The invention relates to a process for making graphite electrodes, and more particularly to a process for converting carbon blanks into graphite electrodes. Still more particularly, the invention relates to a process for graphitizing dimensionally stable carbon blanks.
It is known to convert dimensionally stable carbon blanks into graphite electrodes in an apparatus wherein carbon blanks of identical size and shape are stacked on top of each other and the resulting file or column is conveyed within an insulating jacket through a heating section wherein electric current is passed through the blanks to heat the blanks to graphite temperature. The thus heated blanks are thereupon cooled to complete their conversion into graphite electrodes.
German Pat. No. 23 11 467 discloses a process which includes the step of surrounding the carbon blanks in the heating section with particles of carbon black. A drawback of the patented process is that the particles of carbon black contaminate the apparatus and that expensive additional equipment is needed for introduction and confinement of such particles. Moreover, the heat energy which is used to heat the blanks is dissipated.