30+ YEARS OF EXPERIENCE IN CARBON INDUSTRY

Electrode paste shedding refers to the phenomenon in which the working portion (in the high-temperature zone within the charge) of a sintering or sintered electrode, either surface or entire, breaks, peels off, and falls into the furnace due to insufficient strength, internal defects, or external impact. This can be compared to an underbaked cookie: if it's not baked thoroughly, the inside remains soft and easily breaks. Then, where does electrode shedding typically occur, and what does it look like?

Electrode shedding primarily occurs at the working end of the electrode, the portion within the charge and reaction zone. It typically manifests in the following ways:

1. Surface flaking: Cracks appear on the electrode surface, followed by pieces falling off.

2. Large-scale detachment: Horizontal or vertical cracks develop on the electrode, causing a large piece (possibly weighing tens or even hundreds of kilograms) to separate from the main body and fall into the furnace.

3. Tip fracture: A large section of the electrode's lower end breaks off.

Electrode paste shedding is more than just a loss of electrode material; it triggers a series of chain reactions with potentially serious consequences:

1. Disruption of furnace stability: Large carbon lumps can disrupt the normal chemical reactions and material distribution within the furnace, potentially resulting in substandard products.

2. Uneven current distribution: The electrode shape becomes irregular, preventing even current flow, causing localized overheating, further damaging the electrode, and reducing electrical efficiency.

3. Electrode upward movement: Electrode shedding shortens the effective length of the electrode. To maintain normal smelting, the electrode must be forcibly lowered, forcing the electrode paste, which should have been sintered in the cooler area, into the high-temperature zone prematurely, causing further problems.

4. Forced furnace shutdown: Severe shedding can cause the electrode to malfunction. The only solution is to shut down the furnace to remove the brittle electrode or repair it, resulting in significant financial losses.

In summary, electrode paste shedding refers to the self-baking electrodes, the heart of the submerged arc furnace, that are insufficiently strong to withstand the furnace environment due to quality issues, improper sintering process, or improper operation, leading to chipping and flaking. This is a hallmark process failure and should be avoided at all costs.