30+ YEARS OF EXPERIENCE IN CARBON INDUSTRY

Occasionally, electrode paste may clump during transportation and storage. Can clumped electrode paste still be used normally? The answer depends on the degree of clumping. If the electrode paste has slight clumping, it can be crushed and sieved first, and various indicators (such as ash content, volatile matter, and plasticity) can be tested. It can be used only after meeting the standards. If the clumping is severe (hard lumps account for more than 10%), it is not recommended to use it directly. The cause of clumping needs to be traced (such as moisture absorption during storage, uneven mixing, or compression during transportation), and the production or storage process should be adjusted.

Severe clumping of electrode paste will affect its performance and production safety. The core problem stems from the fact that clumping destroys the uniformity and process compatibility of the electrode paste:

1. Difficulty in molding and processing: Clumped electrode paste has uneven particle size. Large hard lumps cannot fill the mold evenly, easily leading to defects such as delamination, holes, and cracks during molding. The density of the pressed electrode blank is inconsistent, resulting in uneven shrinkage during subsequent firing, directly causing a decrease in the strength of the finished electrode and making it prone to breakage during use.

2. Uncontrolled Calcination Process: The concentrated distribution of volatile matter and moisture in agglomerated areas leads to rapid localized gas escape during calcination, causing blistering, cracking, and even potential explosions within the electrode. Furthermore, the significant difference in calcination rates between agglomerated and loose areas can result in insufficient sintering or excessive coking, affecting overall structural stability.

3. Decreased Conductivity: Electrode Paste clumping leads to uneven mixing of aggregate and binder within the electrode paste. The resulting carbon skeleton after calcination is discontinuous, with increased porosity and localized ash enrichment, ultimately increasing electrode resistivity and reducing conductivity. During use, the electrode heats up significantly, increasing power consumption and accelerating oxidation and wear.

4. Disrupted Production Continuity: Agglomerated electrode paste easily clogs equipment (such as silos and screw conveyors) during transport and feeding, causing interruptions in electrode feeding to the submerged arc furnace, fluctuations in electrode length within the furnace, unstable furnace conditions, decreased smelting efficiency, and even forced furnace shutdown. 

To avoid electrode caking, it is necessary to strictly control the moisture content of raw materials and accurately control the kneading parameters in actual production. Most importantly, it is necessary to avoid stress and large environmental fluctuations during storage and transportation.