Rotary kiln, the main equipment for cement production. Powdered raw materials are sent to the kiln drum from the high end of the kiln tail drum. Due to the tilt and slow rotation of the kiln drum, the material produces a compound motion of rolling along the circumference and moving from high temperature to low temperature along the axis. The process of decomposing and firing raw materials in a kiln.
Extended data
Cement and water become plastic semi-fluids. After a period of time, the cement slurry gradually loses its plasticity and maintains its original shape. This phenomenon is called coagulation (divided into initial coagulation and final coagulation). Then enter the hardening period, and the cement strength gradually increases.
The setting time of cement is required to have a certain range in construction. If the setting is too fast, the concrete will soon lose its fluidity, which will affect the vibrating; On the other hand, if the condensation is too slow, it will affect the construction speed. Therefore, the standard stipulates that the initial setting time and final setting time of cement should be within a certain range.
The setting time is determined by using cement slurry with standard consistency under certain temperature and humidity conditions. From the time of adding water to the time when the test needle sinks into the clean slurry and is 0.5 ~ 1.0 mm away from the bottom plate, the required time is the initial setting time, at which time the clean slurry begins to lose plasticity; The final setting time is less than 65438±0.0mm when the test needle sinks into the slurry. At this time, the slurry completely loses plasticity and begins to enter the hardening period.