The Research Of The Ferroalloy Plasma Model By Laser-Induced

The laser-induced breakdown spectroscopy(LIBS) draws widespread concern due to its sample preparation, quick and easy operation, real-time detection of multi-elements without damage of the samples and other advantages. The plasma models of LIBS can be divided into two types of thermodynamic equilibrium model and spectrum model, among which domestic and foreign researchers’ systematic studies on the thermodynamic equilibrium model of plasma at early stage can be said to achieve a relatively perfect stage. However, the main advantage of LIBS technique lies in real-time analysis of concentrations of sample elements, indicating the spectrum models of plasma is an important direction of research development, for example, in the ferroalloy smelting process, the non-metallic elements plays a crucial role in the alloy quality. Therefore, the accuracy of spectrum model of LIBS plasma is a problem that urgently needs to be addressed.The paper firstly gives an overview on the background and status of studies of the plasma model, introduces the characteristics and properties of the thermodynamic equilibrium model and spectral models of plasma, makes a summary of the traditional calibration model, the internal calibration model and principle of free calibration models of the common models of Spectral models and uses the three models for experimental comparison with iron alloy samples. It is found in the experiment that the abnormal data existing in the lines data results into low precision in spectrum models and that abnormal data interfusion can be caused by changes experimental parameters, characteristic lines drift, overlapping lines and so on. Therefore, there should be a pre-treatment process for the spectral data for the samples before the establishment of plasma spectroscopy models, and as long as removing noise and interference, we can guarantee the accuracy of the model is not affected. The amount of non-metallic elements of ferroalloy sample is small, the characteristic line is not obvious and the spectral lines may be affected because of the iron matrix, so this paper establishes a new Spectrum model based on chemical methods, and finds after a study that, compared to the traditional spectrum models, this model has high accuracy and good stability in detecting carbon and other non-metallic elements in the alloy.