Fused silica price

When sourcing fused silica, the SiO2 purity level is the most critical factor, typically requiring 99.9% to 99.99% for high-end applications. You must verify the impurity concentrations (such as Fe, Al, Ca, and Mg) in PPM (parts per million), as these significantly affect thermal and optical performance. For optical grades, request data on hydroxyl (OH) content, which influences infrared transmission, and ensure the material is bubble-free and streak-free through ultrasonic or visual inspection reports.

The specifications vary by use case: for semiconductor manufacturing, focus on ultra-low thermal expansion coefficients and high chemical resistance. For investment casting, prioritize particle size distribution (mesh size) and refractoriness to ensure mold stability. If purchasing for optical lenses, specify the refractive index homogeneity and transmittance range (UV to IR). Always request a Certificate of Analysis (COA) to confirm the batch matches your specific technical requirements.

Price is heavily influenced by processing: fused silica lumps are generally cheaper, while fine powders (micronized) or spherical fused silica command a premium due to the additional grinding and flame-shaping processes. Spherical silica is particularly expensive because it offers better flowability and higher loading in electronic packaging. Ensure you specify the D50 and D90 particle size values to avoid paying for precision you may not need or receiving material that clogs your machinery.

Suppliers should ideally hold ISO 9001:2015 for quality management. For products exported to the EU, REACH compliance is essential to ensure the material does not contain restricted hazardous substances. Additionally, check for RoHS certification if the silica is used in electronic components. Since silica dust is a health hazard, verify that the supplier follows occupational health and safety standards during packaging to prevent leakage during transit.

Fused silica is highly sensitive to contamination. Insist on double-layered packaging, such as moisture-proof PE inner bags inside ton bags or plastic drums. For high-purity grades, specify vacuum sealing to prevent moisture absorption. On Made-in-China.com, look for Audited Suppliers who provide photos of the loading process to ensure the containers are clean and free from previous cargo residue.

Negotiate based on volume tiers and long-term forecasts. Since energy costs (electricity for electric arc furnaces) fluctuate, consider formula-based pricing linked to energy indices for long-term contracts. You can often achieve a 10-15% discount by increasing order volume to full container loads (FCL) to optimize logistics costs. Always request pre-shipment samples from the same production batch to lock in quality before final payment.

Use Secured Trading Services provided by platforms like Made-in-China.com to ensure payment is only released upon proof of shipment. For large bulk orders, utilize Third-Party Inspection (TPI) services like SGS or Intertek to conduct a Loading Check and Lab Testing at the port of departure. This prevents the 'bait and switch' risk where the sample differs from the bulk delivery.

Fused silica is heavy and dense; therefore, Ocean Freight is the most economical method. Ensure the supplier provides a detailed Packing List, Commercial Invoice, and Bill of Lading. Clarify the HS Code (typically 250620 or 281122) with your customs broker beforehand to determine accurate import duties and avoid delays. For urgent R&D needs, Air Freight is possible but requires specialized heavy-duty crating to prevent bag bursts.