Multi-elemental determination of trace amounts impurities in iron ores by atomic absorption spectrometry using iron excluding method by means of 4-methyl 2-pentanone extraction

摘要

In recent year, the high quality steel products were developed by decrease of impurity elements in the steel. Generally speaking the determination of impurity elements of iron ore were performed by JIS (Japanese Industrial Standard) Method. Butthese JIS method (published in 1983) were specified that the determination limit of impurity elements in iron ores were ranged from 0.01% to 0.003%. To be suited to control of the steel production process, the determination limit of impurity elements were required to 0.001% contents level. At the same time the establishment of multi-elemental determination of impurity elements were required to the time saving on the analytical procedures.Analytical precision on the iron excluding atomic absorption method was significantly improved than the direct atomic absorption method. The determination limit at 0.001% contents level were obtained by the iron excluding atomic absorption method. Sulfate ion interfered in the atomic absorption by the molecular absorption from 200 nm to 300 nm. Therefore in the case of the pretreatment of analytical samples for the trace amounts determination the use of the sulfate reagents must be avoided in the atomicabsorption method. The improvements of the accuracy of the calibration were obtained that the standard addition method was applied to compensate of the effect on the residual iron amounts. The multi-elemental determination can be applied to the samepretreatment solution in this method.