Quantitative XRD Analysis of Cement Clinker by the Multiphase Rietveld Method

1　IntroductionPhasesincementclinkerhavebeenquantifiedbyBouge ,microscopeorXRDmethods .TheBougemethodisareconstructionofthechemicalanalysis ,basedonanequilibriumsystem ,whilemicroscopecountingistediousandtime -consuming .Aldridgegaveasummaryofthestatusoftheaccuracyandprecisionofphasequantifica tioninPortlandcementbytheabovethreebasictech niques .HepointedouttheXRDmethodhasagreaterpo tentialforanindustriallaboratorythantheBougeormi croscopemethods[1] .However,theXRDmethoddidnotgivesatisfa…     

Influence of characteristics of alumina-silicate raw materials on the formation process of clinker

The traditional alumina-silicate raw materials, for example, clays, in the precalcining technique of cement production, have been replaced by low grade and high silica content sandstones, shales, and industrial waste residues, including fly ashes, slag, and others. The results are the change of compositions and characteristics of raw materials applied and a great effect on cement calcination process and clinker formation. In this work, the cement clinker formation process of different alumina-silicate raw materials to replace clay raw material was studied by chemical analysis, X-ray diffraction, differential thermal analysis, and high temperature microscope based on the characteristics of the alumina-silicate raw materials. The formation heat of the clinker was determined by the acid dissolution method. Influence of different alumina-silicate raw materials on the clinker burnability and formation process was studied. The results show that the changing of alumina- silicate raw materials, especially using industrial waste residues, can reduce the formation temperature of high temperature liquid phases, improve the burnability of raw materials, reduce the formation temperature and formation heat of clinker. And this study also observed the formation temperature and transformation of high temperature liquid phases in the heating process of raw materials by high temperature microscope.     

硅酸盐水泥熟料着色机理的研究

本文研究了用天然原料烧制彩色硅酸盐水泥熟料的可能性和途径.采用了X射线衍射、岩相、扫描电镜和定点探针能谱分析,对彩色水泥热料作了分析鉴定.根据量子化学的配位场理论建立了弱场计算方案,从理论上明确了硅酸盐水泥熟料着色的机理和原因,并对工业生产彩色水泥提出了看法.     

贝利特硫铝酸盐水泥熟料的配料计算

根据贝利特硫铝酸盐水泥的矿物组成及工艺控制要求,设定其熟料矿物由硅酸二钙（C2S）、硫铝酸钙（C4A3S—）和铁铝酸四钙（C4AF）组成,根据推导出的公式计算熟料的化学组成,然后由质量守恒原则列出方程组,求解并计算生料的配料组成。实例验证结果表明,本方法可行。     

Pollution and Prevention of Pb during Cement Calcination

Emission pollution and prevention measures of Pb during cement calcination were discussed. The content of Pb and the variation of composition were explored by means of atomic absorption spectroscopy （AAS） and X-ray diffraction. The results show that a number of Pb emits during cement calcination, F and Cl promote the emission of Pb, and Pb is enriched in kiln dust. The smaller the particle of kiln dust, the higher the content of Pb. When utilizing the raw materials with a high content ofPb, a more efficient dust collector should be used and the kiln dust should be used as the addition of cement. Pb in clinker is enriched in the intermediate phase. The reduction of silica modulus is useful to increase the solidification content of Pb in clinker. The solidification content of Pb in calcium sulphoaluminate mineral is higher than that in calcium aluminate mineral.     

钢渣彩色水泥熟料低温烧成及其性能研究

水泥窑中直接烧成的彩色熟料水泥具有成本低、色泽鲜艳、色彩稳定性好等特点.本文着重探讨了在能源紧张情况下,利用氟、硫复合矿化剂低温烧成钢渣彩色水泥熟料的可能性.通过 X 射线衍射、扫描电镜观察和红外光谱等近代测试分析技术及化学分析、常规物理力学试验方法对用水泥工业性优质原料配料和掺电炉还原钢渣配料高低温烧成彩色熟料的矿物组成、色彩情况、物理力学性能及其特性进行了分析研究.     

