Microsilica Suppliers
Microsilica (silica fume) is an ultrafine silica powder generated during the smelting of industrial silicon or ferrosilicon, with an average particle size of only 0.1–0.3 microns. Its primary constituent is SiO₂ (≥ 85%–99%), and it possesses extremely high reactivity and pozzolanic activity.
Zhen an Metallurgy
High Purity Microsilica SiO₂
High-purity SiO₂ (≥92–98%) for ultra-high-performance concrete, refractory, rubber, coatings, and advanced materials. Direct manufacturer pricing. Reliable global supply chain.
Content of certain elements can be customized
Size:20~600 mesh
Packaging: 1 Ton Jumbo Bag
High Purity With Low Impurity
Free Sample
Max SiO₂ Purity 98%
Product Overview of Microsilica Powder
Microsilica (also known as silica fume) is a highly reactive byproduct generated during our production of silicon metal powder; its primary constituent is amorphous silicon dioxide (SiO2). Utilizing advanced crushing, screening, and collection technologies, Zhen An Metallurgy processes silicon metal raw materials into microsilica of exceptional fineness—with a particle size distribution ranging from sub-micron to micron levels—thereby meeting the diverse requirements for high reactivity and uniformity across various industries.
As a leading global manufacturer and supplier of metallic silicon and silicon-based materials, Zhen An Metallurgy specialises in providing high-quality silicon-based products to customers worldwide and in high-demand markets. We offer silicon dioxide powder, microsilica, silica fume and metallic silicon powder. These products are available in both dense and semi-dense forms, in a range of purity grades and mesh sizes, and can be customised to meet your specific requirements.
Micro silica fume (MSF) particles are 50–100× finer than cement. This allows them to pack into the interstitial voids between cement grains — densifying the microstructure and eliminating weak zones before they can form.
This extreme fineness, combined with its high amorphous SiO₂ content (from 85% up to 98% in premium grades), makes micro silica fume one of the most reactive pozzolanic materials available.
40-70 Mesh Microsilica
50-100 Mesh Microsilica
70-120 Mesh Microsilica
500 Mesh Microsilica
800 Mesh Microsilica
800 Mesh Microsilica
When blended into concrete, refractory castables, rubber compounds, coatings, or polymer composites, it dramatically improves mechanical strength, chemical resistance, impermeability, and durability.
Unlike fly ash or slag, micro silica fume is predominantly amorphous (non-crystalline), which means it reacts rapidly with calcium hydroxide (Ca(OH)₂) released during cement hydration to form additional calcium silicate hydrate (C-S-H) — the compound responsible for concrete strength. This pozzolanic reaction is faster and more complete than in any other supplementary cementitious material.
Our products are fully compliant with ASTM C1240 and EN 13263 standard requirements.
| Parameter | Standard Grade | Premium Grade |
|---|---|---|
| SiO₂ Content | ≥ 85% | ≥ 92–98% |
| Moisture Content | ≤ 3% | ≤ 1% |
| Loss on Ignition (LOI) | ≤ 6% | ≤ 3% |
| Chloride Content (Cl⁻) | ≤ 0.1% | ≤ 0.05% |
| Sulfur Trioxide (SO₃) | ≤ 2% | ≤ 0.5% |
| Average Particle Size | 0.1–0.3 µm | 0.1–0.15 µm |
| Specific Surface Area | ≥ 15,000 m²/kg | ≥ 20,000 m²/kg |
| Bulk Density (undensified) | 130–200 kg/m³ | 150–200 kg/m³ |
| Bulk Density (densified) | 480–720 kg/m³ | 550–720 kg/m³ |
| Colour | Light/medium grey | Light grey / off-white |
Packaging Details: Waterproof Plastic woven bag, 1mt or 1.25mt big bag, and also can customize as customer required.
Delivery Time: Within 10 days of receipt of advance payment.
