Refractory Aggregate Mix (Custom PSD)
A Refractory Aggregate Mix is a tailor-made, dry blend of various refractory grains (aggregates) and fine powders (matrix) that is the core component of unshaped (monolithic) refractories, such as castables, gunning mixes, and ramming mixes.
The term Custom PSD refers to a mix that is engineered to a Custom Particle Size Distribution (PSD). Achieving an optimal PSD is the single most critical factor in maximizing the performance of a monolithic refractory. A custom PSD ensures the maximum packing density, which minimizes porosity, increases density, enhances strength, and provides superior resistance to slag penetration and chemical attack.
Main Function and Characteristics
A Custom PSD mix is designed to fill all available space within the refractory body, maximizing its physical integrity.
| CHARACTERISTIC | VALUE RANGE | PRIMARY REFRACTORY FUNCTION |
|---|---|---|
| Composition | Alumina, Magnesia, Silica, Spinel, etc. | Provides the bulk structure, high melting point, and chemical resistance. |
| Packing Density | MAXIMIZED | Achieved by precisely combining coarse, medium, fine, and ultra-fine particles. |
| Water Demand | MINIMIZED | Dense packing requires less water for flow (especially for ULCC castables). |
CLASSIFICATION
- Engineering Focus: Engineered Monolithic Component
- Primary Application Focus: Particle Size Distribution (Andreasen or other models). High-Performance Castables and Monolithic Linings in critical zones.
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
|---|---|---|
| Porosity | MINIMAL | High packing density leaves minimal void space, blocking liquid penetration. |
| Mechanical Strength | MAXIMIZED | Close particle contact allows for greater load-bearing capacity and hot strength. |
| Slag Resistance | SUPERIOR | Reduced open porosity directly limits slag infiltration and corrosion. |
- The Principle of Optimal Packing
Refractory aggregates are often sourced from different materials like Calcined Bauxite, Fused Alumina, Dead-Burned Magnesia, or Fused Mullite. The PSD determines how these different sized particles fit together:
- Coarse Aggregates: Provide the skeleton and resistance to high temperature and deformation.
- Intermediate Grains: Fill the voids between the coarse particles.
- Fine Powders (Matrix): Fill the remaining micro-voids and interact with the binder (cement or chemical agent) to form the bond that holds the structure together.
An optimally designed PSD follows specific mathematical models (like the Andreasen equation or Furnas model) to achieve the highest possible packing fraction (e.g., 95% volume of solid particles, 5% void space).
- Benefits in Monolithic Refractories
A custom PSD offers profound advantages, particularly in modern, high-performance castables:
- Low/Ultra-Low Cement Castables (LCC/ULCC): In these systems, the chemical bond relies heavily on the ultra-fine particle interaction. An optimal PSD is essential for maintaining the workability (flow) of the mix while drastically limiting the required water content, which improves final density and eliminates the porosity associated with water evaporation.
- Reduced Wear: Lower porosity means less area for slag to infiltrate, react, and cause wear. The mix lasts longer in the aggressive environments of the steel and cement industries.
- Customization and Services
The Custom PSD Mix is a service provided under your Process Optimization or Inspection & Audit services (Menu Item 4) where experts analyze the application and existing refractory performance to design a blend that specifically targets the unique thermal and chemical stresses of the customer’s furnace or vessel.
✨ 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. |
