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1、摘要本课题对天然硬石膏的组成、结构和水化硬化性能进行分析,研究天然硬石膏的活性及不同激发途径,着重研究了粉磨活化、煅烧活化及复盐激发剂这三种途径对硬石膏进行活性激发,通过测定硬石膏的水化率、标准稠度、凝结时间和硬化体强度等对不同激发途径下水化硬化特性进行了研究。采用SEM和XRD等测试技术,研究了硬石膏硬化体中二水石膏的晶体形貌以及煅烧后硬石膏的晶体结构。试验研究结果表明,粉磨是提高硬石膏水化活性的有效手段,粉磨使天然硬石膏的致密结构遭到破坏,颗粒细化,与水接触的比表面积增加,水化作用增强。粉磨时间越长,能耗消耗随之也增大,因此粉磨时间不宜过长,硬石膏细度控制在4000~5000
2、cm2/g为宜。在一定的热处理下,硬石膏的水化能力也有所增强。硬石膏煅烧后,其晶格发生畸变,提高了表面自由能,同时也提高了易磨性,试验表明,150℃下煅烧效果最好。经150℃煅烧,硬石膏中的CaSO4·2H2O分解生成β-CaSO4·1/2H2O,β-CaSO4·1/2H2O具有很高的水化活性,它能够快速水化生成的CaSO4·2H2O,对硬石膏的水化产生晶种诱导效应,使硬石膏在液相中CaSO4·2H2O晶体成核与生长速率加快。单掺5%煅烧明矾后,3d水化率为60.37%,28d水化率达74.32%;通过粉磨、煅烧和掺加5%煅烧明矾复合,3d水化率64.02%,28d达到78.26
3、%,比未经任何处理的天然硬石膏(3d水化率12.75%,28d水化率29.73%)早期水化率有了显著的提高。关键词天然硬石膏;粉磨;煅烧;激发剂;活性AbstractThesubjectofnaturalanhydriteincomposition,structureandhydrationandhardeningperformanceanalysisoftheactivityofnaturalanhydriteanddifferentexcitationchannels,focusesonthegrindingactivated,calcineddoublesaltactiva
4、toractivationandthreewaysofanhydriteTostimulateactivity,bymeasuringthehydrationrateofanhydrite,standardconsistency,settingtimeandstrengthofhardenedwaterofdifferentwaystostimulatethehardeningcharacteristicswerestudied.TestingusingSEMandXRD,technology,researchtheanhydritegypsumhardenedbodyofthe
5、crystalmorphologyandcrystalstructureofcalcinedanhydrite.Experimentalresultsshowthattheactivityofgrindingistoimprovethehydrationofanhydriteeffectivemeansofgrindingtomakethestructureofnaturalanhydriteinthedestructionofdense,particlerefinement,withtheincreaseofwatercontactsurfacearea,hydrationin
6、creased.Thelongerthegrindingtime,energyconsumptionhasincreasedalongwith,sothegrindingtimenottoolong.Anhydritefinenesscontrolinthe4000~5000cm2/gisappropriate.Undercertainheattreatment,thehydrationcapacityofanhydritehasalsobeenenhanced.Anhydriteaftercalcination,thelatticedistortionandimprovethe
7、surfacefreeenergy,butalsoimprovesthegrindabilitytestshowsthat,150℃calcinedbest.Calcinedat150℃,anhydriteCaSO4•2H2Ointhedecomposedβ-CaSO4•1/2H2O,β-CaSO4•1/2H2Ohighhydrationactivity,itcangeneraterapidhydrationofCaSO4•2H2O,thehardGypsumseedproduc