Available Grades & Forms
| Product Code | SiO₂ (%) | Form | Bulk Density | Primary Application | Standard |
|---|---|---|---|---|---|
| MSF-85U | ≥ 85% | Undensified powder | 130–200 kg/m³ | General-purpose concrete, grout | ASTM C1240 |
| MSF-92U | ≥ 92% | Undensified powder | 150–200 kg/m³ | High-performance concrete, HPC | EN 13263-1 |
| MSF-92D | ≥ 92% | Densified | 550–650 kg/m³ | Ready-mix, precast, site mixing | ASTM C1240 |
| MSF-95D | ≥ 95% | Densified | 600–720 kg/m³ | UHPC, oil-well cement, marine | EN 13263-1 |
| MSF-97S | ≥ 97% | Slurry (50% solids) | Liquid, 1.4 g/cm³ | Wet-spray, self-compacting concrete | Custom spec |
| MSF-98R | ≥ 98% | Refractory grade | 200–300 kg/m³ | Castables, gunning mixes, kiln linings | ISO / custom |
| MSF-WPP | ≥ 92% | Pelletised (granules) | 700–800 kg/m³ | Easy manual handling, reduces dust | ASTM C1240 |
MSF particles are 50–100× finer than cement. This allows them to pack into the interstitial voids between cement grains — densifying the microstructure and eliminating weak zones before they can form.
Amorphous SiO₂ reacts with Ca(OH)₂ (portlandite) to form additional C-S-H gel, consuming the weak, leachable crystalline calcium hydroxide and converting it into durable binder. Reaction onset is rapid: significant activity within 7 days.
Concrete incorporating 5–15% MSF by weight of cement consistently achieves 28-day compressive strengths of 80–150 MPa (normal concrete: 20–40 MPa). Ultra-high-performance concrete (UHPC) formulations reach 200+ MPa.
The filler effect combined with pozzolanic reaction eliminates capillary pores, reducing chloride permeability by up to 10× compared to plain concrete. RCPT (Rapid Chloride Permeability Test) values drop from >2000 coulombs to below 200 coulombs.
Elimination of Ca(OH)₂ and reduced porosity makes MSF-blended materials highly resistant to sulfate attack, acid rain, seawater, CO₂ carbonation, and alkali-silica reaction (ASR). Ideal for marine, industrial, and sewage infrastructure.
In refractory applications, ultra-fine SiO₂ provides exceptional bond strength at elevated temperatures. It forms low-viscosity liquid phase sintering aids while maintaining structural integrity at 1400–1800°C.
In rubber vulcanization and silicone elastomers, MSF acts as an active reinforcing filler — improving tensile strength, tear resistance, hardness, and abrasion resistance while reducing compound cost versus precipitated silica.
As an industrial byproduct recovered from smelting off-gases, silica fume is a circular material. Using MSF to replace 8–10% of cement reduces CO₂ emissions by approximately 80–100 kg per tonne of concrete produced — supporting LEED and BREEAM certification goals.
The enormous specific surface area of MSF particles adsorbs bleed water and increases paste viscosity, virtually eliminating segregation, bleeding, and plastic settlement — essential for pumped, self-compacting, and overhead concrete placement.
The applications of microsilica span multiple high-value industries, making it particularly suitable for infrastructure upgrades in developed countries, the petrochemical sector in the Middle East, and high-end construction projects in Europe and the United States.
Concrete and Construction
Microsilica is a key admixture in the production of high-performance concrete (HPC) and ultra-high-performance concrete (UHPC), typically used at a dosage of 5%–15% (by cement weight).
Specific benefits:
Strength enhancement: Can increase concrete compressive strength to 70–120 MPa or higher, with significant gains in early-age strength.
Enhanced durability: Significantly reduces permeability (chloride ion permeability coefficient can be reduced by over 70%), resists sulphate, chloride and seawater corrosion, and extends structural service life by 2–3 times.
Crack and water resistance: Fills micro-pores, reduces bleeding and segregation, and improves resistance to freeze-thaw cycles (>300 cycles).
Other benefits: Improves bond strength with reinforcing steel, reduces alkali-aggregate reaction (ASR), and lowers hydration heat (suitable for mass concrete).
Typical Project Applications:
High-rise buildings, bridges, tunnels (e.g. the Cross-Strait Tunnel project).
