Determination of major and minor elements in nickel-chromium pig iron by X-ray fluorescence spectrometry with fusion sample preparation
In order to solve the corrosion problem of platinum crucible caused by reducing substances in nickel-chromium pig iron samples during high temperature melting,a one-step melting method was devel-oped to prepare nickel-chromium pig iron glass sheet.0.1 g of sample was weighed.The flux was added by 5.0 g of lithium tetraborate,2.0 g of lithium metaborate,and 1.5 g of lithium tetraborate covering meth-od.1.0 g of lithium carbonate was used as oxidant.After the sample was melted at 700 ℃ for 10 min and 850 ℃ for 10 min,a smooth,flat and uniform glass sheet was obtained with 500 g/L lithium bromide solu-tion as release agent.The production samples with a certain content span and a certain content gradient,which were determined by national standard methods,were used as calibration sample series to draw cali-bration curves.The overlapping corrections of iron and silicon were conducted with chromium,respective-ly.The matrix corrections of spectral lines of nickel,chromium and phosphorus were not required.The prepared glass sheet was determined by X-ray fluorescence spectrometry(XRF).Thus,a method for de-termination of total iron(TFe),nickel,phosphorus,chromium and silicon in nickel-chromium pig iron was established.The contents of TFe,nickel,phosphorus,chromium and silicon in five nickel-chromium pig i-ron samples were determined according to the proposed method,and the relative standard deviations(RSD,n=11)were between 0.13%and 1.3%.The proposed method was compared with national stand-ard methods and inductively coupled plasma atomic emission spectrometry(ICP-AES).It was found that the results were basically consistent.In the proposed method,the procedures of pre-oxidation and melting were integrated by a fully automatic melting furnace for sample preparation.The complicated wall hanging operation was not required.Moreover,it could effectively protect the crucible from corrosion.
one-step melting methodfusion sample preparationnickel-chromium pig ironX-ray fluores-cence spectrometry(XRF)major and minor elementfluxoxidant