共查询到19条相似文献,搜索用时 125 毫秒
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在硅酸盐水泥熟料中进行了天然石膏和改性磷石膏不同比例单掺、双掺作水泥缓凝剂的一些系列对比试验,通过对凝结时间、安定性、强度等常规物理性能测试以及XRD、SEM等微观结构分析,研究改性磷石膏对水泥缓凝剂方面的影响。研究表明,改性磷石膏与天然石膏单掺、双掺作水泥缓凝剂均具有良好的缓凝、提高强度作用。 相似文献
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改性磷石膏用作水泥缓凝剂 总被引:5,自引:1,他引:5
选用磷渣配料生产的熟料,进行了改性磷石膏作水泥缓凝剂的试验,采用自制改性剂,并经过热处理,对磷石膏进行改性,对比了改性磷石膏和天然石膏作缓凝剂的使用效果,结果表明,与天然石膏要比自制改性剂并经煅烧工艺制得的改性磷石膏作缓凝剂,水泥凝结时间一致或稍有缩短,早期强度略低,强度增进率较高,水泥安定性合格,并提出了水泥中SO3含量的控制范围。 相似文献
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用两种无机非金属材料对磷石膏进行改质,使磷石膏中P2O5、F^-、SO4^2-生成难溶于水的钙盐。试验对改质前后确石膏及天然二水石膏作缓凝剂时水泥性能进行了对比,结果表明,改质后磷石膏作缓凝剂的水泥凝时间及1d、3d、28d强度接近或好于掺天然二水石膏的水泥。 相似文献
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磷石膏直接应用于水泥生产作缓凝剂的研究 总被引:3,自引:0,他引:3
磷石膏直接应用于水泥生产作缓凝剂的研究张洪江苏省徐州市中国矿业大学综合系(221008)马进江苏省徐州市第二水泥厂朱海宏,靳天祥徐州市磷肥厂磷石膏是生产磷酸时排出的工业废渣,其主要成分与天然石膏相同,如能直接代替天然石膏作水泥缓凝剂,则具有良好的社会... 相似文献
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磷石膏作缓凝剂在水泥生产中的应用 总被引:2,自引:1,他引:2
磷石膏作缓凝剂在水泥生产中的应用孙国芳江苏省扬中县水泥厂(212200)1磷石膏的物化特性及作缓凝剂的可行性水泥工业生产中一般以天然石膏作通用水泥的缓凝剂,而化学副产石膏的应用并不普及,磷石膏是湿法制造磷酸的工业废渣,含自由水20%~30%,外观为灰... 相似文献
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研究了工业化生产的改性磷石膏球对水泥标准稠度用水量、凝结时间、胶砂流动度、胶砂强度及水泥与减水剂相容性的影响,并与原状磷石膏和天然石膏进行对比,结合X-射线衍射、综合热分析等微观测试,分析了改性磷石膏球对水泥水化产物相、水化程度的影响.结果表明:采用改性磷石膏球配制的水泥,其初凝、终凝时间与掺配原状磷石膏水泥相比分别缩短217 min、227 min,1d、3d强度显著高于原状磷石膏配制的水泥,28d强度高于天然石膏配制的水泥,且标准稠度用水量、胶砂流动度、与减水剂的相容性等指标优于天然石膏配制的水泥.改性磷石膏球对水泥早期水化无不良延缓作用,且能提高水泥后期水化程度.综合对比上述三种石膏对水泥性能影响的各项指标,认为改性磷石膏球可以完全替代天然石膏作水泥缓凝剂. 相似文献
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本文研究了脱硫石膏代替天然石膏作水泥缓凝剂时对水泥性能的影响,并在实际生产中进行了工业试验。研究表明,脱硫石膏代替天然石膏作水泥缓凝剂,水泥各项指标符合要求,可以代替天然石膏用于水泥生产。此外针对脱硫石膏粘性强极易粘附在设备上,造成积料、堵塞等情况,对脱硫石膏的输送和喂料问题提出了解决方案。 相似文献
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赤泥改性磷石膏作水泥缓凝剂 总被引:1,自引:0,他引:1
在对磷石膏直接应用于水泥中的危害分析的基础上,用赤泥对磷石膏在焙烧条件下进行改性。结果表明:磷石膏与赤泥按1∶5混合后,在800℃进行焙烧,保温2h后急冷,可消除磷石膏中有害杂质对水泥的不良影响,能代替天然石膏作水泥的缓凝剂,并且对水泥的强度具有增强效果。 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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一种增强型水泥促凝剂的研究 总被引:1,自引:0,他引:1
研究了由特定条件下煅烧的石膏和芒硝组成的促凝剂对水泥强度、凝结时间及其它性能的影响。研究结果表明,该促凝剂对掺有矿渣、沸石和炉渣混合材料的水泥有明显的促凝和增强作用,当煅烧石膏和芒硝在水泥中的掺量分别为4%和2%时,水泥3d和28d抗压强度分别增加5.5MPa~11MPa和3MPa~6MPa,水泥凝结时间明显缩短,初凝时间缩短约30min~50min.终凝时间缩短约25min~120min 相似文献
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The present work describes a study of setting and hardening of blends of borogypsum, fly ash, and Portland cement clinker (PC). The possibility of using borogypsum instead of natural gypsum in fly ash-cement matrix has been investigated through several tests. In addition, the effects of molasses on the setting times of cement and strength of the mortar were also studied. The setting times of the cement were retarded when the natural gypsum was replaced by borogypsum. Molasses exhibited a rather significant retarding effect when used in combination with