The Complete Guide to Sintered Brick Manufacturing: From Raw Materials to Finished Products

The production of sintered bricks consists of four core stages: raw material preparation, green body forming, wet brick drying, and finished product firing. Modern production lines increasingly use automated equipment—such as vacuum extrusion and single firing technology—to improve efficiency and product quality.

Raw materials determine the quality of sintered bricks. Common materials include clay, shale, coal gangue, and fly ash (a solid waste). The preparation process involves:

• Crushing & Screening

  Materials are crushed using a hammer crusher, then passed through a cage or vibrating screen to remove impurities and control particle size.

• Mixing & Aging

  The screened material is mixed with water in a twin shaft mixer and then transferred to an aging pit. Aging takes about 72 hours, which improves the plasticity and uniformity of the raw material.

• Proportion Adjustment

  Internal fuel is added based on the material’s properties to optimize sintering performance.

Forming determines the shape and density of the unfired bricks. Common methods include:

• Extrusion Forming

  (mainstream modern process) A vacuum extruder removes air from the material, increasing the strength and density of the green body.

• Press Forming

  Used for hard clays or specific brick types (paving bricks). The moisture content is kept around 10% and high pressure is applied using molds.

• Cutting & Stacking

  The extruded column is cut into standard sized bricks by a cutter. Bricks are then stacked onto kiln cars either mechanically or manually.

Drying removes moisture from the green body to prevent cracking or deformation during firing.

• Natural Drying

  (traditional method) Used for clay bricks or low grade fuel bricks, but it is inefficient and weather dependent.

• Artificial Drying

  (modern method) Most production lines use tunnel dryers or drying chambers with controlled temperature and humidity for efficient drying.

Firing is the core of sintered brick production. High temperature sinters the green body into hard, durable bricks. Main firing methods:

• Single Stage Firing (Single Firing)

  Wet bricks are directly loaded into the kiln, where drying and firing occur continuously. Suitable for coal gangue internal fuel bricks.

• Two Stage Firing (Two Firing)

  Bricks are first dried, then loaded into the kiln for firing. This allows precise temperature control and produces higher strength bricks.

After firing, bricks must be cooled slowly to avoid cracking from thermal shock. Once cooled to room temperature, they are discharged from the kiln, inspected, and stacked for storage or shipment.