Kaolin Calcined
Kaolin Calcined is a white, aluminum-silicate material produced by heating high-purity Kaolin clay (primarily the mineral kaolinite, Al₂O₃ · 2SiO₂ · 2H₂O) to high temperatures (1000°C to 1400°C). The calcination process drives off chemically combined water and structural hydroxyl groups, converting the clay into an anhydrous, stable form consisting mainly of metakaolin and later, Mullite and a silica-rich glass phase.
Calcined Kaolin is highly valued in refractories for its low impurity content, excellent white color, and superior volume stability, acting as a high-purity base material or fine-grained matrix component.
Main Function and Characteristics
Calcined Kaolin provides a clean, chemically stable source of alumina and silica, essential for refractory matrices.
| CHARACTERISTIC | VALUE RANGE | PRIMARY REFRACTORY FUNCTION |
|---|---|---|
| Alumina (Al₂O₃) Content | ~45% | Defines its refractory grade as a pure fireclay material. |
| Purity | HIGH | Low levels of Fe₂O₃ and alkali metals (Na, K). |
| Water Absorption | LOW | Essential for use in monolithic castables to control water demand and density. |
CLASSIFICATION
- Mineralogy Focus: High-Purity Alumina-Silicate
- Primary Application Focus: Refractory Matrices, High-Purity Grog, and Ceramic Fillers.
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
|---|---|---|
| Volume Stability | EXCELLENT | Pre-calcination minimizes service shrinkage in the final product. |
| Refractoriness (PCE) | GOOD (~1750°C) | Suitable for medium-high temperature zones; limited by SiO₂ content. |
| Color/Whiteness | EXCELLENT | Required for white ceramics, glazes, and investment casting shells. |
Kaolin Calcined
- The Calcination Transformation
The thermal treatment is necessary to convert the structurally unstable kaolinite into stable ceramic phases:
- Dehydroxylation: Below 1000°C, kaolinite loses its structural water, transforming into Metakaolin (Al₂O₃ · 2SiO₂). This process is accompanied by significant shrinkage.
- Mullitization: At higher temperatures (>1200°C), the material begins to form fine, needle-like Mullite crystals and amorphous silica. Full conversion requires high heat, but the use of pre-calcined kaolin prevents the damaging volume change from occurring during the service life of the refractory product.
- Applications
Calcined Kaolin is used both as a fine refractory aggregate (grog) and as a highly effective powder component in the matrix:
- Refractory Castables and Mortars: Used as a fine filler to achieve high packing density and control the matrix chemistry. Its low impurity level is vital to maintain the high service temperature of the castable.
- Insulating Refractories: Lighter, porous grades are used in the production of Insulating Firebricks (IFB) and insulating castables, where the porous structure entraps air to reduce thermal conductivity.
- Investment Casting: A key ingredient in the slurry used to form the ceramic shells for investment casting, where its purity prevents metal contamination and its white color is necessary for process visibility.
- Technical Guidance
- Grade Selection: Refractory-grade Calcined Kaolin is differentiated by its final Al₂O₃ content and the level of contaminants (Fe₂O₃, TiO₂). Lower Fe₂O₃ content ensures higher refractoriness and a desirable white color.
- Calcined vs. Raw: Raw kaolin is used as a binder due to its plasticity, but calcined kaolin is used as an inert aggregate or filler to ensure dimensional stability and reduce the overall clay content in high-performance mixes.
✨ Customization Services
We offer product customization services, allowing you to tailor the appearance, dimensions, or specific markings of items like refractory shapes or bricks. This includes options for incorporating specific geometric requirements to ensure seamless integration into your process systems.
🔬 Sampling for Testing & Validation
Free product samples are available for thorough testing and validation. This allows you to confirm the quality, compatibility, and performance of our materials—such as specific bricks, castables, or raw materials—before committing to a full order.
💡 Expertise in Refractory Solutions
Leverage our deep expertise to receive detailed, application-specific refractory solutions. We move beyond just selling products by providing comprehensive plans that encompass material selection, installation guidance, and performance optimization to maximize the lifespan and efficiency of your high-temperature processes.
Rabatec products are exclusively manufactured in facilities that have achieved rigorous ISO certifications across Quality (ISO 9001), Environmental Management, and Occupational Health & Safety. This commitment ensures every product, from refractory bricks to specialized equipment, meets the highest global benchmarks for performance, sustainability, and workplace safety.
