Silica fume microsilica Grade 90 ASTM C1240 bulk supplier China
Silica fume bulk
Silica fume microsilica 25kg bags export packaging China
Miningsun · Silica Fume Export

Silica Fume Supplier China | ASTM C1240 Microsilica — Grade 85 / 90 / 92

Bulk and bagged microsilica supplied directly from verified Chinese production sources. ASTM C1240 / GB/T 18736 compliant. FOB / CIF from major Chinese ports.

Supplied to ready-mix plants, precast manufacturers, refractory producers, and infrastructure contractors across the Middle East, Southeast Asia, Africa, and the Americas. Every shipment third-party tested — COA and MTC included as standard.

Standards ASTM C1240 · GB/T 18736 · EN 13263
Grades Grade 85 · Grade 90 · Grade 92
Typical Use 5–15% addition by weight of cement
Form Densified & Undensified available
Packaging 25 kg bags · 1 MT / 1.5 MT jumbo · Bulk vessel
MOQ 1 MT (bagged) · 500 MT (bulk vessel)
Lead Time 15–25 days after PO confirmation
Incoterms FOB · CIF · CFR

Higher Strength & Lower Permeability

5–15% silica fume addition significantly increases compressive strength and dramatically reduces water permeability — critical for long-service-life structures.

Sulfate & Chloride Resistance

Essential for marine, coastal, and chemically aggressive environments. Specification-grade purity verified by third-party testing on every shipment.

Verified Source, Stable Supply

Long-term contracts with established Chinese production facilities. Consistent quality and reliable shipment schedules — not spot-market sourcing.

Densified & Undensified Available

Both forms stocked. Densified for easier handling and bulk transport; undensified for applications requiring maximum reactivity.

Flexible Packaging & Incoterms

25 kg bags, 1 MT jumbo bags, or bulk vessel loading. FOB, CIF, and CFR available from Tianjin, Qingdao, Shanghai, and Lianyungang.

Full Export Documentation

COA, MTC, CO, MSDS, and third-party inspection (SGS / BV / CIQ) available. All paperwork handled by our experienced export team.

Technical Data

Specifications by Grade

Three SiO₂ activity grades aligned with ASTM C1240 and GB/T 18736. Grade 90 is the most widely specified grade for ready-mix, precast, and marine concrete applications worldwide.

ParameterTest StandardGrade 85Grade 90Grade 92
SiO₂ Content (min)ASTM C1240 / GB/T 18736≥ 85%≥ 90%≥ 92%
Specific Surface AreaBET15,000 – 25,000 m²/kg
Average Particle SizeLaser Diffraction0.1 – 0.2 μm
Bulk Density (Densified)ISO 6274500 – 700 kg/m³
Pozzolanic Activity Index (min)ASTM C1240≥ 95%≥ 100%≥ 105%
Moisture Content (max)EN 196-2≤ 3%
Loss on Ignition (max)EN 196-2≤ 10%≤ 8%≤ 6%
Chloride Content (max)EN 196-2≤ 0.02%

* Typical values from production. Batch-specific COA issued with every shipment.

Applications

Where Our Customers Use Silica Fume

From offshore platforms in the Gulf to tunneling projects in Southeast Asia — microsilica is specified wherever strength, impermeability, and long service life are non-negotiable.

High-Performance Concrete

High-rise structures, long-span bridges, and infrastructure requiring C60+ mix designs.

Marine & Offshore Structures

Platforms, jetties, sea walls exposed to chloride-rich environments.

Tunneling & Shotcrete

Rapid strength gain and adhesion for tunnel linings and underground works.

Precast & Prestressed Concrete

Improved surface finish, reduced efflorescence, consistent quality at scale.

Refractory & Industrial Castables

High-temperature applications requiring bonding and thermal stability.

Oil Well Cementing

Enhanced slurry density and impermeability for demanding downhole conditions.

Procurement Information

Packaging, Ports & Payment

Flexible packaging and incoterms to match your project size and discharge facilities.

