AN INCREMENTAL METHOD OF X-RAY DIFFRACTION QUANTITATIVE PHASE ANALYSIS OF SAMPLESCONTAINING AMORPHOUS MATERIAL

A new method for quantitative X-ray diffraction phase analysis of a powder misture has been developed according to Popovic's doping method. The weight fraction of amorphous material in the analysed sample is obtained. For a multicomponent system in which (n-2) pure phases are added into an n-phase compnent sample and theweight fractions of all n phases can be determined by the method. The test results of confirmation agree well with the theory.

A SOLUTION OF MINIMUM NORM FOR QUANTITATIVE PHASE ANALYSIS BY STANDARDLESS X-RAY DIFFRACTION

A new expression of quantitative phase analysis by standardless X-ray diffraction has been derived using intensity matrix of vector modulus.The criterion of standardless X-ray diffraction analysis was suggested,so as to separate the diffraction pattern of every phase from that of sample.The optimal solution could be obtained by the least squares regression.

A SOLUTION OF MINIMUM NORM FOR QUANTITATIVE PHASE ANALYSIS BY STANDARDLESS X-RAY DIFFRACTION

A new expression of quantitative phase analysis by standardless X-ray diffraction has been derived using intensity matrix of vector modulus,The criterion of standardless X-ray diffraction analysis was suggested,so as to separate the diffraction pattern of every phase from that of sample.The optimal solution could be obtained by the least squares regression.

AN EXTERNAL STANDARD METHOD OF QUANTITATIVE PHASE ANALYSIS OF THE SAMPLE CONTAINING AN AMORPHOUS PHASE BY X—RAY DIFFRACTION

A new method of the quantitative phase analysis of the sample containing an amorphous phase or a standardless phase by X-ray diffraction is proposed in the paper. The addtion of a reference phase or some analytical phase to the analyzed sample is not required in this method and the experimental results are satisfactory.

MULTI-PEAK MATCH INTENSITY RATIO METHOD OF QUANTI-TATIVE X-RAY DIFFRACTION PHASE ANALYSIS

A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.

Leaching behavior of phosphorous compounds from sewage sludge ash based on quantitative X-ray diffraction analysis

Phosphorus(P)is an essential and limited resource.Incineration sewage sludge ash(ISSA)contains a high amount of P,which can be recovered using chemical leaching methods.However,the recovery ratio depends on the speciation of P and the leaching conditions.In this study,hydrochloric acid was used as a leaching agent,and the effects of the hydrochloric acid concentration,leaching time,temperature,and liquid-solid ratio on the P leaching ratio were investigated.Furthermore,the co-leaching of macro-metals Ca,Al,Fe,and Mg was analyzed.The results showed that P leached rapidly within 30 min,where the leaching rate reached more than 80%and then gradually stabilized.The leaching concentrations of Ca and Mg had a significant correlation(correlation coefficient r^(2)>0.90),and both were leached completely.Al and P had similar leaching patterns,where the leaching rates increased initially and then decreased with time at 0.2 mol/L HCl.According to X-ray diffraction analysis and Rietveld refinement,the P in ISSA was mainly present in the forms of Mg_(3)Ca_(3)(PO_(4))_(4) and AlPO_(4).When leached using 0.2 mol/L HCl at 55℃ with a liquid-to-solid ratio of 20 L/kg,the AlPO_(4) and Fe_(3)(H_(2)O)_(3)(PO_(4))_(2) in ISSA dissolved initially and then precipitated on the surface of the solid phase,thereby impeding further P leaching.

Quantitative Phase Analysis of the Calcium Silicate Slag as the Residue of Extracting Alumina from High-Alumina Fly Ash

Calcium silicate slag is the residue of process of pre-desilication alkali lime sintering applied in the high-alumina fly ash to extract the alumina.The quantitative phase analysis(QPA) of the calcium silicate slag has been performed by the Rietveld method based on the powder X-ray diffraction(XRD) with the aid of noncommercial software GSAS-EXPGUI.A known weight of crystalline internal standard(10% CaF_2) was added to the calcium silicate slag to calculate the fraction of amorphous phase and other crystalline phases on an absolute basis.Besides,the calcium silicate slag was characterized by X-ray fluorescence(XRF) and thermo gravimetric(TG) differential scanning calorimetry(DSC) to test the QPA results and investigate its other characters.Finally,the results show that the amorphous fraction is 17.5%(hereinafter,the percentages refer to the mass fraction),and the major crystalline phases detected in the calcium silicate slag consist of 23.5% Beta-Ca_2 SiO_4,10.0% bredigite,10.3% Ca_3Al_2O_6(C_3A) and 21.6% CaCO_3.