Offshore platforms, port terminals, nuclear power stations.
Industrial floors, airport runways, precast components.
Self-compacting concrete (SCC), enhancing workability and surface quality.
In the high-temperature, high-salinity environments of the Middle East or the severe cold regions of Europe and America, our products have helped numerous projects achieve the goal of ‘100-year durability’.
Refractory Materials Sector
Non-densified high-purity microsilica is the premier choice for high-end refractory castables and precast components.
Improves high-temperature strength and thermal shock resistance.
Reduces porosity and enhances resistance to erosion (slag and oxidation).
Used in linings for steel, metallurgical, glass and ceramic kilns, significantly extending service life.
Combined with Al₂O₃, MgO and other materials to produce low-cement or cement-free castables.
Oil and Gas Industry
Oil well cement additives: Stabilise cement slurry under high-temperature and high-pressure conditions, enhance wellbore sealing, and resist CO₂ and H₂S corrosion.
Improve the compressive strength and elastic modulus of the cement paste.
Reduce gas migration and improve cementing quality.
Suitable for deep wells, ultra-deep wells and offshore drilling platforms.
Other Emerging and Specialised Applications
- Fertilisers and Agriculture: Used as a carrier or in silicate fertilisers to enhance crop stress tolerance.
- Coatings and Rubber: Enhances mechanical properties, adhesion and abrasion resistance.
- Ceramics and Composites: Improves sintering performance and densification.
- Environmental Protection: Used as adsorbents in wastewater treatment or as soil stabilisers.
- 3D-Printed Concrete: Optimises rheology and interlayer bonding.
Whether your requirements are for standard concrete or bespoke solutions, we can provide tailored products.
Why choose Zhen An Metallurgy as your long-term partner?
30 years of production and sales experience:
Zhenan Metallurgy is located in Anyang City, Henan Province, China. It has 30 years of production experience and can produce high-quality si powder according to user requirements.
Customized according to customer needs:
Zhenan Metallurgy has its own metallurgical experts, and the chemical composition, particle size and packaging of silica fume can be customized according to customer requirements.
Worry-free delivery:
The annual output of Zhen’an metallurgical si powder is 1.5 million tons, and the spot inventory is 200,000 tons. The supply is stable and the delivery is timely.
Free samples:
Zhenan Metallurgical will give you the greatest support, and provide free silica powder samples.
Support third-party testing:
Zhenan Metallurgical has a strict quality control system. Microsilica fume has been inspected more than 3 times before leaving the factory. At the same time, we accept third-party inspections such as SGS and BV to provide you with the greatest guarantee.
Manufacturer’s strength display:
Our factory covers an area of 30,000 square meters, with a full set of modern production equipment, two large-scale production bases such as hydrometallurgy, two key laboratories and a metallurgical material testing center with 16 senior researchers.
30000(m2)
Our factory covering an area of 30,000 square meters
1500000
Annual production and sales more than 1,500,000 tons.
Professional team to provide you with better service
Zhen An Metallurgy has a high-quality talent team integrating sales, production and R&D, including 16 senior researchers, 28 professional engineers, 35 international sales personnel, 10 senior operation personnel, and more than 300 production technicians.
Zhen An metallurgical certificate display
Our products have been exported to 78 countries, and many regular customers have visited our company and factory and placed multiple orders. After one cooperation, trust has been established with us, and customers will place orders multiple times, and some will introduce new customers to us.
Microsilica Powder Export Data
What are customers have to say
Why do our customers trust us?
Powerful Factory · Advanced Production Facilities
We have our own factory with an annual production capacity of over 100,000 tons, equipped with 8 smelting furnaces and an automated crushing and screening system to achieve precise particle size control. This ensures that the entire process from raw materials to shipment is controllable, bringing price advantages and stable delivery capabilities to our customers.
Quality Assurance · Precise Control
Each batch of products is accompanied by a chemical composition analysis report (COA) and supports third-party testing by SGS, BV, etc. Through an XRF online monitoring system, we real-time control key elements such as Fe, Al, and Ca, ensuring stable impurity levels and strong consistency in the product, effectively safeguarding the stable operation of customers’ end-processes.
