Amorphous Silica Diatomaceous Earth Powder
Amorphous Silica Diatomaceous Earth Powder
Amorphous silica diatomaceous earth (DE) powder originates from the fossilized silica shells of diatoms, microscopic aquatic organisms. The resulting material is chiefly non‑crystalline SiO₂, typically containing 85‑95 % silicon dioxide with minor constituents such as Al₂O₃, Fe₂O₃, and alkali oxides that reflect the geological source.
Chemical and Physical Characteristics
Bulk density generally ranges from 0.30 to 0.45 g cm⁻³, depending on particle shape and compaction history. Specific surface area measured by BET analysis falls between 15 and 30 m² g⁻¹, providing ample adsorption capacity for liquids and gases. The powder exhibits a neutral to slightly alkaline pH (7‑9) in aqueous suspension and a loss on ignition (LOI) below 5 % at 1000 °C, indicating minimal organic content.
Particle size distribution is commonly described by D₁₀, D₅₀, and D₉₀ values obtained via laser diffraction. Typical D₅₀ lies between 5 and 15 µm, with a span (D₉₀‑D₁₀)/D₅₀ of 1.5‑2.5, reflecting a moderately broad distribution suitable for both filtration and filler applications. Moisture content after standard drying is usually under 0.5 % by weight.
Typical Industrial Applications
In liquid filtration, the porous microstructure of DE particles creates a tortuous path that captures fine particulates while maintaining high flow rates, making it effective for beverage clarification, swimming‑pool water treatment, and industrial effluent polishing.
As an absorbent, DE can retain up to 1.5 times its weight in oils, solvents, or hazardous spills, offering a low‑density, inert medium for containment and cleanup operations. Its abrasiveness is mild, allowing use as a polishing agent in metal‑finishing without excessive substrate wear.
When employed as a functional filler in polymers, coatings, or elastomers, the amorphous silica contributes to reinforcement, rheology modification, and barrier improvement without inducing crystallinity that could affect transparency. The low surface activity reduces interference with curing systems compared to crystalline silica.
- Beverage and liquid filtration
- Oil and chemical spill absorbents
- Polishing and buffing compounds
- Reinforcing filler in plastics and coatings
- Carrier for pesticides and fertilizers
Technical Specification Table
| Parameter | Typical Value | Notes |
|---|---|---|
| Silicon Dioxide (SiO₂) | 85‑95 % | Amorphous phase, loss on ignition <5 % |
| Aluminum Oxide (Al₂O₃) | 2‑6 % | Origin‑dependent |
| Iron Oxide (Fe₂O₃) | 0.5‑2 % | Affects color tint |
| Bulk Density | 0.30‑0.45 g cm⁻³ | Loose poured state |
| Specific Surface Area (BET) | 15‑30 m² g⁻¹ | N₂ adsorption at 77 K |
| Median Particle Size (D₅₀) | 5‑15 µm | Laser diffraction, dry dispersion |
| pH (10 % slurry) | 7‑9 | Water at 25 °C |
| Moisture Content | ≤0.5 % | After 105 °C drying, 2 h |
Quality Control Philosophy
Each production lot undergoes systematic verification to ensure conformity with the specification table. Chemical composition is confirmed by inductively coupled plasma optical emission spectroscopy (ICP‑OES) on digested samples, providing elemental accuracy within ±0.2 %.
Particle size distribution is assessed using laser diffraction with a dry‑feed dispersant, repeatable to ±1 µm for D₅₀. Loss on ignition is measured by thermogravimetric analysis at 1000 °C to validate the amorphous nature and low organic load. All tests follow ISO/IEC 17025 accredited procedures, and results are retained for traceability.
Packaging Options
- 25 kg multiwall paper bags with polyethylene inner liner, palletized 40 bags per pallet.
- 500 kg flexible intermediate bulk containers (FIBC) with lift loops, suitable for pneumatic conveying.
- Bulk tanker truck or railcar delivery for continuous‑flow processes, equipped with moisture‑protective liners.
Frequently Asked Questions
Can the particle size be customized?
Yes, milling and classification adjustments can shift D₅₀ within the 2‑30 µm range to meet specific filtration or filler requirements. Custom grading is available upon request.
What information is needed for a quotation?
Please provide target SiO₂ purity, desired bulk density or particle size, order quantity, packaging preference, and delivery destination. This enables accurate cost and lead‑time estimation.
How is product quality verified before shipment?
Each batch receives a certificate of analysis (CoA) detailing chemical composition, particle size distribution, LOI, pH, and moisture content. Third‑party inspection can be arranged if required.
Request a Sample or Quote
To evaluate the suitability of amorphous silica diatomaceous earth powder for your process, contact our technical team. We can provide a representative sample and discuss specification tailoring to your application.