For the blast furnace, the furnaceman needs a highly carbonaceous raw material that will remove oxygen from the iron ore and is able to generate the enormous heat required for the melting process. In the coking plant, coal is converted into coke by heating it for 16 to 18 hours to a temperature of 1200°C under exclusion of air. Coke has a high carbon content, high solidity and is porous, so it is able to respond well with the gas that flows through the blast furnace.
The first coke ovens were heated in Völklingen in 1897. The steel sheet coal silo that towers over the coking plant dates back to the same period. The silo is one of the oldest surviving buildings at the Völklingen Ironworks.
The front one of the two coal towers was built of steel sheet in 1897, which makes it one of the oldest buildings at the World Heritage Site Völklingen Ironworks. In the early days of the coking plant, the coal tower was filled by means of a steam-powered lift. The coke coal was tapped into wagons from the old coal tower and then laboriously transported by hand. The new concrete coal tower was built between 1941 and 1943. The coke coal could be loaded directly into the ramming machine from this coal tower. There were a total of four coal towers for the interim storage of coal at the Völklingen coking plant.