フェロシリコン中のアルミニウムの定量分光分析法

抄録

In the process control and technical improvement of the ferrosilicon metal industry, speeding up of the determination of Al in ferrosilicon products has been a foremost requirement. For these purposes, the wet chemical analysis is tedious and lacks the rapidity required. In order to solve these problems, a quantitative spectrographic determination of Al in ferrosilicon metal was studied with some statistical techniques. The following factors were investigated in this study; excitation sources, shape of electrode, internal standard-buffer, parameters of intermittent a.c. arc, factors in the sample preparation and analytical operation, and sample quantity in sampling. The outline of the method obtained from the results of the experiments was as follows; a sample of ferrosilicon powder (500 mg) is mixed with the previously prepared internal standard-buffer (750 mg) (C:BaCl₂·2H₂O=2:1), loaded into the lower cup electrode and arced for 20 sec in an intermittent a. c. arc (interm. ratio 1/20, interm. No. 1 time/sec., resistance 20 Ω and exposure time 20 sec). The analytical line pair was Al I 3082 Å-Ba I 3072 Å. By this method, ferrosilicon samples could be analysed in 3 hours with the precision of about 6% in terms of coefficient of variation. The concentration range of Al investigated in this study was 0.1∼2.0%, but a little modification might extend this range.