What is the portland cement the the process for cement making?

Portland cement is a kind of hydraulic type cement.Hydraulic cement is any cement that hardens after being combined with water.All portland cement is made of portland cement clinker, 0 ~ 5% limestone or granulated blast furnace slag, and an appropriate amount of gypsum made of fine cement hydraulic cement. Portland cement is divided into two types: Type I Portland cement is not mixed with mixed materials, code-named PⅠ; Type II Portland cement is not mixed with limestone or granulated cement content of not more than 5% Blast furnace slag mixed materials, code-named PⅡ.

Portland cement is usually made of materials such as limestone or marl and shale or clay. The raw material is crushed ,pulverized and mixed in proper proportions for the correct chemical composition.Then the raw material is fed to a rotary kiln and is burned at a temperature of approximately 2700F. This process transforms the material into clinker.The clinker is cooled and pulverized so fine that nearly all of the powder can pass through a NO. 200 mesh sieve.