缓解环境污染问题,还具有一定的经济效益。以电厂脱硫石膏为原料,添加氧化锌为转晶助剂,通过热处理调控脱硫石膏煅烧产物的晶体结构,从而制备高性能的建筑石膏,并研究了氧化锌添加量和煅烧温度对建筑石膏性能的影响。结果显示,氧化锌助剂的添加拓宽了脱硫石膏煅烧成半水石膏的温度范围,还改善了煅烧产物的结晶度。脱硫石膏中添加0.6%氧化锌(以质量分数计),在180 ℃煅烧制备的建筑石膏性能最佳。水化2 h产物的形貌为相互交叉堆积的针状或纤维状晶体,2 h抗折和抗压强度分别达到3.8 MPa和9.2 MPa,符合3.0等级建筑石膏标准的要求,可以实现脱硫石膏的规模化资源利用制备高性能的建筑石膏。 相似文献
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脱硫石膏是火力发电厂烟气脱硫时由SO2和CaCO3反应生成的一种工业副产石膏,主要成分为CaSO4·2H2O3还含有一些杂质。 相似文献
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应用电厂脱硫石膏生产石膏砌块及发展前景 总被引:6,自引:0,他引:6
电厂烟气脱硫石膏是我国工业副产石膏的最大资源,采用先进的工艺对脱硫石膏进行烘干煅烧,且应用于石膏砌块生产,开发新型墙体材料,开拓建筑市场,是脱硫石膏资源利用的新途径,发展前景广阔. 相似文献
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通过对湿法烟气脱硫石膏性质的分析,利用建筑石膏三相分析原理,从脱硫石膏原料纯度、残余二水石膏含量、粉磨工艺、煅烧设备等方面,对利用烟气脱硫石膏煅烧制备建筑石膏的影响因素进行了研究探讨。 相似文献
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利用脱硫石膏作为基本材料,通过不同的煅烧条件得到性能不同的脱硫建筑石膏.通过分析认为,脱硫石膏实验室的最佳煅烧条件为155℃、2 h,得到的脱硫建筑石膏属于优等高强建筑石膏.由上述脱硫建筑石膏配制一种胶凝材料,各项性能指标优良. 相似文献
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脱硫石膏作水泥缓凝剂研究 总被引:17,自引:3,他引:17
研究了利用脱硫石膏作水泥缓凝剂的水泥性能以及脱硫石膏的作用机理。研究表明,脱硫石膏中含有一定量的碳酸钙,掺入脱硫石膏,水泥凝结时间正常,对水泥力学性能和安定性有积极作用,可以代替天然石膏用于水泥生产。此外还研究了脱硫石膏的造粒以及使用脱硫石膏给生产企业带来的显著经济效益。 相似文献
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脱硫石膏综合利用现状 总被引:2,自引:0,他引:2
随着全球对环境保护日益增长的重视,电站锅炉尾部烟气的二氧化硫排放量控制成为大气污染物治理的重中之重。石灰石—石膏湿法脱硫工艺是世界上应用最广泛的一种脱硫技术。文章分析烟气脱硫石膏性能,探讨脱硫石膏的综合利用前景,总结了脱硫石膏在综合利用的过程中应考虑的问题。 相似文献
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George A. King Mayhew J. Ridge Graham S. Walker 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1973,23(8):635-638
Chloride in a number of samples of gypsum and calcined gypsum has been determined by Surkevicius's method and by nephelometry. Results from the former method are confirmed. Sodium was determined by atomic absorption spectroscopy and the content found to be considerably greater than the equivalent of the chloride. Two of the samples appeared to contain close to 0.1% of Na2SO4 and it is suggested that standards for the quality of gypsum should specify the determination of sodium as well as that of chloride. 相似文献
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《Journal of the European Ceramic Society》2006,26(4-5):777-783
This paper reports the synthesis of large plate-like gypsum (calcium sulfate) dihydrate generated from waste gypsum board via a wet process. Gypsum hemihydrate was formed by dehydrating waste gypsum board in a sodium sulfate solution at 100 °C for 1 h to form needle-like crystals. The large gypsum dihydrate was formed by lowering the temperature of the gypsum hemihydrate suspension below 80 °C. The large plate-like gypsum dihydrate was obtained by adding seed crystals to a suspension cooled at 80 °C. When 40 μm seed crystals were added at 0.5 mass%, the large plate-like gypsum dihydrate crystals obtained from waste gypsum board had average dimensions of 250 μm length × 100 μm width × 35 μm thickness. 相似文献
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<正>我公司是年生产能力20万t的水泥粉磨站,有2条由MB2275管磨机和NHX600高效转子式选粉机组成的闭路水泥生产线。2008年3月份开始,我公司 相似文献
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脱硫石膏是电厂湿法烟气脱硫的固体废弃物,不仅造成资源浪费,还会对环境产生污染。为提高脱硫石膏的附加值,以脱硫石膏为原料,采用盐溶液法制备半水石膏晶须,研究了氯化钠浓度、温度、液固比、pH对转化率的影响,并研究了柠檬酸的含量对形貌的影响。采用傅立叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)等对制备的半水石膏晶须做了表征,并研究了柠檬酸对形貌影响的机理。研究表明:当氯化钠质量分数为20%、反应温度为100 ℃、液固比为5∶1、反应时间为2 h、柠檬酸的质量分数为0.25% 时,可制备出长度为50~100 μm、长径比为(30~50)∶1的半水石膏晶须。 相似文献
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脱硫石膏作为电厂最大的固体废弃物之一,对其进行研究将其回收利用具有重要的意义。以电厂干法脱硫石膏为原料,采用将亚硫酸钙氧化并重结晶的方法制备二水石膏(CaSO4·2H2O),以用于水泥缓凝剂。考察了溶液pH、液固比(质量比)、催化剂用量、空气流速、反应时间等因素对亚硫酸钙氧化转化率的影响。得到亚硫酸钙氧化为二水石膏的最佳工艺条件:溶液pH为4~5、反应时间为1.5 h、催化剂用量(亚硫酸钙与催化剂的质量比)为7.5、空气流速为0.15 m3/h、液固比为10∶1。在此条件下,亚硫酸钙转化率接近100%。实验得到的二水石膏产品晶形良好、便于过滤,为后续工业化放大奠定了基础。 相似文献