Packaging Options

  • 25 kg PP / paper bags, palletized & shrink-wrapped
  • 1,000 kg / 1,500 kg jumbo bags (FIBC) with PE liner
  • Bulk loading into vessel holds (500+ MT)
  • 20' / 40' container loading available
  • Custom private-label bagging on request

Loading Ports

  • Tianjin / Xingang Port (primary)
  • Qingdao Port
  • Shanghai Port
  • Lianyungang Port
  • Bulk vessels and container shipments arranged

Payment Terms

  • 30% T/T deposit, 70% balance against B/L copy
  • L/C at sight (irrevocable, from prime banks)
  • D/P, D/A negotiable for established buyers
  • Trial orders accepted to build long-term relationships

Documentation Provided

  • Commercial Invoice & Packing List
  • Bill of Lading (B/L)
  • Certificate of Origin (CO / Form A / FORM E)
  • Mill Test Certificate (MTC) & COA per shipment
  • SGS / BV / CIQ inspection on request
Why Buy from Miningsun

20+ Years of Export Experience

China is the world's dominant producer of silicon metal and ferrosilicon. Miningsun has direct access to consistent, high-purity microsilica from established production facilities — and the export logistics expertise to deliver it reliably, anywhere.

  • Verified production sourcing — long-term contracts with major Chinese silicon furnace operations
  • Third-party tested — ASTM C1240 / GB/T 18736 with COA on every shipment
  • Stable pricing — quarterly fixed-price contracts available for repeat buyers
  • Reliable lead times — 15–25 days from PO to vessel loading
  • Multi-port loading — Tianjin, Qingdao, Shanghai, Lianyungang
  • Export documentation — full set including CO, MTC, MSDS, fumigation as required
  • Responsive sales team — quotes within 24 hours, English / Chinese / Spanish
FAQ

Frequently Asked Questions

What is the difference between densified and undensified silica fume?
Densified silica fume has been compacted to a bulk density of 500–700 kg/m³, making it easier to handle, transport, and discharge from bulk trucks. Undensified silica fume retains its original low bulk density (150–300 kg/m³) and offers slightly higher reactivity. Both forms meet ASTM C1240 requirements. Most ready-mix producers prefer densified; refractory and specialty applications often specify undensified.
What is the typical dosage rate for silica fume in concrete?
The typical dosage is 5–15% by weight of cementitious material. For high-performance concrete (HPC), 7–10% is most common. Higher dosages (up to 15%) are used in ultra-high-performance concrete (UHPC) and refractory applications. Dosage above 15% is generally not recommended without superplasticizer adjustment.
Which grade should I specify — Grade 85, 90, or 92?
Grade 90 is the most widely specified and the best value for most concrete applications including ready-mix, precast, and marine structures. Grade 92 is recommended for ultra-high-performance concrete (UHPC), demanding marine environments, and projects where the highest pozzolanic activity index is contractually required. Grade 85 is suitable for general industrial and refractory applications where cost is a priority.
What is the minimum order quantity (MOQ) for silica fume?
MOQ is 1 metric ton for bagged orders (25 kg or jumbo bags), typically shipped as part of a full container load (FCL). For bulk vessel loading, minimum is 500 MT. Trial orders of 1–5 MT are accepted for new buyers conducting laboratory qualification. Contact us to discuss your specific volume requirements.
Can you provide a free sample before I place an order?
Yes. We provide complimentary samples of 1–2 kg for laboratory testing to qualified buyers. The buyer covers express courier costs. Samples are shipped with a full COA and TDS. Please contact our sales team with your mailing address and the grade you wish to evaluate.
Downloads

Technical & Compliance Documents

Available to qualified buyers upon request — please specify Grade and quantity when reaching out.

Request a Quote or Sample

Tell us your required grade, annual volume, destination port, and packaging preference — we'll respond with a competitive FOB/CIF price within 24 hours.

Get a Price Or email us directly: info@miningsun.com · WhatsApp: +1 814 515 0096
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