基于LIBS技术的水泥粉末在线成分分析

在工业现场生产水泥的过程中,各种成分的含量直接影响着水泥的质量,因此如何快速准确地监测水泥中各个成分的含量意义重大。采用的实验方式为,将不经过任何预处理的水泥粉末直接放入位于二维移动平台上的物料盒中,通过激光诱导击穿光谱(LIBS)直接对水泥粉末表面的不同位置进行激发检测,对得到的光谱数据首先进行归一化和主成分分析等预处理操作,然后针对水泥中Ca,Si,Al,Fe,Mg五种元素,分别建立偏最小二乘(PLS)和支持向量回归(SVR)两种定量分析模型进行方法比较。此外,对比了粉末状水泥与压片式水泥两种测量方式的结果。实验结果表明,采用粉末状水泥直接测量的方式下,针对水泥样品元素浓度与所得到的光谱中特征线强度的关系,SVR方法比PLS方法更具优势,粉末状水泥直接测量的精度接近压片式测量的精度,说明LIBS技术对水泥粉末状样品直接在线测量具有可行性。

On-Line Component Analysis of Cement Powder Using LIBS Technology

In the process of cement production in the industrial field, the content of each component in the cement directly affects the quality of the cement. Therefore, it is of great significance to quickly and accurately monitor the content of each component in the cement. In this paper, the laser induced breakdown spectroscopy (LIBS) technology is used to detect the powder cement, and the powder cement are put in a two-dimensional moved platform without any pretreatment. The spectral data is processed by normalization and principal component analysis(PCA) firstly, which is used as the input of the model. In order to analyze the elements of Ca, Si, Al, Fe and Mg in cement, we build the models based on Partial least squares(PLS) and Support Vector Regression (SVR) as the comparison of methods. In addition, the comparison of measurement methods is between cement powder detection and cement tablet detection. The experimental results show that in this type of experiment, the SVR method is more advantageous than the PLS method because of the relationship between the element concentration and the strength of its characteristic line of the cement samples. The accuracy of the direct measurement of the cement powder is close to that of the tablet type, and it demonstrated the feasibility of on-line analysis of cement powder using LIBS technology under this type of experiment.