A New Method for Clay Mineral Analysis and Its Application in Geology

X-ray diffraction (XRD) peaks in a low-angle diffraction section of clayminerals, especially those of authigenic origin, have broadening and tailing features in shape.Using the five basic parameters, peak position, peak height, width, shape coefficient and asymmetry,to describe an XRD peak is more accurate, comprehensive and integrated than using only 3 of them,position, height and width. Following the concept of the five basic parameters of an XRD peak, theprogram Decoform proposed in this study provides more information in mineralogical analyses byfitting actual XRD profiles. In combination with the HW-IR plot, Decoform can he systematically andaccurately used in the comprehensive analyses of crystallinity, domain size, lattice strain andquantitative phase. It is also of value for the geological investigations of diagenesis,metamorphism, basin maturity, structural stress field and so on.

Phase diagram of the CsBr-CaBr_2 system

The phase diagram of the CsBr-CaBr2 system was re-determined by using differential thermal analysis and high ternperature and room ternperature X-ray diffraction analysis. It is concluded that there are three intermediate compounds in this system： a.congruently melting compound, CsCaBr3, with a melting point of 823℃ and two incongruently melting compounds, Cs2CaBr4 and Cs3Ca2Br7, whose peritectic points being 597℃ and 635℃, respectively. X-ray diffraction analysis indicated that compound CsCaBr3 is of slightly distorted perovskite structure.

Identification of Rare Earth Phase in the Deformed High Lead-Brasses

Deformed high lead-brasses have excellent machining characteristics and good mechanical and physicalproperties.They are widely used in mechanical,clock-watch and pen-making field.Especially,they are suit-able for deep-hole machining.Because of their worse hot-working characteristics,there exists trouble inproduction process.It is reported that the rare earth metals could improve the hot-rolling property,but themechanism is still unclear.

EQUILIBRIUM PHASE DIAGRAMS IN SYSTEM CuO-PbO-Ag

Phase equilibrium in the ternary CuO-PbO-Ag system has been investigated using differential thermal analysis(DTA),thermogravimetry(TG),scanning electron microscopy(SEM) and X-ray diffraction(XRD) techniques.In the ternary CuO-PbO-Ag system,there is a eutectic reaction CuO+PbO+Ag=L at 750℃ and a composition of 12.04 mol.% Ag,16.35 mol.% CuO and 71.61 mol.% PbO.Two miscibility gaps near the two binary tie lines PbO-Ag and CuO-Ag were detected. No binary or ternary compound was detected in the ternary system.SEM and energy dispersive spectroscopy(EDS) confirm the presence of two liquid phases and the eutectic point.

