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Electrode paste forms a self-baking electrode through sintering,the current is input into the furnace to generate an electric arc, converting electrical energy into heat energy to meet the high temperatures required for ferroalloy smelting. To ensure the electrode functions properly under the high temperatures generated by the electric arc, electrode paste needs to be added to a ferroalloy furnace during use. When heated to approximately 400 degrees, the electrode paste melts and sinter into the solid status. At 800 degrees, it combines with the ore, and the electric arc generates immense heat to smelt the ore.

Although there are no clear boundaries in the entire sintering process of the electrode paste, it can be roughly divided into three stages based on the firing temperature and location, all occurring without external pressure.

Softening Stage: At this stage, the solid electrode paste melts, resistance increases, compressive strength decreases, and the electrode paste eventually becomes entirely liquid. During this stage, the ambient temperature rises from 25℃ to 120-200℃, approximately 500mm above the conductive jaw plate.

Volatilization Stage: The electrode paste melts completely, flows along the inner cross-section of the electrode shell, fills the gaps, and ensures uniform product quality. Simultaneously, it begins to volatilize significantly, gradually thickening, and the resistance continuously decreases. The volatilization is rapid, resulting in a paste-like consistency. During this stage, the ambient temperature rises from 120-200℃ to 650-750℃, approximately at the half position.

Sintering Stage: At this stage, a small amount of volatiles continue to evaporate, and further sintering begins, significantly increasing conductivity and forming a hard, unified structure. Complete sintering occurs 200-400mm below the conductive jaw plate. The ambient temperature in this stage increases from 650-750℃ to 900-1000℃.

In a submerged arc furnace, there is a method to determine whether the electrode sintering is normal: if the surface of the electrode is grayish-white or dark instead of red, the sintering is good; if the sintering is red, it is too dry; if it is black or produces a lot of smoke, the sintering is too soft.