Silica flour quartz powder 200 mesh SiO2 99% supplier China export

Silica flour 25kg bags export packaging China Miningsun

Miningsun · Silica Flour Export

Silica Flour Supplier China | SiO₂ ≥99% Quartz Powder 100–400 Mesh

High-purity ground quartz supplied from verified Chinese processing sources. SiO₂ ≥ 99%. Available in 100 / 200 / 325 / 400 mesh. FOB / CIF from major Chinese ports.

Supplied to oilfield cementing contractors, refractory manufacturers, ceramic and glass producers, foundries, and paint & coating formulators across the Middle East, Southeast Asia, Africa, and the Americas. Every shipment third-party tested — COA and MTC included as standard.

SiO₂ Purity ≥ 99.0% (standard) · ≥ 99.5% (high-purity)

Mesh Sizes 100 · 200 · 325 · 400 mesh (custom available)

Key Standard API Spec 10A (oil well) · GB/T 19281

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

Available Mesh Grades

Select Your Mesh Size

Silica flour is graded by fineness (mesh number). Coarser mesh for oil well cementing and refractory mixes; finer mesh for ceramics, coatings, and precision applications. Custom mesh ranges and D₅₀ particle size targets available on request.

100M

~150 µm median

Refractory & Foundry

Coarsest flour grade. Ideal as a filler in refractory castables and foundry mold coatings where coarser particle packing is desired.

Refractory castables
Foundry sand systems
Grout & mortar filler

200M

~75 µm median

Oil Well Cementing

The primary grade for oil well cementing. Prevents strength retrogression at BHST > 110 °C when blended 35–40% BWOC with Class G / H cement.

Oil & gas well cementing
Geothermal well cementing
Lightweight concrete filler

325M

~45 µm median

Ceramics & Coatings

Fine grade for ceramic glaze formulation, industrial coatings, and HPHT cementing requiring a finer slurry with improved packing efficiency.

Ceramic glaze & body
Paints & industrial coatings
HPHT well cementing

400M

~25 µm median

Glass & Precision

Finest standard grade for glass manufacturing, fiberglass, precision casting, and high-performance rubber & plastic reinforcement.

Glass & fiberglass production
Rubber & plastic filler
Epoxy flooring systems

SiO₂ ≥ 99% — High Purity Quartz Source

Ground from high-grade natural quartz ore. Standard grade ≥ 99.0% SiO₂; high-purity grade ≥ 99.5%. Low Fe₂O₃ (<0.05%) and Al₂O₃ content — essential for glass, ceramic, and electronics applications.

Prevents Cement Strength Retrogression

When blended 35–40% BWOC with API Class G or H cement, silica flour prevents the strength retrogression that occurs at bottom-hole static temperatures exceeding 110 °C — the critical additive for deep and HPHT well cementing.

Tight Particle Size Distribution

Controlled grinding and air classification ensure consistent D₅₀ and D₉₀ values batch to batch. Critical for slurry rheology in oilfield cementing and for glaze smoothness in ceramics.

Excellent Thermal & Chemical Stability

Melting point above 1,600 °C. Chemically inert — resistant to all acids except HF. Ideal for refractory applications, high-temperature kiln linings, and chemically demanding environments.

Flexible Mesh & Packaging

100 to 400 mesh standard; custom D₅₀ targets and ultra-fine micronized grades available on request. 25 kg bags, 1 MT / 1.5 MT jumbo bags (FIBC), or bulk vessel loading.

Full Export Documentation

COA, MTC, CO, MSDS, and third-party inspection (SGS / BV / CIQ) available. PSD report (laser diffraction) and XRF chemical analysis provided per shipment on request.

Technical Data

Specifications by Mesh Grade

Key chemical and physical parameters for our standard export grades. High-purity grades (SiO₂ ≥ 99.5%, Fe₂O₃ ≤ 0.02%) available for electronics, optical, and precision applications. Custom specs on request.

Parameter	100 Mesh	200 Mesh	325 Mesh	400 Mesh
Median Particle Size (D₅₀)	~120–150 µm	~60–75 µm	~35–45 µm	~20–28 µm
SiO₂ Content (min)	≥ 99.0%	≥ 99.0%	≥ 99.0%	≥ 99.0%
Fe₂O₃ Content (max)	≤ 0.06%	≤ 0.05%	≤ 0.05%	≤ 0.04%
Al₂O₃ Content (max)	≤ 0.20%	≤ 0.18%	≤ 0.15%	≤ 0.12%
Moisture Content (max)	≤ 0.5%	≤ 0.5%	≤ 0.3%	≤ 0.3%
Whiteness (min)	≥ 88	≥ 90	≥ 92	≥ 93
pH (10% suspension)	6.5 – 7.5
Bulk Density (loose, kg/m³)	900 – 1,100
Specific Gravity	2.65 g/cm³
Crystal Form	α-Quartz (crystalline)

* Typical values from production. Batch-specific COA with XRF chemical analysis and laser diffraction PSD report available on request. High-purity grade (SiO₂ ≥ 99.5%) available at premium — specify when enquiring.

Applications

Where Our Customers Use Silica Flour

From HPHT oil wells in the Gulf to fiberglass plants in Southeast Asia — silica flour's combination of purity, hardness, and chemical inertness makes it essential across multiple high-value industries.

Oil & Gas Well Cementing

35–40% BWOC addition to API Class G/H cement for BHST > 110 °C. Prevents strength retrogression and maintains low permeability in HPHT, SAGD, and geothermal wells.

Refractory Materials

Filler and binder in castable refractories, kiln linings, furnace floors, and high-temperature mortars. Provides thermal stability and volume stability at elevated temperatures.

