New pots boost KUBAL’s production capacity

KUBAL is now entering an intensive and important period as new pots in the Electrolysis are brought into operation. During the remainder of the year, the plan is to start up eight pots per month, an ambitious initiative that will increase the number of pots in operation and strengthen the foundation for stable, long-term production.

This is a major undertaking that requires a high level of commitment, close cooperation, and great attention to detail across the organization.

The goal is to increase the number of pots in operation from 245 to 268. This corresponds to an increase in production of approximately 28 tonnes of aluminium per day, or more than 10 000 tonnes of metal per year once the full increase has been achieved.

A major undertaking

Starting up a pot is a complex process that requires precision and a significant amount of work. The process includes activities such as lining new cathode boxes, melting the bath, and carrying out planned current reductions, all of which place high demands on the Electrolysis.

First, an old cathode box is taken out of service and replaced with a new one. The pot is then prepared by placing a bed of graphite on the cathode, after which the anodes are positioned against it. Once the current has been reduced, the equipment used for electrical isolation can be removed, and the pot enters what is known as the baking start phase.

The graphite bed acts as an electrical resistance, causing heat to build up in the cathode. During the subsequent baking period, the ramming paste in the cathode expands and contracts. This is a critical stage in which the heating must take place at the correct rate. When the internal temperature of the cathode reaches 880°C, it is ready for the next stage.

Approximately eight tonnes of molten bath and one tonne of soda are then added. The pot enters the bath period, which lasts approximately one day. During this period, the bath fills any cracks and seals the cathode. Approximately four tonnes of metal are then added, and the pot is brought into operation.

Although the pot is now operating, it takes approximately 90 days for it to reach normal operating parameters.

An ongoing process

Bringing new pots into operation is an ongoing process. The pots have a service life of approximately 2 200–2 600 days, depending, among other factors, on the conditions of the individual cathode box.

To ensure stable, long-term production, older pots must gradually be taken out of operation and replaced with new ones.

Each year, a plan and budget are established for the number of pots to be brought into operation. Maintaining a steady flow of new pots is essential to ensure that older pots can be replaced before they reach the end of their service life.

Important for the future

Having the necessary materials in place to start up new pots is a very positive development for the operation. It creates good opportunities to further develop and strengthen our production.

By gradually increasing the number of pots in operation, we are creating better conditions for increased capacity and continued positive development.

The hard work and dedication of our employees have also been an important part of making this possible. We are now entering an intensive period in which many new pots will be brought into operation.

This work requires commitment, cooperation, and great attention to detail from everyone involved.