Study on Determination of Material Composition in Steel Production by Polarized Energy Dispersion X-ray Fluorescence Spectrometry
|Keywords||polarized energy dispersion X-ray fluorescence spectroscopy iron ore pig iron blast furnace slag converter slag|
All kinds of material compositions in steel production influences directly costs of production and quality of product. It is very important to determine material compositions correctly and quickly. Traditional chemical analysis method has these defects:consuming a long time, big human error and high labor intensity. The thesis developed new analytical methods for four solid state materials—iron ore, pig iron, blast furnace slag and converter slag in steel production by polarized energy dispersion X-ray fluorescence spectroscopy. The paper describes the basic principle of the polarized energy dispersion X-ray fluorescence spectrum analysis method. Sample preparation, selection of polarization secondary target and correction of curve fitting work have been studied. The operation condition for the determination of four solid state materials was optimized separately. Under the optimal analytical condition, iron ore, pig iron, blast furnace slag and converter slag, four solid state materials in steel production were determined by polarized energy dispersion X-ray fluorescence spectroscopy respectively. The results were compared with those by chemical analysis method. The results indicate that sample preparation and selection of polarized secondary target are key factors influencing accuracy of the results. The conclusion is obtained from a large number of experimental data as the following:a) To ironstone samples, because of quality classification of iron ore and cost control, by the fusion method, TFe,SiO2, CaO, S,P, MgO, Al2O3 in ironstone sample were determined. Values of RSD (n=11) of seven components in ironstone were less than 3% and the analytical results obtained were consistent with those by chemical analysis method. Analysis takes about an hour. By the method pressing powder into pellet, the precision and stability of analytical results obtained weren’t satisfied on account of the mineral base effect.b) To pig iron samples, a wafer sample was casted by steel mold with high thermal conductivity. After the surface was disposed, according to the requirements of iron production process control, Si, Mn, P and Ti in pig iron sample were determined. Values of RSD (n=11) of seven components in ironstone were less than 5% and the analytical results obtained were consistent with those by chemical analysis method. The analysis takes about 15 minitues.c) Blast furnace slag is a byproduct of iron production, while converter slag is a by-product in the production of converter steelmaking. According to the requirements of the steel production process control, to blast furnace slag and converter slag samples, both were determined by the method of pressing powder into pellet. Values of RSD (n=11) of SiO2,CaO,S, MgO and Al2O3 in blast furnace slag samplewere less than 3% and the analytical results obtained were consistent with those by chemical analysis method. Values of RSD (n=11) of MgO,Al2O3,SiO2, P2O5,S, TCa,TiO2,MnO2 and TFe in converter slag sample were less than 3% and the analytical results obtained were consistent with those by chemical analysis method. Total determination time are both about 10 minitues.The studies have shown that the polarization energy dispersive X-ray fluorescence spectrometer in the steel production process of iron ore, pig iron, blast furnace slag and converter slag four kinds of materials can be determined when to replace the traditional methods of chemical analysis. The precision and accuracy both can meet production requirements. Compared with relatively expensive, larger wavelength dispersive X-ray fluorescence spectrometer, this spectrometer is cheap and small, and largely save procurement and use of cost for the enterprise. This study for the future expansion of applications of such devices also has reference significance.