Graphite Crucibles for Silicon Production, Cokes and Carbon Materials

Fig. Graphite product for crucible

Graphite product for crucible

 

Synthetic graphite has characteristics of high melting point, low reactivity, high conductivity, etc. Because of these it is used in various applications such as electrodes and motor brushes and it is an indispensable material for production of silicon that is used in solar cells, which has drawn global attention recently.
To produce graphite crucibles for reduction furnace, firstly cokes are ground to the suitable particle size distribution range. Then it is kneaded with pitch, and ground again to ease the molding process. The re-ground particles are charged into the molds to form block shape by isostatic press. After calcination of the blocks it is graphitized under high temperature. Graphitized blocks become the final product after processes of cutting work and purification. As mentioned in the process of making block shaped molding, three steps of powder processing are required; grinding of raw material, kneading with pitch, and grinding of the kneaded mixture. For graphitizing furnace, carbon particles handling technology is important.