Selective Volatilization in the dc Arc Determined with a Direct-Reading Spectrometer

Abstract

The volatilization behavior of 22 elements in a 12-A dc arc has been determined using a direct-reading spectrometer and is presented as intensity-time curves. The curves are generally complex in shape, often having more than one peak. An order of volatilization has also been determined using the same data. The order of volatilization is similar to others already published, but significant differences exist. The irregular curve shapes may be due to volatilization of more than one compound of a given element from the electrode. This phenomenon may be caused by reactions that occur in the electrode. Because of a lack of data, it was impossible to correlate specific peaks on the intensity-time curves with physical constants of the possible compounds present. Both the presence of graphite powder and the concentration of the volatilizing element have an effect on the volatilization curves.