It is stored as either a fine dry powder or wet slurry. Dry powder kiln feeds are stored in blend silos. Slurries are stored in slurry tanks which maintain a continuous agitation system. With either of these systems, batch sizes are frequently twenty-four hours worth of feed or larger. However, some dry feed systems have storage for as little as ten hours worth of raw material.
Fuel is fed in a variety of forms into cement kilns.
Coal and coke is ground to a fine powder prior to being blown into the kiln. The large quantities of these fuels purchased and stockpiled at a cement plant result in a very uniform feed. Liquids are accumulated in large batch tanks which are continuously agitated. Depending on feed rates and tank sizes, batches will last ten hours or more. Other fuels are accumulated and fed in large enough quantities to maintain uniform feedstream characteristics just as with the coal and coke.