Silica Fume Microsilica
Silica Fume Microsilica is an amorphous (non-crystalline) byproduct of producing Silicon Metal or Ferrosilicon alloys in high-temperature electric arc furnaces. It is collected from the exhaust gas using specialized filtration systems.
Silica Fume is an ultra-fine powder, primarily composed of spherical Silicon Dioxide (SiO₂) particles. Its distinguishing features are its extreme fineness (typically 100 times smaller than cement particles), its high specific surface area, and its high purity (generally >85% to 98% SiO₂). These properties make it an indispensable component in Low-Cement and Ultra-Low Cement Castables (LCC/ULCC).
Main Function and Characteristics
Silica Fume acts as a highly effective micro-filler and a reactive pozzolan, dramatically increasing the packing density and hot strength of castables.
| CHARACTERISTIC | VALUE RANGE | PRIMARY REFRACTORY FUNCTION |
|---|---|---|
| Particle Size | ULTRA-FINE (~0.1 μm) | Fills sub-micron voids between larger cement and aggregate grains. |
| Purity (SiO₂) | >85% to 98% | High purity minimizes fluxing agents, maintaining refractoriness. |
| Morphology | SPHERICAL | Improves flow and workability in wet mixes. |
CLASSIFICATION
- Engineering Focus: Reactive Pozzolanic Micro-Filler – Amorphous SiO₂ spheres
- Primary Application Focus: Low-Cement Refractory Castables and High-Performance Concrete
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
|---|---|---|
| Packing Density | MAXIMIZED | Ultra-fine particles fill voids, maximizing the solid content. |
| Slag/Gas Permeability | REDUCED | Dense packing minimizes continuous channels for infiltration. |
| Hot Strength | INCREASED | Reacts with CaO to form high-strength phases, improving ceramic bonding. |
Silica Fume Microsilica
- The Physical (Micro-Filler) Role
In modern refractory castables (especially LCC/ULCC), Silica Fume is integral to achieving the desired physical properties:
- Particle Packing: Its ultra-fine size allows it to fit efficiently into the minute spaces left by the finest aggregate and cement particles, resulting in a refractory body with minimal total porosity (<5%).
- Rheology: The spherical shape and high surface area, in conjunction with chemical dispersants (plasticizers), allow the castable to maintain high flowability even with a very low water content. This low water-to-solids ratio is crucial because the evaporation of excess water during dry-out would otherwise create large, undesirable pores.
- The Chemical (Pozzolanic) Role
In Calcium Aluminate Cement (CAC) castables, Silica Fume chemically enhances the ceramic bond:
- In-Situ Reaction: During the initial heating and service firing (~800°C and above), the reactive amorphous SiO₂ in the fume reacts with the CaO content from the CAC binder and sometimes the Al₂O₃ aggregate. This reaction forms high-strength calcium aluminosilicate phases like Anorthite or Mullite, creating a dense, strong ceramic bond that maintains the refractory’s strength at high temperatures.
- Technical Guidance
- Refractory Grade: Refractory-grade Silica Fume must be high purity (>90% SiO₂) with low levels of fluxing agents (alkalis, iron) to ensure it does not compromise the ultimate service temperature of the castable.
- Handling: Due to its extreme fineness, raw Silica Fume is difficult to handle and transport. It is often supplied in a densified (compacted) or slurried form to reduce dust and improve mixing efficiency.
✨ 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. |
