Rotary Kilns for Building Ceramic Aggregates: Core Equipment for Customized High-Quality Aggregates

In the construction and building materials industry, ceramic aggregates, due to their high strength, lightweight, and permeable and thermally insulating properties, have become a core raw material for new building materials such as permeable pavements, thermal insulation mortars, and lightweight partition boards. Traditional aggregate production equipment often faces problems such as uneven firing, insufficient product strength, and high energy consumption. Rotary kilns for building ceramic aggregates are specifically designed for ceramic aggregate production. By leveraging precise temperature control, adaptability to multiple raw materials, and energy-saving technologies throughout the entire process, they enable the stable production of building ceramic aggregates with varying performance characteristics, meeting the diverse needs of the construction industry. I. Core Technologies: Laying the Foundation for High-Quality Ceramic Aggregate Production

Architectural ceramic aggregates have stringent requirements for particle strength, porosity, and color uniformity. This equipment utilizes three core technologies to overcome traditional production bottlenecks, ensuring aggregate quality and production efficiency:

1. Multi-Raw Material Adaptability and Solid Waste Synergistic Utilization Technology

Strong Raw Material Compatibility: This equipment can accommodate a variety of raw materials (or mixed raw materials) such as clay, shale, fly ash, construction debris, and ceramic waste, allowing process parameters to be adjusted based on the specific raw material characteristics. For example, when utilizing construction debris, a pre-treatment process of "crushing and impurity removal → composition adjustment → granulation" ensures uniform raw material particle size (adjustable from 5-20mm after molding) to meet subsequent firing requirements. Solid Waste Resource Integration: This equipment supports the incorporation of 30%-50% solid waste (such as fly ash and ceramic waste) into production, reducing raw material costs while complying with the "Green Building Materials" policy. The ceramic aggregate produced complies with the "Ceramic Aggregates for Construction" (GB/T 35164-2017) standard, compressive strength ≥10MPa, water absorption ≤15%.

2. Precision Temperature Control and Aggregate Quality Assurance Technology

The kiln is divided into a preheating and drying section (200-500°C), a firing section (1100-1250°C), and a holding and cooling section (800-500°C). The temperature of each section is independently controlled by a PLC system. The firing section utilizes a combination of Rotary Kiln burners (specialized high-temperature burners) and infrared thermometers to control temperature fluctuations within ±10°C, ensuring sufficient sintering of the aggregate and avoiding overburning (brittleness) or underburning (lack of strength). The kiln structure is heat-resistant and wear-resistant. The kiln lining utilizes high-alumina refractory bricks and mullite coating (customized exclusively by Rotary Kiln Refractories). It can withstand long-term temperatures exceeding 1300°C and resist abrasion from hard particles in the raw material. This results in a kiln service life of 4-6 years, minimizing maintenance downtime.

3. Full-Process Energy Saving and Consumption Reduction Technology

Tiered Flue Gas Waste Heat Recovery: Equipped with a "Vertical Preheater for Rotary Kilns" and a waste heat dryer, the high-temperature flue gas (1000-1100°C) discharged from the kiln exhaust is first used to preheat the formed aggregate billets (from room temperature to 400-500°C, reducing fuel consumption during the firing stage). The wet raw materials are then treated in a waste heat dryer (reducing moisture content to ≤15%). This saves over 30% energy compared to traditional rotary kilns and reduces production energy costs. A low-heat kiln design: A "silica-aluminum insulation layer" with a stainless steel protective layer is installed on the outside of the kiln to keep the surface temperature below 50°C, minimizing heat loss and preventing excessively high workshop temperatures, thereby improving production conditions.

II. Application Scenarios: Production of Various Ceramic Aggregates for the Construction Industry

The equipment can customize ceramic aggregates with varying properties based on building requirements, suitable for various construction scenarios, including permeability, thermal insulation, and lightweight construction. Specific applications fall into three categories:

1. Production of Ceramic Aggregates for Permeable Pavements

Product Features: Produces porous ceramic aggregates with a particle size of 5-10mm, a porosity of 20%-30%, and a water permeability coefficient ≥1.0×10⁻³m/s.

Applications: Paving permeable pavements in urban sidewalks, park trails, and parking lots. Aggregates are mixed with a binder to ensure rapid rainwater infiltration, alleviating urban waterlogging.

2. Ceramic Aggregate Production for Thermal Insulation Building Materials

Product Features: Produces lightweight ceramic aggregate (bulk density ≤ 800 kg/m³) with a thermal conductivity ≤ 0.2 W/(m・K), offering both thermal insulation and strength, and can replace traditional perlite and vermiculite. Applications: Insulation mortar, lightweight partition boards, and self-insulating blocks for building exterior wall insulation systems, reducing building energy consumption and meeting "low-carbon building" requirements.

3. Ceramic Aggregate Production for Specialty Building Materials

Product Features: Customized highly wear-resistant ceramic aggregate (wear rate ≤ 3%) and colored ceramic aggregate (red, yellow, blue, and other colors achieved by adding inorganic pigments). Applications: Highly wear-resistant flooring (e.g., factory workshops and warehouses) and landscape pavement (e.g., scenic trails and residential roads), balancing functionality and aesthetics.

