Analysis of Siliceous Refractories by Inductively Coupled Plasma Atomic Emission Spectroscopy in Combination with Microwave Sample Preparation

Resumo

In this paper, we developed a methodology for the determination of Al₂O₃, SiO₂, CaO, and Fe₂O₃ in siliceous refractories by using inductively coupled plasma atomic emission spectroscopy (ICP-AES) with microwave sample preparation in an autoclave. We proposed the composition of the acid mixture and the stepwise microwave heating regime that ensure the completeness of sample dissolution and exclude the decompression of the autoclave leading to the loss of analytes in the form of volatile compounds. Cd was anticipated to be used as an internal standard. Calibrated dependences for the determination of normalized macro- and microelements in terms of oxides by ICP-AES were obtained using the method of three standards. The correctness of the developed methodology was confirmed by the analysis of state standard samples and comparison with the results of the Al₂O₃, SiO₂, CaO, and Fe₂O₃ determination in accordance with GOST. The developed technique makes it possible to reduce both the time required for the analysis by 11 times and the consumption of concentrated acids by 8 times.