After the coke is discharged from the furnace, it must be quenched quickly within a very short time, so that its temperature can be rapidly cooled from 1400℃ to normal temperature. This operation is called coke quenching. The basic requirement of coke quenching is that the moisture content should be low and stable without red coke. The key of coke quenching is to isolate the red coke from the air as soon as possible, to achieve suffocation and fully contact with the medium for rapid cooling down. There are two types of coke quenching processes: dry quenching and wet quenching.
The initial moisture content of wet quenched coke is usually relatively high, so they are stored in the open field for drying. Once it rained in the drying process, the moisture content on the surface of the coke will be increased, so the coke’s moisture content before loading is largely dependent on the weather conditions. If the weather is continuously sunny before loading, then the moisture content of the batch of foundry coke will be relatively low. On the contrary, if it rains suddenly before or during loading, the moisture content on the surface of the already dry foundry coke will increase significantly, and it will appear a relatively dark color and, undoubtedly, a wet appearance.
Sometimes even the weather forecast is very difficult to be accurate. For several containers loaded in a batch, if rainy days are encountered a few days before loading, it is difficult to ensure that the moisture content of each container is kept at a relatively average level. It is possible that the foundry coke of some containers is relatively dry, while that of other containers appears wet.