凹凸棒粘土中坡缕石的内标法X衍射定量分析研究

Quantitative Analysis of X-ray Diffraction for Palygorskite within Attapulgite Clay

用聚丙烯酸钠(PAAS)作分散剂,从凹凸棒粘土中提纯得到坡缕石纯样,再被按照5%的含量间隔将坡缕石和刚玉以及石英配比制成一系列的混和样品,采用NBS方法制成X衍射样片,扣除X射线衍射背景后计算出坡缕石110衍射峰和刚玉113衍射峰的积分强度比,以此为y轴,以坡缕石含量为x轴作图,拟合出线性方程,可用于凹凸棒粘土中坡缕石的定量分析。实例验证了该方法中定量分析线性方程的可行性,证明了粘土中非晶态物质的存在。

There is some difficulty in the XRD quantitative analysis of attapulgite clay in application to industry. Many previous methods about the quantitative analysis also have some problems in, choosing suitable inserted standard mineral and preparing samples. In this study, palygorskite is purified from attapulgite clay by sedimentation method. Dispersant sodium polyacrylate （PAAS） is used in the experiment so that the aggregation of palygorskite can be dispersed completely. Corundum and quartz are used to prepare a series of mixture samples with 5% interval of palygorskite in the experiment. In all samples, content of corundum is constantly 50%. The National Bureau Standards （NBS） method is employed to prepare the XRD samples. Ratios of integral intensity of palygorskite to that of corundum, labeled as Ip, 110/Icor,113, are calculated with the backgroud value subtracted. A plot is obtained by content of palygorskite as X axis and ratios of Ip, 110/Icor, 113 as Y axis. Linear equation is fitted according to the curve. Feasibility of the linear equation is proved by the study of three samples from Jiangsu, China and the existence of non-crystal materials in the clay is also proved indirectly. The equation can be used in application to the practical industry production.