Ceramics & Sanitaryware

Glaze formulation, clay body recipes, tiles, and sanitaryware. Controls thermal expansion, improves vitrification, and enhances surface hardness and whiteness.

Glass & Fiberglass

Raw material for container glass, flat glass, specialty glass, and fiberglass (E-glass). High SiO₂ purity and low Fe₂O₃ are critical for color-neutral glass and fiber strength.

Paints, Coatings & Sealants

Functional filler to improve abrasion resistance, surface hardness, viscosity control, and anti-sag properties in industrial and architectural coatings.

Foundry & Rubber / Plastics

Foundry mold coatings and core washes. Reinforcing filler in rubber compounds and plastic composites to enhance tensile strength, dimensional stability, and heat resistance.

Procurement Information

Packaging, Ports & Payment

Flexible packaging and incoterms to match your application, discharge facilities, and project scale. Moisture-resistant inner PE liner standard for all bags.

Packaging Options

25 kg PP woven bags with PE inner liner, palletized & shrink-wrapped
50 kg bags available on request
1,000 kg / 1,500 kg jumbo bags (FIBC) with PE liner
Bulk loading into vessel holds (500+ MT)
20' / 40' container stuffing 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)
COA with XRF analysis & PSD report per shipment
SGS / BV / CIQ third-party inspection on request

Why Buy from Miningsun

Consistent Purity. Controlled Fineness.

China's Anhui, Jiangsu, and Inner Mongolia provinces host some of the world's highest-grade natural quartz deposits. Miningsun sources from established grinding facilities with air classification and rigorous QC — delivering silica flour with consistent SiO₂ purity, tight PSD, and reliable whiteness batch after batch.

High-grade quartz source — SiO₂ ≥ 99.0% standard; ≥ 99.5% high-purity grade available
Tight PSD control — laser diffraction PSD report provided per shipment; D₅₀ tolerance ± 5 µm
All mesh grades stocked — 100, 200, 325, 400 mesh; custom micronized grades on request
Third-party tested — XRF chemical analysis + laser diffraction PSD with every COA
Stable pricing — quarterly fixed-price contracts available for oilfield and industrial buyers
Reliable lead times — 15–25 days from PO to vessel loading, consistently
Full export documentation — CO, MTC, MSDS, SGS/BV inspection, fumigation as required
Responsive sales team — quotes within 24 hours, English / Chinese supported

FAQ

Frequently Asked Questions

What is the difference between silica flour and silica sand?

Silica sand refers to granular quartz particles typically in the 100 µm to 2 mm range, used for foundry casting, water filtration, and construction. Silica flour is the same quartz material ground to a much finer particle size — 100 mesh (150 µm) down to 400 mesh (25 µm) or finer. The increased surface area of silica flour makes it reactive at high temperatures, which is why it is used in oil well cementing (to prevent strength retrogression) and in ceramic glazes. The terms "ground silica," "quartz powder," and "silica flour" are used interchangeably in most industries.

Why is silica flour added to oil well cement?

When Portland cement is exposed to bottom-hole static temperatures (BHST) above approximately 110 °C, a phenomenon called strength retrogression occurs — the calcium silicate hydrate (C-S-H) phases convert to weaker, more permeable phases, causing the set cement to lose compressive strength and become permeable. Adding silica flour (typically 35–40% by weight of cement, BWOC) provides reactive SiO₂ that reacts with the calcium hydroxide to form tobermorite and other stable high-temperature phases, maintaining compressive strength and low permeability throughout the well's service life. 200 mesh is the standard grade for most well cementing applications; 325 mesh is used for HPHT applications above 175 °C where finer particle packing is beneficial.

How do I select the right mesh size for my application?

For oil well cementing, 200 mesh is the industry standard per API Spec 10A for most well temperatures. For HPHT wells above 175 °C, 325 mesh is often specified. For ceramics and glazes, 325 mesh provides good suspension and smooth surface; 400 mesh is used for high-gloss or precision applications. For refractory castables and foundry applications, 100–200 mesh is typically preferred for better packing density. For paints, coatings, and rubber, 325–400 mesh provides the finest texture and highest surface area for reinforcement. We recommend requesting samples of two adjacent mesh sizes to conduct your own application testing before placing a bulk order.

Is crystalline silica subject to health and safety regulations?

Yes. Crystalline silica (α-quartz) is classified as a Group 1 carcinogen by IARC when inhaled as respirable dust over prolonged periods. This is an occupational health concern during dry handling, cutting, grinding, or mixing operations — not during normal use of finished products. We provide a full MSDS with every shipment detailing handling precautions, PPE requirements, and exposure limits per OSHA, EU REACH, and local regulations. Buyers are responsible for ensuring appropriate dust control measures and PPE are in place for workers handling the material. Wet handling significantly reduces exposure risk.

What is the minimum order quantity (MOQ) for silica flour?

MOQ is 1 metric ton for bagged orders (25 kg bags or jumbo bags), typically shipped as part of a full container load (FCL). A standard 20ft container holds approximately 20–22 MT of silica flour in 25 kg bags. For bulk vessel loading, minimum is 500 MT. Trial container orders are accepted for new buyers. Please specify your required mesh size, purity grade, and destination port when requesting a quote — pricing varies by mesh size and purity level.

Downloads

Technical & Compliance Documents

Available to qualified buyers upon request — please specify mesh size, purity grade, and estimated annual volume when reaching out.

Material Safety Data Sheet (MSDS)

Request Document

Certificate of Analysis (COA) incl. XRF + PSD

Request Document

Technical Data Sheet (TDS)

Request Document

Request a Quote for Silica Flour

Tell us your required mesh size, purity grade (standard / high-purity), 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