Söderberg electrode paste

Elkem Carbon has developed a variety of electrode paste qualities for use in smelting processes world-wide. The properties of the baked electrode for a specific process requires a tailor made electrode paste to suit the conditions of the operating environment. This is crucial to ensure a successful operation.

Customer value

In addition to providing process adapted electrode paste, Elkem Carbon assists with electrode audits and training seminars for proper understanding of the customer’s electrode processes: 

  • Problem solving
  • Training and optimisation of electrode management
  • Theory and main principles
  • Paste handling and charging
  • Shut down and start-up procedures
  • Casing/welding recommendations  

Elkem Carbon has developed several mathematical tools covering various aspect of the process. Both temperatures and thermal stresses can be calculated during dynamic conditions.  

Applications

Carl Wilhelm Søderberg was the first person having the idea of a selfbaking electrode system made from a carbon based paste. The industry at that time used expensive and less available graphite and prebaked electrodes.  Few years after the technology could be applied in industrial scale and with the first patent in 1919 Elkem made the foundation for the growth in the coming decades. Today, almost 100 years later it is still the most commonly used electrode system in submerged-arc furnaces for ferroalloys, platinum smelting, and slag cleaning operations.

The Søderberg electrode paste is added within the metal casing on the top of the electrode column above the furnace. As the electrode in the furnace processes is consumed, the added paste melts and bakes into a solid and electrically conductive electrode. In this way we have a continuous electrode that can do the job of transferring the energy to the hearth of the furnace where the raw materials are heated up sufficiently to meet the needed process temperatures. 

The size of the furnaces and electrodes has increased over the years and electrode diameters up to 2100 mm are today in use. Such large electrodes can be challenging to manage, and large electrodes are also more demanding when it comes to the electrode paste used in the electrodes. With the everlasting need to improve furnace operations, it is essential with advanced electrode management.