📦 Logistics Excellence: Shipping, Packaging, and Marking
Minimizing Risk: We manage all logistics to minimize handling touchpoints and transit shock. Our carriers are pre-vetted for their experience in transporting heavy, fragile, and sensitive industrial materials.
Traceability: Every shipment includes comprehensive documentation and tracking information, providing end-to-end visibility and ensuring precise delivery coordination for your site.
Protection is Paramount: Our packaging strictly follows industry standards to prevent damage, corner chipping, and moisture absorption—especially critical for materials like Basic Refractory Bricks and Refractory Mortars & Mixes.
Robust Palletization: Products are secured on fumigated, high-strength export pallets (e.g., 1100x950mm or similar sturdy dimensions) using heavy-duty strapping and durable protective wrapping (polyethylene sheeting, cardboard, etc.) to withstand long-distance travel and multiple loadings.
Moisture Control: Sensitive materials are protected with appropriate sealing and, where necessary, desiccants or moisture-vapor proof enclosures to maintain the product's integrity until installation.
Clear Identification: All outer packaging is clearly marked on multiple sides with large, legible text for immediate identification and safe handling.
Full Traceability: Markings include all essential data points: Product Name, Quality Grade, Batch Number, Quantity, Net/Gross Weight, Order Number, and the Final Destination/Construction Area. This ensures every pallet can be accounted for and correctly staged upon arrival.
Safety & Compliance: We adhere to all regulatory requirements for marking, labeling, and placarding—especially for any items classified as Dangerous Goods—to ensure full compliance with international and domestic transport regulations.
❓ Frequently Asked Questions (FAQ)
Question | Elaborated Answer |
Q: What is the Refractoriness Under Load (RUL) of your refractories? | A: Refractoriness Under Load (RUL) is a critical property that defines the maximum temperature our materials can withstand while under compressive stress before deforming (softening). Since we offer a wide range of materials—from Alumina-Silicate Bricks to high-performance Silicon Carbide Bricks—the RUL varies significantly. For specific product data, please refer to the product data sheet or submit a quote request for the material you are interested in. |
Q: Where are the Rabatec refractories and materials produced? | A: Our products are primarily sourced from specialized manufacturing plants in China. Crucially, these facilities have all undergone rigorous audits and achieved comprehensive ISO certifications (Quality, Environment, and Safety), ensuring that production adheres to the highest global standards for consistency and performance. |
Q: What refractory materials does the company offer? | A: We supply a comprehensive portfolio of advanced refractory solutions, including: Shaped Products: Alumina & Silica Bricks, Basic & Specialized Bricks (e.g., Magnesia), SiC & Structural Ceramics, and Precast Shapes. Monolithic Products: Refractory Castables, Mixes & Mortars. Insulation: Insulation Fibre and High-Performance Insulation Products. |
Q: How should I choose the appropriate refractory material for my application? | A: Selecting the correct refractory is paramount to process efficiency. The choice depends on three key factors: 1. Operating Environment: Maximum process temperature and thermal cycling (shock). 2. Chemical Attack: Type of slag, molten metal, or corrosive gas being handled (acidic, neutral, or basic). 3. Mechanical Stress: Abrasion, erosion, and static load requirements. We recommend utilizing our detailed refractory solutions service to consult with our engineers for an optimized, application-specific recommendation. |
Q: Which monolithic material should I choose when patching an existing lining? | A: For patching and minor repairs, the ideal monolithic material depends on the parent lining material, the patching depth, and the need for a rapid return to service. Common choices include: Refractory Mortars & Mixes (for minor joints/surfaces) or Plastic Refractories (for areas requiring physical compaction). Always choose a patch material chemically compatible with the existing lining to ensure proper bonding and service life. |
Q: Can I receive product samples before placing a major order? | A: Yes. We gladly provide product samples for your internal testing and validation purposes. This ensures you can confirm the quality, composition, and fit of the material—such as our Refractory Castables or Alumina-Silicate Bricks—in your specific operational environment before committing to a bulk purchase. |
Q: Do you provide certifications to verify material quality? | A: Absolutely. We provide product-related inspection certificates and quality assurance documentation upon request. This verifies that your order has passed all internal quality control checks and meets the required material specifications and industry standards. |
Q: What measures are taken for product protection during transport? | A: We ensure quick, reliable transport by using robust, industrial packaging that strictly follows industry standards. This includes high-strength palletization, heavy-duty strapping, and weather-resistant wrapping to protect fragile items like bricks and mixes from corner chipping, mechanical damage, and moisture during transit. |