borogypsum in cement. The inclusion of molasses to the system at a level of 0.1% resulted in a reduction in early strength of the mortar. However, it significantly enhanced the strength of the mortar after 7 days of curing age. In general, the cement prepared with borogypsum was found to have similar strength properties to those obtained with natural gypsum, and inclusion of molasses into the system significantly increased the strength of the sample after 7 days of curing age. 相似文献
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Calcium lignosulphonate (CL)-sodium bicarbonate (SB) (a total of 0.7% by weight of cement and CL to SB ratio of 1:1.8) will cause the fluidity of fly ash cement paste to decrease rapidly. It is the variation of the status of ettringite crystallization that causes this phenomenon. Experimental results show that CL-SB affects the liquid-phase composition of fly ash cement paste remarkably. As a result, ettringite crystallizes out in the shape of needles from the solution. These needle-like crystal particles are distributed in the solution at a certain distance from the surface of clinker particles. At the initial hydration stage, the crystallization of ettringite is stronger in fly ash cement with calcined gypsum than in fly ash cement with gypsum. 相似文献
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Recep Boncukcuo?lu M.Tolga Y?lmazM.Muhtar Kocakerim Vahdettin Tosuno?lu 《Cement and Concrete Research》2002,32(3):471-475
Boron ores are used in the production of various boron compounds such as boric acid, borax and boron oxide. Boric acid is produced by reacting colemanite(2CaO·3B2O3·5H2O) with sulphuric acid and a large quantity of borogypsum is formed during this production. This waste causes various environmental problems when discharged directly to the environment. Portland cement is the most important material in the building industry. This material is produced by adding about 3-5% gypsum (CaSO4·2H2O) to clinker as a set retarder. The aim of this study was to stabilize borogypsum, and to produce cements by adding borogypsum instead of natural gypsum to clinker. Concrete using cement produced with borogypsum was tested to find the mechanical properties and the test values were compared with those of concrete from cement with natural gypsum. Compressive strength of concrete from cement produced with borogypsum was found to be higher than that of natural gypsum. Also, the setting time of cement with borogypsum was longer than that of the Portland cement. 相似文献
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掺煅烧石膏水泥早期水化过程的研究 总被引:8,自引:2,他引:8
利用DTA,XRD,IR测定水泥水化浆体的化学结合水和Ca(OH)2的生成量,研究了煅烧石膏,二水石膏对硅酸盐水泥早期水化过程的影响。结果表明:在水化龄期相同时,掺煅烧石膏水泥浆体中水化产物同掺二水石膏相比,Ca(OH)2生成量大;在1d前无钙钒石(AFt)生成,结合水量在1d前,前者高于后者,而1d后则相反。指出了煅烧石膏加快水泥水化产物形成的机理在于:由于它的溶解度较低,在水泥水化初期(1d前),存在于水泥中的铝酸盐相不能形成AFt,从而减缓了AFt对水泥水化的延缓作用,加速了整个熟料矿物相的水化。 相似文献