Gypsum Drying and Calcination Technology

Brief Introduction of Gypsum Drying and Calcination Technology

Gypsum is a monoclinic mineral and is a hydrate of calcium sulfate (CaSO4). Natural dihydrate gypsum (CaSO4·2H2O) is also called raw gypsum. After calcination and grinding, β-type hemihydrate gypsum (2CaSO4·H2O) can be obtained, which is architectural gypsum, also known as plaster of paris and plaster. Gypsum is a widely used industrial material and building material. It can be used for cement retarder, gypsum building products, model making, medical food additives, sulfuric acid production, paper filler, paint filler, etc. The microporous structure and heating dehydration of gypsum and its products make it excellent in sound insulation, heat insulation and fire resistance.

The heat treatment of gypsum is divided into drying and calcination. Drying is to remove surface water, and calcination is to remove crystal water.

Shandong Tianli Energy has been designing and manufacturing gypsum drying and calcination equipment since the year 2000. So far, more than 50 sets of gypsum drying and calcination equipment have been designed and manufactured. We have cooperated with Saint-Gobain, Grenzebach, CNBM and accumulated mature technology and equipment from years of engineering experience. We can provide customers with various types of gypsum drying and calcination production lines of 50,000-300,000MT/ year.

Tianli Energy's gypsum calcination process is divided into "one-step method" and "two-step method" as follows:

1. One-step method: adopts rotary calciner as the mainframe, both the drying and calcination of gypsum is finished in the rotary calciner.

Technology Characteristics:

(1) Good product quality, stable operation and product quality, energy saving and economy；

(2) Suitable for large-scale continuous processing; large operation flexibility (100,000-300,000 tons/year);

(3) Low energy consumption.

2. Two-step method: adopts dispersing flash dryer and rotary calciner as the mainframe, the gypsum raw material first passes through the dispersing flash dryer to remove most of the surface water (≤3%), and then enters the rotary calciner through the conveying equipment for calcination.

Technology Characteristics:

(1) It takes advantage of fast-speed drying of the dispersing flash dryer to quickly remove the surface moisture to avoid the gypsum with high moisture content from sticking to the steam heating tubes in the calciner, and then the gypsum is calcined by the rotary calciner with high-temperature steam inside the heat exchange tubes as heat source;

(2) It is beneficial to maintain the purity of gypsum by indirect heating method using steam as a heat source;

(3) Large production capacity, continuous operation, suitable for large-scale industrial production, wide range of use, operating flexibility of 100,000 to 300,000MT/year);

(4) Low energy consumption, energy saving and economy. The system is equipped with a waste heat recovery and utilization system to reduce energy consumption.

In addition to gypsum rotary drying/calcination and dispersing flash drying technology, Tianli Energy also has rich engineering performance experience in gypsum dispersing rotary drying technology, high-temperature gas rotary drying/calcination technology and paddle drying/calcination technology.