Professional Packaging · Worry-Free Transportation
We offer various packaging options, including 1-tonne bags, 25kg small packages, moisture-proof bags, and pallets, to meet transportation and customs clearance requirements in different regions. Packaging can be customised with multilingual labels, and special measures are taken to ensure transportation safety in high-temperature and high-humidity regions, facilitating smooth port arrival and damage-free customs clearance.
Multilingual Services · Complete Documentation
Our sales and customer service teams cover major languages such as English, Arabic, Spanish, Portuguese, Japanese, and Korean, and are familiar with customs clearance and certification systems in various countries. We support the issuance of multilingual invoices, packing lists, and certificates of origin, helping customers communicate efficiently and clear customs smoothly.
Flexible Collaboration · Meeting Diverse Needs
We support OEM/ODM customisation, various trade terms (FOB, CIF, DDP, EXW), and both small-batch trial orders and large-volume orders. We accommodate multiple payment methods (T/T, L/C, credit insurance) to provide tailored procurement solutions for global factories, traders, and SMEs. You can order with peace of mind, free from financial pressure.
Global Logistics · Efficient Delivery
We maintain close partnerships with key global ports such as Jebel Ali, Hamburg, Santos, Tokyo, and Ho Chi Minh City. We are familiar with customs clearance procedures and logistics systems in regions including the Middle East, South America, Southeast Asia, and Europe, ensuring reasonable shipping schedules, trackable shipment progress, timely delivery, and reduced delivery risks.
Credibility, Professionalism And Flexibility
About silicon metal, high purity, low impurity, stable supply. That’s what we’re here for.
What services does Zhenan provide you?
In order to meet the needs of different customers, we accept the following customization:
Customized product specifications: According to the specific needs of customers, you can provide silimon powder products with different specifications, including customized services in terms of chemical composition, size, shape, surface treatment, etc.
Customized packaging requirements: According to the specific needs of customers, you can provide different types of packaging materials and packaging methods to ensure the safety and stability of products during transportation and storage.
Customized product quality: According to the specific needs of customers, you can provide different product quality requirements, including customized services in terms of chemical composition, physical properties, surface treatment, etc.
In order to ensure the quantity and quality of the products you receive, we pay more attention to the packaging:
High pressure resistance: Our packaging has sufficient pressure resistance to withstand the pressure and impact that may occur during stacking and transportation.
Anti-shock performance: Multi-layer packaging avoids possible shock and vibration during transportation, and protects the product from damage as much as possible.
Sealing performance: add a layer of waterproof film, which has sufficient sealing performance, and can prevent air, moisture and other substances from entering the packaging, affecting the quality of raw materials.
Easy to carry: We generally use large bags that are easy to lift for packaging, which is easier to carry.
Eco-friendly and sustainable: Our packaging materials are environmentally friendly, allowing you to recycle or dispose of them safely without polluting your local environment.
If you want free samples, the process is as follows:
Contact us: Tell us your needs and contact information through the message form on the website, or send an email to our email andy@zaferroalloy.com.
Communication details: Our professional sales staff will recommend the most suitable products for you according to your needs, and ask you if you need samples. If you need samples, we will provide them to you for free.
Shipping and receipt: After the sample is shipped, we will inform you and track the logistics information of the sample to ensure that you can receive it on time.
The products provided by Zhenan Metallurgy can provide the following testing services through third-party testing agencies. These third-party testing services can provide independent, objective verification that products comply with relevant standards and regulations.
Chemical composition analysis: Chemical composition analysis can determine the content and purity of each element in metal silicon powder.
Particle size analysis: Particle size analysis can determine the particle size and particle distribution of metal silicon powder. Common particle size analysis methods include laser particle size analysis, sieving method, etc.
Observation of surface morphology: observe the surface morphology of metal silicon powder by scanning electron microscope (SEM) and other equipment to evaluate its particle shape and surface characteristics.
Physical performance test: The physical performance test of metal silicon powder includes density measurement, compaction measurement, etc., to evaluate its physical properties and processing performance.
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