What Are the Main Steps in a Gypsum Powder Production Line

What Are the Main Steps in a Gypsum Powder Production Line?

Introduction
Gypsum powder is widely used in construction, agriculture, and various industrial applications. Understanding the key stages of a gypsum powder production line can help project planners, plant managers, and equipment buyers make informed decisions. Hengshui Decheng Machinery & Equipment Co., Ltd. designs and supplies complete gypsum powder production systems that cover every stage from raw material handling to finished product packaging.

1. Raw Gypsum Preparation

• Receiving and Inspection
  Incoming gypsum rock or reclaimed gypsum (e.g., from flue gas desulfurization) is first inspected for moisture content, impurity levels, and particle size. Ensuring consistent raw material quality is essential to stable downstream operation.

• Crushing
  Large gypsum blocks are processed through a jaw crusher or impact crusher to reduce them to a manageable size (typically 20–50 mm). Uniform feed size improves milling efficiency and product consistency.

• Screening
  After crushing, material passes over vibrating screens to separate oversized fragments for recirculation and to remove any foreign objects. Screened gypsum proceeds to calcination.

2. Calcination (Dehydration)

• Rotary or Shaft Calciner
  Gypsum undergoes controlled heating at around 150–180 °C to drive off part of its water of crystallization, converting dihydrate gypsum (CaSO₄·2H₂O) into hemihydrate (CaSO₄·½H₂O). The choice between a rotary kiln or vertical shaft calciner depends on plant capacity and energy efficiency requirements.

• Temperature Control
  Precise temperature monitoring ensures thorough dehydration without over‑burning, which can lead to reduced reactivity or performance issues in the final powder.

3. Cooling and Storage

• Cooler Unit
  Calcined gypsum exits the calciner at elevated temperatures. A cooling conveyor or fluidized bed cooler lowers the temperature, preventing moisture absorption and minimizing caking in storage.

• Intermediate Storage Silos
  Cooled hemihydrate gypsum is held in silos equipped with aeration systems. Controlled environment storage maintains consistent moisture levels and avoids lump formation.

4. Grinding and Classification

• Raw Material Mill
  Gypsum is ground in a vertical roller mill or ball mill to achieve the desired fineness. Modern mills can produce powders with specific surface areas ranging from 300 to 1,200 m²/kg, depending on application.

• Air Classifier
  Ground material is pneumatically conveyed into an air classifier. Fine particles pass to the product circuit, while oversize particles are returned to the mill for further grinding.

• Closed‑Circuit Operation
  This arrangement ensures energy‑efficient milling and consistent particle size distribution.

5. Additive Blending (Optional)

• Performance Enhancers
  For specialized applications—such as high‑strength plasters or rapid‑setting compounds—small quantities of accelerators, retarders, or polymers may be blended. Dosing systems introduce additives into the powder stream with precise control.

• Homogenization
  A secondary mixer or ribbon blender ensures uniform distribution of all components.

6. Packaging and Dispatch

• Packing Machines
  Gypsum powder is filled into bags (25–50 kg) or bulk containers via automated weighing and filling machines. Dust‑free operations and dust collection hoods maintain a clean environment.

• Palletizing & Storage
  Filled bags are palletized and stretch‑wrapped for secure transport. Bulk powder is loaded into tank trucks or railcars through pressurized loading systems.

Conclusion
Each step in the gypsum powder production line is critical to ensuring product quality and operational efficiency. With decades of experience, Hengshui Decheng Machinery & Equipment Co., Ltd. offers turnkey solutions covering crushing, calcination, grinding, and packaging, tailored to your production targets and energy‑use requirements.