Differences in drying processes between natural gypsum and desulfurized gypsum

  Both natural gypsum and desulfurization gypsum primarily consist of CaSO₄·2H₂O. Compared to natural gypsum, desulfurization gypsum has higher purity, finer particle size, higher moisture content, and a certain viscosity. Drying is key link in the gypsum processing technology. So, what are the differences in the drying processes for natural gypsum and desulfurization gypsum?

  Similarities:

  1. Same purpose: The purpose of drying gypsum is to remove adhered water and reduce the moisture content of gypsum to a level which is suitable for later grinding, storage, and application.

  2. Same equipment: The most common types of gypsum dryers are rotary drum dryers.

  3. Same heat source: They both can use coal, gas, oil, biomass pellets, or steam as the heat source.

  4. Same heat transfer method: Both natural gypsum dryer and desulfurized gypsum dryer achieve the purpose of drying by contacting the wet material with the high-temperature hot air generated by the hot air furnace to perform heat exchange.

  Differences:

  1. Equipment selection: 1. Equipment selection: Natural gypsum has low viscosity, while desulfurized gypsum has high viscosity and is easily adhered to the inner wall of the drum. Therefore, the drum design of the desulfurized gypsum dryer is more complicated, it requires an anti-stick dryer with scraper.

  2. Drying temperature: Natural gypsum particles are larger, resulting in slow heat transfer, so it needs a higher temperature to ensure efficient drying. However, for desulfurization gypsum drying, it needs a lower temperature, because too high temperature may cause sintering or chemical decomposition and denaturation.

  3. Drum parameters: The drying of natural gypsum usually requires higher drum rotation speed and inclination, while desulfurized gypsum requires setting a smaller speed and inclination angle to extend the drying time.

  4. Environmental dust removal: Natural gypsum particles are relatively large, generating less dust and requiring a simpler dust removal system. On the contrary, desulfurization gypsum has a fine particle size, producing large amounts of powder during the drying process, thus it need a more advanced dust removal system.

  No matter what it is natural gypsum or desulfurization gypsum, their drying processes are essentially the same, but the details of the dryer are different according to the physical properties of the raw materials. If you have any technical questions about the gypsum dryer, you can contact us at any time.