The GB/T 7731.9-2008 standard specifies two methods for the determination of bismuth content in ferrotungsten: bismuth iodide photometry and Inductance coupled plasma atomic emission spectroscopy (AES). Bismuth iodide photometry is suitable for bismuth content in the range of 0.010% to 0.060%. Samples are treated with nitric acid and hydrofluoric acid, bismuth is settled with ammonium hydroxide, and its Absorbance measurement is performed at a wavelength of 450 nm. Inductance coupled plasma atomic emission spectroscopy (AES) is suitable for bismuth content in the range of 0.010% to 0.15%, providing high-precision analytical results. Both methods can be used to ensure that the bismuth content in ferrotungsten meets mass requirements.
This summary is not the original standard text and is for reference only. For accurate information, please obtain it through official channels.
| Status | Active | ||
|---|---|---|---|
| CCS | H11 | ICS | 77.100 |
| Release Date | 2008-08-19 00:00:00 | Implementation Date | 2009-04-01 00:00:00 |