蛇纹石物相X射线衍射定量分析精密度评估方法的探讨

蛇纹石是一种重要的矿物材料和化工原料,广泛应用于化工、农业、建材、冶金及环保等领域,中国由于对蛇纹石矿开采品位要求较高,形成了较多的弃尾矿,造成了大量的浪费和环境污染。根据弃尾矿中蛇纹石的不同含量,进而生产不同的工业产品,可改善生态环境,为蛇纹石企业寻求到新的发展出路。这些工作的基础是能够对蛇纹石进行快速和精确的测定。目前蛇纹石矿石的测定方法采用行业标准《蛇纹石矿石分析方法》(HG/T 3575—2006)进行,其分析步骤繁琐,分析时间过长,现有的检测方法已不能满足市场和企业的急需,而长期以来利用X射线衍射进行的蛇纹石定量分析,其分析方法的精密度一直没有得到规范的量化控制,实验室之间的精密度比对也缺乏相应的依据。为进一步提高X射线衍射法检测蛇纹石矿物含量的水平,本文根据GB/T 6379.2—2004标准中的要求,首先通过挑选加配制共10个不同含量的样品,进行均匀性检验,当检测结果F_(实测值)均小于F_(临界值),表明试验样品是均匀的,然后选择8家实验室使用检验后合格的样品进行精密度协作试验,对得到的测试结果进行格拉布斯检验和柯克伦检验,通过检验的数据才能参与精密度参数的计算,最终获得X射线衍射标准曲线法和K值法的精密度与含量之间的数学函数关系。实验结果表明:本次协作试验的数据,全部通过格拉布斯检验和柯克伦检验,均可参与精密度参数的计算,结果也侧面证明了不同实验室不同仪器测试的结果一致性较高。精密度参数的计算结果显示:在X射线衍射标准曲线法和K值法重复性限和再现性限数据中,含量最低的样品,其重复性限和再现性限也最小,验证了X射线衍射对物相定量分析的误差主要源自于样品的均匀性误差这一特征。证实了在所有影响X射线衍射定量分析结果的因素中,样品的均匀性是最关键的因素,而其他因素产生的影响可用改变测试条件等相应方法来克服。只要样品足够均匀,就能将定量分析的误差限定在可控范围内。本文针对蛇纹石物相定量分析方法精密度的研究,可为蛇纹石物相定量分析标准方法的建立和分析方法的评价及分析质量的监控等提供依据。

Si内标-X射线衍射法定量测定铁矿中Fe_(3)O_(4)、Fe_(2)O_(3)和SiO_(2)

铁矿物相的准确定量对矿物价值评价及选冶工艺研究有重要作用,现有化学法流程复杂、效率低,X射线衍射全谱拟合法可溯源性差,结果准确性难以评价和验证。对制样条件、扫描参数、内标物选择、积分方式、重叠峰校正等进行优化选择,建立了以Si为内标,以Cu靶X射线为辐射光源,步进扫描方式获得衍射谱图,以待测相含量为横坐标,待测相与内标相峰面积比值为纵坐标的校准曲线,以曲线对铁矿中Fe_(3)O_(4)、Fe_(2)O_(3)和SiO_(2)物相进行定量的方法。结果表明,试样全部通过45μm标准筛,Si内标比例为10%,步进长度0.01°,步进时间30 s,选择对Fe_(3)O_(4)(311)、Fe_(2)O_(3)(104)、SiO_(2)(011)和Si(111)的衍射峰进行积分强度计算,可获得最优结果。在选定工作条件下,Fe_(3)O_(4)在1.07%~100%范围内线性相关系数(R2)为0.995 3,相对标准偏差(RSD)1.1%~13.2%(n=6),加标回收率99.7%~115%,检出限(LOD)4.29%;Fe_(2)O_(3)在1.51%~100%范围内线性相关系数(R2)为0.999 1,相对标准偏差(RSD)2.8%~10.6%(n=6),加标回收率87.1%~112%,检出限(LOD)2.56%;SiO_(2)在0.79%~29.72%范围内线性相关系数(R2)为0.995 7,相对标准偏差(RSD)3.2%~10.3%(n=6),加标回收率86.6%~98.9%,检出限(LOD)0.68%。方法易溯源、准确性易评价和验证,适合开展标准化检测和应用。

Quantification of flupirtine maleate polymorphs using X-ray powder diffraction

Flupirtine maleate, a pharmaceutical compound for treating psychotic disease in clinics, has seven polymorphs. Form A, with better crystal stability and bioavailability, has been widely used as the pharmaceutical crystal form. Unfortunately, it is usually found in a polymorphic mixture with form B. In this study, pure crystal forms of A and B were prepared and characterized by X-ray powder diffraction （XRPD）, Fourier transform infrared spectroscopy （FT-IR） and thermal analysis. An XRPD-based method for the quantitative determination of the amount of the flupirtine maleate polymorphs form A and form B was also established through a systematic optimization of instrumental parameters. The results of the analytical methodology validation showed that the XPRD method had a broad quantitative range of 0- 100% （w/w）, good linear relationship, with R2= 0.999, excellent repeatability and precision and low limits of detection （LoD） of 0.15% （w/w） and quantification （LoQ） of 0.5% （w/w）. The results also showed that the single-peak method was not as good as the whole pattern in reducing the influence of the preferred orientation, but this can be compensated for by a systematic optimization of instrumental parameters and validating the analytical methodology to reduce errors and obtain a good, repeatable, sensitive, and accurate method. This XRPD method can be used to analyze mixtures of flupirtine maleate polymorphs （forms A and B） quantitatively and control the quality of the bulk drug.

