Gypsum Powder Production Line

About Gypsum

Gypsum is a monoclinic mineral and hydrate whose main chemical component is calcium sulfate (CaSO4). The most widely used is dihydrate gypsum.dihydrate gypsum, commonly known as raw gypsum, is an important industrial raw material. Through the calcination and grinding process, it can be converted into beta-type hemihydrate gypsum (2CaSO4·H2O), which is building gypsum (also known as plaster of paris or stucco).

It is worth noting that gypsum products with different properties can be obtained at different calcination temperatures: when the calcination temperature is controlled at 150°C, model gypsum can be produced, which is better than ordinary building gypsum in terms of fineness and whiteness; and when the calcination temperature is raised to 900-1100°C, floor gypsum can be obtained. Although this kind of gypsum sets and hardens slowly, its strength, wear resistance and water resistance after hardening are significantly better than ordinary building gypsum.

Gypsum powder production process

① Raw material preparation
Natural dihydrate gypsum (CaSO₄·2H₂O) is broken into smaller particles through a crusher to facilitate subsequent calcination and grinding processes. This step is a key link to ensure gypsum powder production efficiency and product quality.
② Calcination
The crushed gypsum particles are heated in a rotary kiln. The purpose of calcination is to convert dihydrate gypsum into hemihydrate gypsum (CaSO₄·0.5H₂O) or anhydrous gypsum (CaSO₄) by removing part of the crystal water. Depending on the calcination temperature, gypsum products with different properties can be obtained:
Low-temperature calcination (around 150°C): generates β-type semi-hydrated gypsum, which is suitable for building gypsum, model gypsum, etc., with high fineness and whiteness.
High-temperature calcination (900-1100℃): generates anhydrous gypsum, which is suitable for high-performance products such as floor gypsum. Its strength, wear resistance and water resistance after hardening are significantly better than ordinary building gypsum.
③ Grinding Process
The calcined gypsum blocks are finely ground through a ball mill to achieve the required fineness requirements.
④ Follow-up processing
The calcined and ground gypsum powder needs to go through the following processing steps: cooling → screening → packaging.