1999 Volume 85 Issue 2 Pages 102-107
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. But these 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 con-trol 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. Threrfore in the case of the pretreatmenrt of analytical samples for the trace amounts determination the use of the sulfate reagents must be avoided in the atomic absorption 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 same pretreatment solution in this method.