粉煤灰为原料的高铁水泥熟料的实验研究

本文用粉煤灰完全替代粘土原料,运用正交试验方法,探索研制符合国家标准的高强水泥熟料的最佳配料方案及煅烧制度;利用X射线衍射分析、扫描电镜及岩相检验等测试手段对所得熟料和水泥水化试样进行测试,得出了“高铁”、低温烧成的优选方案,探讨了各种因素对熟料质量的影响。     

Influence of Replacement Level of Coal-series Kaolin on Hydration of Ordinary Portland Cement by X-ray Diffraction/Rietveld Method

The influence of replacement level of calcined coal-series kaolin(CCK) on hydration of ordinary Portland cement(OPC) was studied by X-ray diffraction(XRD)/Rietveld method. X-ray diffraction/Rietveld method was used to quantify the crystalline phase composition of the hydrated samples. Additionally, the morphology of hydrated samples was observed by scanning electron microscopy(SEM). The results showed that, calcium hydroxide(CH), ettringite(AFt) and amorphous phase content in hydrated samples decreased as the replacement level of CCK increased, while AFm and str?tlingite increased, which was caused by the combination of dilute, physical and pozzolanic effects. The hydration of anhydrous cement phases was accelerated by physical effect but hindered by the retardation effect of CCK. The role of each effects was discussed in detail to analyze the mechanism of OPC hydration with CCK addition. The SEM images showed that the shortening of AFt at 1 day and the denser texture at 28 days was observed with CCK addition, which was caused by the physical and pozzolanic effects, respectively.     

CORRELATION OF THE COMPONENTS OF PORTLAND CEMENT CLINKER AND SINTERING PROCESS BY MEANS OF XRD QUANTITATIVE ANALYSIS

In this paper,the cement clinkers fromvarious industrial kilns were investigated by a superposingpeaks method for X-ray quantitative analysis(XRQA)ofclinker minerals,the results show that the clinker mineralcontents measured by XRQA method better accord with thereality of clinkers made in different conditions than theo-retic contents calculated by Bouge formula do.The mea-sured contents of C_3S of clinkers manufactured in rotarykilns are higher than theoretically calculated values,where-as,the results of clinker manufactured in shaft kilns arecontrary to that.This is because in rotary kiln,the rawmeals are fully pre-heated and have high sintering temper-ature,the clinkers are well solid-solutioned and rapidlycooled,on the contrary,owing to the struetural defects,it iseasy to exist reduing atmosphere and lower temperature inshaft kiln,moreover the cooling rate is slower,all these canevidently lead to worse clinker quality.Adding CaF_2-Ca-SO_4 complex mineralizer can remarkably modify the sinter-ing situat     

差热法测定生料煤含量的实验研究

运用差热分析折原理，对差热法测定水泥生料煤含量的方法进行研究，找到一种新的水泥生料煤含量测定方法－差热测煤法，力图为实现立窑水泥生料的均匀配料和熟料的稳定烧成，提高立窑水泥熟料质量提供可行的测热方法。     

水泥熟料形成过程中重金属价态变化分析

采用基于同步辐射光源的X射线吸收精细结构谱（XAFS）,研究了掺烧As^5＋、Cr^6＋、Cr^3＋的水泥熟料中,As和Cr在水泥熟料形成过程中价态变化行为.结果表明：掺加As^5＋和Cr^6＋的水泥生料经高温煅烧后化学价态没有发生变化,掺烧As^5＋水泥熟料中As以As^5＋的形式存在;掺烧Cr^6＋水泥熟料中Cr仅以Cr^6＋的形式存在,说明水泥生料中含有的微量Cr^3＋在煅烧过程中已完全被氧化为Cr^6＋;掺烧Cr^3＋水泥熟料中含有Cr^3＋和Cr^6＋,大部分Cr^3＋在水泥熟料形成过程中被氧化为Cr^6＋.     

铁质原料对水泥熟料矿物形成及性能的影响

利用ＸＲＤ,ＯＭ,强度测定和化学分析等方法研究了不同铁质原料对硅酸盐水泥熟料矿物形成和熟料性能的影响,结果表明,掺加铜矿渣的生料具有更好的易烧性,能增加液相量,有利于熟料烧结,并能改善熟料的岩相结构和力学性能。     

稀土尾矿对水泥熟料性能的影响

试验选用云南楚雄州某地稀土尾矿,以稀土尾矿部分取代黏土原料进行水泥熟料煅烧试验。试验结果表明:掺入稀土尾矿及铅锌矿烧成熟料中的f-CaO含量明显减少,生料的易烧性提高;其3 d、7 d和28 d抗压强度均有不同程度的提高;水泥熟料中的C3S、C3A和C4AF含量有所增加,对水泥熟料的烧成起到促进作用,有利于水泥熟料矿物的形成,尤其是熟料中的C3S增加明显。     