实验条件对X射线衍射物相定量分析结果的影响

通过实验验证了多物相试样X射线衍射定量分析的基体效应,着重研究了参比强度K值、衍射强度、混合物各物相粒度、X射线管功率等实验条件对物相定量分析结果的影响。结果表明,物相定性分析是定量分析的前提,采用积分强度、使各物相颗粒尽可能细而且均匀、采用较高的X射线管功率以及适合的扫描速率均有利于提高物相X射线衍射定量分析的准确度。

X射线衍射里特沃尔德全谱图拟合法测定粉尘中游离的SiO2

应用X射线衍射技术与Rietveld全谱图拟合法测定了粉尘中游离SiO2的含量，并同时得到粉尘样品中其它晶相和非晶相物质的含量。实验采用日本理学D／MAX2500V型X射线衍射仪，CuKα辐射带石墨单色器，管电压44kV，管电流150mA，步进扫描收集衍射数据，经Jade5．0软件定性分析，DBWS9807a软件定量分析，结果为：Rp平均等于11．29％，Rwp平均等于13．74％，Rexpected平均等于4．04％。SiO2在各样品中的含量为15．61％-37．83％；加标回收率为102．6％-119．9％；重现性测定相对标准偏差（RSD）为1．14％。结果表明：用Rietveld全谱图拟合法测定粉尘中游离SiO2的含量是一种快速、准确、方便的方法。

蒙脱石X射线衍射定量分析方法影响因素研究

蒙脱石作为万能黏土已经在24个领域100多个部门得到广泛应用,其含量的判断标准至关重要。本实验通过分析蒙脱石应用中控制蒙脱石中杂质含量的重要方法——X射线衍射定量分析方法,指出了影响目前蒙脱石X射线衍射定量分析方法的7个主要因素。

X射线衍射物相定量分析内标法标准曲线库的建立

在Rigaku D／Max-2200型X射线衍射仪（XRD）定量分析软件的基础上，制作了无机非金属材料中常用的SiO2（石英）、Al2O3（刚玉）、TiO2等9种组分用XRD采用内标法进行物相定量分析时的标准曲线。结果表明，这些标准曲线的可信度R在0．928～0.980。通过对已知含量样品的测量，分析结果与实际值一致，说明建立的标准曲线完全可用于高精度物相定量分析。

X射线衍射多谱峰匹配强度比定量相分析方法

提出了1种采用X射线衍射多谱峰匹配强度比进行定量相分析的新方法 ;该法是利用混合物样品X射线衍射谱图中的多谱峰数据 ,结合ICDD卡中的各相标准谱峰的相对强度分布数据进行最小二乘法回归分析 ,求得混合物样品中各相间的多谱峰匹配强度比 ;以多谱峰匹配强度比取代通常采用的特定单一谱线强度比 ,用于混合物样品的X射线衍射定量相分析 ,有利于提高定量相分析的精度 ;采用多谱峰匹配强度比结合绝热法和基体清洗法X射线衍射定量相分析原理 ,通过对4组分混合物样品的分析 ,证实实验结果和理论完全一致。

S Zorb吸附剂Rietveld物相定量方法研究

S Zorb技术是生产低硫清洁汽油的核心技术之一,在装置工业运行过程中发现吸附剂失活快、剂耗高等问题。为了研究吸附剂失活原因,并为国产剂的开发提供支持,利用X射线衍射(XRD)表征S Zorb工业装置中吸附剂的新鲜剂、待生剂和再生剂的晶体结构,探讨吸附剂物相变化规律,结果表明非活性锌类尖晶石的生成是导致吸附剂失活的主要因素。针对不同剂型的S Zorb吸附剂分别建立了Rietveld相定量方法,表征不同形态吸附剂晶相和非晶相物质的质量分数,并利用XRF方法表征吸附剂化学组成,进一步验证了Rietveld相定量法的准确性,利用29Si NMR表征吸附剂中Si元素的化学环境,验证Rietveld相定量法对无定型SiO2定量结果的准确性。Rietveld相定量法可广泛应用于S Zorb工业装置运行情况监控以及新剂的研究开发。