Calcium-Silicon Lumps
Calcium-Silicon Lumps (CaSi) Ferroalloy is a master alloy of calcium (Ca) and silicon (Si), typically containing 28% to 35% Ca and 60% to 65% Si. When supplied in lump form, it is used as a highly effective deoxidizer, desulfurizer, and inclusion modifier in the production of high-quality steels.2 The silicon acts as a carrier and protecting agent for the highly reactive calcium, allowing for high-efficiency addition to the molten metal.
Main Function and Components
CaSi is a multi-functional additive, benefiting from the strong deoxidizing power of both Ca and Si.
| COMPONENT | CHEMICAL FORMULA | PRIMARY FUNCTION |
| Calcium | Ca | Inclusion modification (shape control), desulfurization, and cleaning. |
| Silicon | Si | Strong deoxidizer and alloying element; serves as the carrier for Calcium. |
| CLASSIFICATION | DELIVERY METHOD | PRIMARY APPLICATION FOCUS |
| Complex Deoxidizer | Bulk Addition (Lumps) | Production of high-ductility, clean steel requiring controlled inclusion chemistry. |
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
| Inclusion Modification | CRITICAL | Converts brittle Al2O3 inclusions into soft, spherical calcium aluminates, preventing casting nozzle clogging and improving steel ductility. |
| Desulfurization | HIGH | Ca reacts with sulfur (S) to form CaS inclusions, aiding Si removal to very low levels. |
| Calcium Yield | IMPROVED | The Si sheath protects the volatile Ca during initial dissolution, leading to a higher and more consistent yield compared to pure Ca. |
Calcium-Silicon Lumps
1. Inclusion Modification and Casting
The most important function of CaSi is inclusion shape control. When aluminum (Al) is used to deoxidize steel, the resulting alumina (Al2O3) inclusions are abrasive and have a high melting point, causing them to clog the submerged entry nozzles (SEN) during continuous casting.
- Mechanism: When CaSi is added, the calcium dissolves and reacts with the alumina inclusions, converting them into liquid or semi-liquid calcium aluminate compounds at steel teeming temperatures. These liquid inclusions flow freely through the SEN, eliminating clogging, and are less damaging to the final steel properties after rolling.
2. Deoxidation and Alloying
- Deoxidation: The silicon component acts as a deoxidizer, and the combination of Ca and Si provides a powerful residual deoxidizing effect, ensuring the oxygen activity is low enough for efficient sulfur removal.
- Alloying: The silicon contributes to the final alloy chemistry, typically as an intentional strengthening element.
Delivery Method
- Lumps: The lump form is used for bulk addition to the ladle or furnace for both initial deoxidation/desulfurization and for general silicon alloying. Lumps provide a slower, more stable dissolution rate compared to powder.
- Cored Wire (Alternative): While lumps are used for bulk, CaSi powder is also frequently used in cored wire injection for the final, ultra-precise Ca trimming to achieve the exact inclusion modification required for critical steel grades.
Typical Industries and Applications
- Continuous Casting: Essential for steel grades that must be cast smoothly without nozzle clogging.
- High-Quality Steels: Production of line pipe, plate, high-strength structural, and automotive sheet steels that require excellent internal cleanliness, ductility, and formability.
Technical Guidance
- Timing: CaSi addition is critical and usually occurs after the initial bulk deoxidation (often by Al) and desulfurization steps, ensuring the slag is clean and the steel has a low initial oxygen activity.
- Calcium Yield: Despite being protected by Si, calcium is volatile. Proper addition techniques, such as plunging (for lumps) or deep injection (for cored wire), are necessary to maximize Ca recovery and ensure effective inclusion modification.
✨ 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. |
