Introduction to Gypsum Drying and Calcination Process:
In the production of gypsum products, the calcination is the key step for product quality control. To acheive the quality, Dongda Powder researched and developed the One-Step and Two-Step process with some specialized equipment such as Sid calciner, Sid dryer, and internal & external fired fluizided bed furnace.
One-Step Process:
Equipment features:
The Sid calciner, which is developed by Dongda Powder Company, is an integrated
high efficiency equipment to drying, calcining, and dispersing the material, also known as one-step process equipment. It is mainly applied to calcinate gypsum through the direct heating with heat source such as coal, gas or natural gas.
Technical Process:
The gypsum filter cake undergoes a consecutive process consisting of dispersion, dehydration, calcination, and high-speed homogenization. The calcined gypsum will be discharged from the discharge valve, while the exhaust, pass the dust collector before being released. Finally, the gypsum will be conveyed to the silos.
Two-Step Process:
Performance & features:
1. Automatic control, lesser temperature change, stable product quality.2. It can be directly applied to the wet feed treatment, integrating with drying, calcining and breaking, resulting in a low operation cost. 3. Adjustable drying and calcining time. Which makes it convenient to adjust the coagulation time.4. Applicable to a serial production with a variety of heat sources by applying direct or indirect heating. The off-gas from a power plant is also an accessible heat source.
Technical Process:
The system of two-step process is composed of Sid dryer, internal & external fired fluizided bed furnace or Sid calciner. And it uses steam directly or indirectly as heat source for calcination. Dongda Powder Company, according to the user's heat source selection, determines the configuration of the system and the manner of the drying and calcining.

Application Examples:
1.Producing gypsum powder (annual output of 100,000 tons): Our company cooperated with the Huaneng Wuhan Yangluo Powder Plant to develop a desulfurization gypsum production line with an annual output of 100,000 tons. It is also the first production line of annual output 100,000 tons in the power industry of China. 2. Producing cement retarder (annual output of 200,000 tons)
3. Gypsum block process