Cobalt Oxide Colorants Decolorizers
Cobalt Oxide Colorants Decolorizers (CaO) is a highly stable, dark-gray to black inorganic powder derived from cobalt refining. It is one of the most potent colourants used in the ceramics and glass industries, where it produces a distinctive, deep, vibrant blue colour. In specific quantities, it is also used as a decolorizing agent in glass to counteract the yellow-green tint caused by iron impurities.
Main Composition and Oxidation States
Cobalt’s powerful colouring ability comes from its metallic ion in the melt. The final colour depends on the oxidation state (Co2+ or Co3+) and the host matrix (glass or glaze).
| CHEMICAL FORM | COMMON OXIDE | VALENCE STATE | COLOUR IN GLASS/GLAZE |
| Cobalt Oxide | CoO | Co2+ (Cobaltous) | Deep Blue (Dominant and stable) |
| Cobalt Tetroxide | CO3O4 | $Co2+ and Co3+ | Darker, black powder form |
| CLASSIFICATION | TINTING STRENGTH | PRIMARY FUNCTION |
| Colourant | EXTREME | Produces reliable, deep blue in high-temperature media. |
| Decolorizer | HIGH | Counteracts yellow-green cast in glass. |
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
| Colour Intensity | EXTREME | Very small additions (often < 0.1%) are sufficient to produce a strong colour. |
| Thermal Stability | EXCELLENT | Maintains its colour and chemical form in high-temperature firings (up to } 1400°C). |
| Reliability | HIGH | The colour outcome is highly predictable and rarely affected by furnace atmosphere. |
Cobalt Oxide Colorants Decolorizers
Colourant Function (Blue Pigment)
Cobalt Oxide is the primary source of the “Cobalt Blue” colour, renowned for its clarity and intensity across a broad range of temperatures and chemical compositions.
- Ceramic Glazes and Enamels: Used to produce a wide spectrum of blues, from light sky blue to deep royal blue. It is often mixed with other oxides (like Chromium or Manganese) to create greens, purples, or blacks.
- Glassware: Added to the glass batch to create deep blue glass for decorative items, bottles, and specialty architectural glass.
Decolorizer Function (Counter-Colour)
In high-volume glass manufacturing, the iron impurities (Fe2+) inherent in the raw silica sand create an undesirable yellow-green hue.
- Decolorization Process: Cobalt Oxide is added in trace amounts to the glass melt. The blue colour produced by the cobalt is the complementary colour to the yellow-green tint of the iron. By mixing the blue and yellow-green, the resulting colour appears neutral (colorless) to the human eye, thus “decolorizing” the glass.
- Decolorizing Note: This process is often paired with an oxidizing agent (like cerium oxide) to convert the green Fe2+ into the less-colouring Fe3+. The Cobalt then neutralizes any remaining colouration.
Typical Industries and Applications
- Ceramics: Glazes for tiles, sanitary ware, dinnerware, and artistic pottery.
- Glass Industry: Decorative glass, high-volume container glass (decolorizer), and blue optical glass.
- Catalysts: Used in various chemical processes due to its unique catalytic properties.
- Pigments: Base material for the manufacture of complex inorganic colour pigments.
Technical Guidance
- Dosage: Due to its extreme tinting power, CoO must be weighed and controlled with high precision. Standard additions are often measured in parts per million (ppm) for decolorization, and 0.05% to 2% for strong colouration. Overdosing leads to a black, opaque colour due to saturation.
- Purity: High purity is essential to ensure a reliable colour outcome and prevent the introduction of other unwanted heavy metals.
✨ 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. |