水泥熟料率值的最佳控制范围

石灰饱和比 (KH值 )是水泥生产中经常发生波动的一个率值 ,它直接影响到水泥的强度标号。本文通过对快速钙的跟踪测定分析 ,及时调整配料方案 ,对熟料的取样、化学成分的化验、试块强度的测定 ,最后进行计算和对比分析 ,找出水泥熟料饱和比 (KH值 )的最佳控制范围 (0 .88～ 0 .92 )。     

水泥熟料率值的最佳控制范围

石灰饱和比（KH值）是水泥生产中经常发生波动的一个率值,它直接影响到水泥的强度标号。本文通过对快速钙的跟踪测定分析,及时调整配料方案,对熟料的取样、化学成分的化验、试块强度的测定,最后进行计算和对比分析,找出水泥熟料饱和比（KH值）的最佳控制范围（0.88～0.92）。     

Multi-stage Electrostatic Separation for Recovering of Aluminum from Fine Granules of Black Dross

Separation of aluminum from fine granules of black dross, which is a waste by-product in secondary aluminum production, was investigated. The separation was performed by a multi-stage electrostatic separation method. There are three stages to complete the separation, including preliminary separation, pulse charging enhancement and secondary concentration. Chemical and mineralogical compositions of collection products were analyzed and determined by X-ray diffraction(XRD) and X-ray Fluorescence(XRF). After multistage electrostatic separation, the Al_2O_3 content of the collection products increases from 50.74% to 69.77%.The mineralogical phase analysis indicates that the final recovery of metallic aluminum phase increases from 8%to 37%, and the aluminum oxide phase increases from 20% to 26%. The research results show the multi-stage electrostatic separation method is effective for recovering of aluminum from fine granules of black dross, and upgrades the black dross to a recoverable material.     

ZnO/CeO2 复合纳米材料的Rietveld 全谱拟合物相表征

通过非均相沉淀法合成ZnO/CeO₂ 复合纳米材料,并利用XRD 粉末衍射法对其进行物相分析、Rietveld全谱拟合法对其进行结构精修。拟合结果表明,该法制备样品为六方相ZnO 与立方相CeO₂ 混合相,平均晶粒尺寸分别为20.0nm 和6.9nm,质量分数分别为28.2%及71.8%。精修结果的数值判据为Rwp=5.95%、Rexp=4.06%、GOF=1.47,数值均在正常范围且计算结果可靠。TEM 表征进一步证明计算结果可靠。研究结果表明,Rietveld全谱拟合法在研究复合纳米材料的物相比与晶粒大小时更加合理。     

Optimization of the content of tricalcium silicate of high cementing clinker

Optimization of the content of tricalcium silicate(C 3 S)of high cementing clinker was investigated.The content of free-CaO(f-CaO),mineral composite,the content of C 3 S in the clinker and the hydration product were analyzed by chemical analysis and X-ray diffraction(XRD).K Valuemethod of QXRD was selected as a quantitative analysis way to measure the content of C 3 S,and the strength of cement paste was determined.The results show that at a water cement ratio of 0.29,the strength of cement paste with 73%C ...     

氢氧化镁的制备与分散性的控制

以六水氯化镁、有机胺为原料,通过有机胺共沉淀法制备氢氧化镁,分别研究了氯化镁溶液的浓度、反应温度、添加有机胺的方式、搅拌速率对氢氧化镁晶粒分散性的影响。通过制备的氢氧化镁的沉降时间来对氢氧化镁晶粒的分散性进行初步判断,并利用X衍射分析仪、扫描电子显微镜对其形貌和物相组成进行表征和分析。实验结果表明:在搅拌速率为500 r/min下,有机胺急加入80 ℃的3.0 mol/L的氯化镁溶液中,可制备出粒径均一、晶形完整单片状结构且具有良好分散性的氢氧化镁。     

原材料对原位合成强化相结晶状态的影响

钛合金表面耐磨性能差限制了电厂重要成品部件的寿命。采用激光熔覆方法,研究了不同原料状态和稀土添加对原位合成复合TiB/TiN钛基涂层强化相粒度以及分布均匀性的影响。采用X射线衍射分析(XRD)、扫描电子显微分析(SEM)和高分辨投射分析(TEM)技术等方法研究了强化相组织形貌,得出以下结论:分别采用h-BN和纯硼酸、尿素为原料形成的Core-shell结构为原料,涂层中均原位合成TiB/TiN强化颗粒,采用非晶态BN有利于获得细小强化相组织,但强化相含量相对较少;添加CeO2有利于强化相晶粒细化以及均匀分布。