As the construction industry in the UK continues to pursue higher durability, sustainability, and performance, Metakaolin has emerged as one of the most effective supplementary cementitious materials (SCMs). Known for its high pozzolanic reactivity and refined structure, Metakaolin significantly enhances concrete and mortar performance—making it a preferred choice for modern construction and precast concrete manufacturers.
If you are looking to buy Metakaolin in the UK, Henan Superior Abrasives (HSA) offers a consistent, high-activity grade that meets international standards for both structural and architectural applications.
What Is Metakaolin?
Metakaolin is a calcined form of kaolinite clay (Al₂Si₂O₇) produced by controlled thermal activation, typically between 650°C and 850°C. This process eliminates the crystalline structure of kaolin, resulting in a highly reactive amorphous aluminosilicate material.
Chemically, it has a high SiO₂ and Al₂O₃ content, providing excellent pozzolanic properties when mixed with cementitious systems.
Metakaolin Structure
The structure of Metakaolin plays a crucial role in its performance. During the calcination of kaolin, its layered crystalline lattice is disrupted, transforming it into an amorphous, disordered aluminosilicate phase. This amorphous structure reacts readily with calcium hydroxide (Ca(OH)₂) released during cement hydration to form additional C-S-H (calcium silicate hydrate) and C-A-H (calcium aluminate hydrate) gels.
These hydrates are responsible for:
- Increased compressive and flexural strength
- Reduced permeability
- Improved durability against sulfate attack and chloride ingress
- Lower efflorescence and improved surface finish
In short, the unique Metakaolin structure gives it superior pozzolanic reactivity and micro-filling capacity, which make it ideal for high-performance concrete (HPC) and white cement formulations.
Chemical Composition and Technical Data (HSA Metakaolin)
Henan Superior Abrasives provides a premium-grade construction Metakaolin designed for European and UK cement markets.
| Parameter | Typical Value |
|---|---|
| Activity Index | 115 |
| Pozzolanic Index (mg Ca(OH)₂/g) | 1200 |
| Water Demand (%) | 105 |
| Specific Surface Area (BET, m²/g) | 10 |
| Loss on Ignition (LOI, %) | 1.0 |
| SiO₂ (%) | 52–56 |
| Al₂O₃ (%) | 41–45 |
This balance of high alumina content and controlled water demand ensures optimum reactivity and compatibility with both Portland and blended cements.
Applications of Metakaolin
Metakaolin is widely used across the UK and Europe in diverse industrial and construction sectors:
- High-Performance Concrete (HPC): Improves mechanical strength and long-term durability.
- White and Colored Concrete: Enhances brightness and surface smoothness due to low iron content.
- Precast and Architectural Concrete: Provides higher density, reduced cracking, and improved finish.
- Oil Well Cementing: Improves resistance to high temperature and aggressive environments.
- Fiber Cement Boards and GRC Products: Improves workability, adhesion, and long-term stability.
- Refractory Applications: Acts as a binding and reactive aluminosilicate phase in fire-resistant materials.
Advantages of Using Metakaolin in Cement and Concrete
- Increased Strength: Additional C-S-H formation enhances both early and long-term compressive strength.
- Reduced Permeability: Densifies microstructure and blocks capillary pores.
- Improved Workability: Optimized particle size distribution reduces water demand.
- Enhanced Chemical Resistance: Reduces chloride penetration and sulfate attack.
- Sustainability: Reduces the cement clinker factor, lowering CO₂ emissions.
Where to Buy Metakaolin in the UK
If you are searching for “where to buy Metakaolin in the UK”, HSA offers direct exports and local distribution partnerships across Europe.
Contact our sales team to request samples, test data, or pricing for high-reactivity Metakaolin.
- Email: sales@superior-abrasives.com
- WhatsApp: 86-18638638803
Difference Between Metakaolin and Silica Fume
| Category | Metakaolin | Silica Fume |
|---|---|---|
| Source / Raw Material | Obtained by calcining purified kaolin clay (Al₂Si₂O₇) at 650–850°C | By-product of silicon or ferrosilicon alloy production in electric arc furnaces |
| Main Chemical Composition | SiO₂: 52–56% Al₂O₃: 41–45% | SiO₂: 85–98% (mainly amorphous silica) |
| Structure | Amorphous aluminosilicate with plate-like, angular particles | Amorphous silica with spherical, ultrafine particles (0.1–0.3 μm) |
| Specific Surface Area (BET) | ~10 m²/g | 15,000–30,000 m²/kg (much higher fineness) |
| Color | White to light cream | Gray to dark gray |
| Pozzolanic Reactivity | High (Activity Index ~115, Pozzolanic Index ~1200 mgCa(OH)₂/g) | Very high (due to ultrafine size and high SiO₂ content) |
| Water Demand | Moderate (≈105%) | Very high (requires more superplasticizer) |
| Effect on Workability | Slightly increases water demand but keeps good flowability | Greatly reduces workability if not properly dispersed |
| Effect on Strength | Improves both early and long-term strength | Significantly enhances later strength and impermeability |
| Effect on Durability | Improves resistance to chloride, sulfate, and alkali–silica reaction (ASR) | Excellent improvement in density, impermeability, and chemical resistance |
| Additional Benefits | – Improves whiteness (suitable for white concrete) – Enhances surface finish and aesthetics | – Fills microvoids effectively – Provides superior resistance to corrosion and chemical attack |
| Main Applications | – High-performance concrete (HPC) – White or decorative concrete – Precast elements – Refractory binders | – High-strength and ultra-high-performance concrete (UHPC) – Bridges, tunnels, marine and industrial concrete – Shotcrete and repair mortar |
| Color Appearance in Concrete | Keeps concrete lighter and smoother | Makes concrete darker or grayish |
| Cost Level | Moderate | Slightly higher due to processing and purity |
Summary: Metakaolin vs Silica Fume
- Metakaolin is ideal when you need aesthetic, light-colored, and easily workable concrete with good pozzolanic activity.
- Silica fume is better suited for ultra-high-performance, dense, and chemical-resistant concrete systems.
Both materials can also be used together in advanced formulations, combining Metakaolin’s workability and brightness with Silica Fume’s extreme fineness and strength contribution.