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S Agatzini‐Leonardou T Karidakis PE Tsakiridis 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(3):320-324
The possibility of replacing the natural gypsum used in cement production by a chemical precipitate consisting of gypsum (CaSO4 ·2H2O) and brucite (Mg(OH)2), was investigated. This precipitate is a by‐product of a new hydrometallurgical process, which was developed in order to treat economically low‐grade nickel oxide ores. More specifically, it is obtained by hydrolytic precipitation of magnesium at temperatures not exceeding 80 °C, from sulfate solutions which result from heap leaching of nickel oxide ores with dilute sulfuric acid at ambient temperature, using calcium hydroxide as a neutralizing agent. The mixture generally consists of 20–30% non‐fibrous magnesium hydroxide, 60–75% gypsum and any excess of calcium hydroxide, depending on the precipitation conditions. In the present work, a mixture was produced by hydrolytic precipitation at 25 °C, using 1.1 times the stoichiometric quantity of Ca(OH)2 required to precipitate all of the magnesium. The possibility of using the above precipitate as a substitute for gypsum in cement was examined by testing four different cement mixtures, one reference sample, containing 4.5% gypsum and 0.5% anhydrite ((PC)Ref) and another three with 4.1%, 5.2% and 6.3% of gypsum/brucite mixed precipitate ((PC)B/G), in the place of gypsum. All samples were tested by determining the grindability, setting time, expansion and compressive strength. The results of the physico‐mechanical tests showed that the replacement of natural gypsum by the above precipitate did not affect negatively the quality of the produced cements. Copyright © 2005 Society of Chemical Industry 相似文献
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Julius Beretka Douglas N. Crook George A. King 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1981,31(1):151-162
Four samples of by-product gypsum were analysed by chemical and physical methods and subjected to comparable degrees of calcination in a special rotary furnace. The hydration characteristics of the resulting calcium sulphate hemihydrates were determined in terms of three basic parameters viz. α0, a measure of heterogeneous nucleation in the system; k, a measure of self-acceleration of the reaction; and θ, the period of induction. Measurements were made of the size distribution of particles, pH, water requirement, the colour and compressive strength of cast gypsums made from the hemihydrates, and comparisons were made with two samples of calcined natural gypsum. Additions of calcium oxide were also made to the by-product gypsums and the same procedures followed. Hydration of the calcined products resulted in considerable differences in the kinetic parameters. Both differences in nucleation and transport of calcium sulphate from the grains of hemihydrate to the growing crystals of the dihydrate seemed to contribute to variations in reactivity. The by-product gypsums calcined alone, or in the presence of calcium oxide, yielded hemihydrates with water requirements greater than those of the calcined natural gypsums. The compressive strengths of cast gypsums made from these hemihydrates were somewhat less than those made from the calcined natural gypsums. The colour co-ordinates were about the same. After treatment with calcium oxide, the by-product gypsum appears to be suitable for making plaster of Paris. 相似文献