4. Capacity and Project Compatibility

Small and Medium-Sized Production Lines: Single-line capacity is 50,000-200,000 tons/year, suitable for small and medium-sized building materials plants and solid waste disposal centers (using construction waste to produce aggregates);

Large-Scale Production Bases: Multiple lines can be connected in parallel, with a total capacity of 500,000-2,000,000 tons/year, meeting the large-scale production needs of large building materials groups;

Existing Line Renovation: Traditional clay brick kilns and conventional rotary kilns can be upgraded by adding a raw material pelletizing system, precise temperature control, and waste heat recovery systems. These modifications can transform them into ceramic aggregate production, reducing investment costs.

III. Operational Logic: Breaking Down the "Raw Material Pretreatment - Firing - Finished Product" Process

Equipment operation adheres to the principle of "Raw Material Matching - Precision Firing - Quality Control." The entire process is divided into six major steps to ensure stable aggregate production:

1. Raw Material Pretreatment: Ensuring Greenhouse Forming and Firing Quality

Crushing and Screening: Raw materials (such as shale and construction waste) are crushed to a particle size ≤3mm. Impurities (such as stones and metal lumps) are removed through a vibrating screen to prevent interference with subsequent forming.

Proportioning and Mixing: Based on the required aggregate properties, different raw materials are mixed in a ratio (such as clay + fly ash = 7:3). An appropriate amount of water is added (moisture content controlled at 18%-22%), and the mixture is uniformly mixed in a twin-shaft mixer to ensure consistent greenhouse composition.

Pelletizing: The mixed raw materials are fed into a pelletizer to produce spherical or cylindrical greenhouses with a particle size of 5-20mm (adjustable according to requirements). The greenhouse strength is ≥2MPa to prevent breakage during transportation.

2. Preheating and Drying: Reducing Firing Energy Consumption

The formed green bodies are conveyed via a belt conveyor into a "Vertical Preheater for Rotary Kilns." There, countercurrent heat exchange with the high-temperature flue gas at the kiln exhaust raises the green body temperature from room temperature to 400-500°C, evaporating moisture (reducing the moisture content to ≤3%). This also provides initial preheating in preparation for subsequent firing.

3. Kiln Firing: Sectional Temperature Control Ensures Aggregate Quality

Kiln Drive and Temperature Zone Control: Preheated billets enter the inclined rotary kiln body (3%-5% incline). Supported by support rollers, the kiln body rotates via a gear ring (adjustable speed from 0.5-2 rpm). The billets move axially as the kiln rotates, passing through the preheating and drying section, the firing section, and the holding and cooling section. Precise Burner Temperature Control: Rotary kiln burners (dedicated burners) are installed at the kiln head. Fuel (natural gas, pulverized coal, biomass pellets) supply is adjusted based on billet material characteristics (e.g., shale requires 1200°C, fly ash requires 1150°C), ensuring a stable temperature of 1100-1250°C in the firing section and a uniform temperature in the holding section to prevent cracking in the aggregate.

4. Cooling and Screening: Ensuring Finished Product Performance and Grading

Cooling: After firing, ceramic aggregates are discharged from the kiln outlet and enter a cooler (operating synchronously with the kiln). Countercurrent heat exchange with cold air reduces the aggregate temperature from 800°C to below 100°C, preventing high-temperature aggregate accumulation and agglomeration. Finished Product Screening: The cooled aggregates are screened on multiple layers of vibrating screens and separated by particle size (5-10mm, 10-15mm, and 15-20mm). Unqualified aggregates (such as overburned and broken particles) are returned to the raw material system for reuse, while qualified aggregates are sent to the finished product bin.

IV. Service Guarantee: A Professional Team Guides the Full Aggregate Production Cycle

As a rotary kiln manufacturer deeply engaged in the building materials equipment field, we provide a full-cycle service from concept design to operations and maintenance support, enabling efficient production:

1. Customized Solution Design

Based on the customer's raw material type (e.g., clay, construction waste), aggregate performance requirements (water permeability, thermal insulation), and production capacity planning, we provide a customized solution including equipment layout, process flow diagram (rotary kiln diagram), raw material ratio plan, and return on investment calculation. We also provide pilot testing services: We verify raw material compatibility and firing parameters in a small test kiln to ensure that aggregate quality meets standards for mass production.

2. Full-Process Installation and Commissioning

We arrange for professional engineers to install the equipment on-site, focusing on ensuring the precise assembly of the pelletizing system, temperature control device, and waste heat recovery system, ensuring smooth operation of all links. Following installation, we conduct a 168-hour continuous test run to optimize parameters such as firing temperature, kiln speed, and cooling air volume until aggregate production and quality are stable.

3. Technical Training and Long-Term Operation and Maintenance

We provide technical training to our customers' operators, covering equipment operation, parameter adjustment, and common troubleshooting, ensuring independent team operation and maintenance.

Our rotary kiln for building ceramic aggregates is not only a producer of high-quality aggregates but also a promoter of the green transformation of building materials. It not only meets the demand for high-performance aggregates in new construction projects but also achieves resource recycling through the synergistic utilization of solid waste. If you require information on the production process for specific raw materials (such as construction waste), the investment costs of equipment with different production capacities, or require production case studies from similar building materials plants, please feel free to contact us. We will provide tailored technical solutions and implementation support.