Silicon Metal 331 – Premium Grade (Si ≥98.5%) for High-Performance Alloying & Chemical Industries
High-purity silicon metal with minimum 98.5% silicon content and tightly controlled impurities (Fe≤0.30%, Al≤0.30%, Ca≤0.10%). Ideal for demanding aluminum alloys, silicone synthesis, and specialty chemical applications.
| Main Composition | Si ≥98.5%, Fe ≤0.30%, Al ≤0.30%, Ca ≤0.10% |
| Form | Lumps (10-100mm), Granules (2-15mm), Powder (0-2mm, 0-10mm), Custom sizes available |
| Application | High-performance aluminum alloys (casting/extrusion), silicones & chemicals, photovoltaic (solar) industry, specialty refractories |
| Standard | GB/T 2881-2014, ASTM A922, ISO 8288 |
Silicon Metal 331 – Product Overview
Silicon Metal 331 is a premium grade of metallurgical silicon with a minimum silicon content of 98.5% and exceptionally low impurities (Fe ≤0.30%, Al ≤0.30%, Ca ≤0.10%). It is produced by carbothermic reduction of high-purity quartz in electric arc furnaces, followed by rigorous refining and quality control. Our Silicon Metal 331 offers an optimal balance of high purity and cost-effectiveness, making it the preferred choice for demanding applications where consistent chemistry and low impurity levels are critical.
Product Core Advantages
- High Purity: Minimum 98.5% Si with tightly controlled impurities (Fe, Al, Ca) for superior performance in sensitive applications.
- Excellent Consistency: Strict process control ensures uniform composition from batch to batch, critical for high-end alloying and chemical synthesis.
- Versatile Application: Ideal for premium aluminum alloys, silicone production, and chemical processes requiring low impurity levels.
- Custom Sizing: Available in lumps, granules, or powder to match your specific melting or reaction requirements.
- Stable Supply: Produced in modern submerged arc furnaces with ISO 9001:2015 certified quality management.
Typical Application Areas
Silicon Metal 331 is essential in high-performance industrial processes:
- Premium Aluminum Alloys: Added to molten aluminum to produce high-quality casting and extrusion alloys (e.g., 4xxx series) with improved mechanical properties and surface finish.
- Silicones & Specialty Chemicals: Primary raw material for the synthesis of high-purity silicones, silanes, and fumed silica where catalyst performance is critical.
- Photovoltaic (Solar) Industry: Used as a starting material for the production of solar-grade silicon, offering an ideal purity base for further refinement.
- Specialty Refractories: Used in the manufacture of high-temperature ceramics and advanced refractory materials.
- High-Grade Steel & Alloys: As a deoxidizer and alloying element in specialty steel grades requiring low impurity levels.
For specific application guidance or custom formulations, contact our technical team for personalized recommendations based on your production requirements.
Technical Specifications – Silicon Metal 331 & Common Grades
Our Silicon Metal 331 is produced to meet international standards with strict quality control. Below is the chemical composition of our primary grade (Si 331) compared with other common industrial grades for reference.
Chemical Composition (Typical Values, % by weight)
| Grade / Designation | Si (%) | Fe (%) | Al (%) | Ca (%) | Typical Application |
|---|---|---|---|---|---|
| Si 331 | ≥98.5 | ≤0.30 | ≤0.30 | ≤0.10 | High-purity aluminum alloys, chemical, silicones |
| Si 97 | ≥97.0 | ≤1.5 | ≤1.2 | ≤0.3 | General aluminum alloys, silicones, cost-sensitive |
| Si 441 (Grade 441) | ≥99.0 | ≤0.40 | ≤0.40 | ≤0.10 | Standard grade for aluminum, silicones |
| Si 553 (Grade 553) | ≥98.5 | ≤0.50 | ≤0.50 | ≤0.30 | General metallurgical, cost-sensitive |
| Si 1101 (Grade 1101) | ≥99.7 | ≤0.10 | ≤0.10 | ≤0.01 | Electronics, solar, ultra-pure applications |
Physical Properties
| Property | Value | Unit |
|---|---|---|
| Melting Point | 1410-1450 | °C |
| Density (at 20°C) | 2.33 | g/cm³ |
| Appearance | Silvery-gray metallic lumps / granules | - |
| Bulk Density (lumps) | 1.2-1.5 | g/cm³ |
Available Sizes
- Lumps: 10-80mm,10-100mm(standard), custom sizes available
- Granules: 2-15mm, 1-6mm
- Powder: 0-2mm, 0-10mm, -100 mesh, -200 mesh
- Custom Sizes: Available upon request to meet specific process requirements
Application Guidelines – Silicon Metal 331
Silicon Metal 331 is a versatile high-purity material with the following primary applications:
Premium Aluminum Alloying
Added to molten aluminum (typically at 5-12% for casting alloys) to improve fluidity, reduce hot tearing, and increase strength. The low impurity levels of Si 331 ensure superior quality in high-performance alloys, such as those used in automotive and aerospace components. Common in 4xxx series alloys (e.g., 4043, 4047) for welding wire and brazing sheets where consistent chemistry is essential.
Chemical Industry (Silicones)
Ground to fine powder and reacted with methyl chloride in the "direct process" to produce methylchlorosilanes, the precursors to silicone polymers. The tight control of Fe, Al, and Ca impurities in Si 331 is critical for optimal catalyst performance and high reaction yield, making it a preferred grade for silicone manufacturers.
Specialty Refractory & Ceramics
Used in the production of high-purity silicon nitride (Si₃N₄) and other advanced ceramics, as well as a raw material for premium silicon-based refractory products.
Photovoltaic (Solar) Applications
With its higher purity base (≥98.5% Si), Si 331 serves as an excellent starting material for solar-grade polysilicon production, reducing the refining burden in downstream processes.
Typical Addition Rates (Aluminum)
In aluminum alloying, addition rates typically range from 2% to 12% depending on the target alloy specification. Our technical team can assist with optimal sizing and addition practices for maximum recovery.
Packaging & Logistics – Silicon Metal 331
Packaging Options
We offer various packaging solutions to meet different customer requirements and ensure product integrity during transportation:
- 1‑ton Jumbo Bags: Common option, easy to handle with standard equipment.
- 25kg / 50kg Bags: For smaller orders or specific application requirements (e.g., foundries, R&D).
- Custom Packaging: We can accommodate special packaging requests, including moisture-proof liners, sealed drums, or small containers for sensitive applications.
Logistics Information
| Parameter | Details |
|---|---|
| Minimum Order Quantity | 20 metric tons (less for trial orders, subject to availability) |
| Lead Time | 15-20 days after order confirmation |
| Port of Loading | Main Chinese ports (Tianjin, Shanghai, Qingdao, Huangpu) |
| Shipping Options | FOB, CIF, CFR, DAP (depending on destination) |
| Payment Terms | T/T, L/C at sight, or negotiable |
Download Center
Access our technical documentation for detailed product information:
Frequently Asked Questions – Silicon Metal 331
Is it possible to entrust a third-party inspection to check the quality before shipment?
+
Certainly, we support third-party inspections by internationally recognized quality inspection agencies such as SGS and BV to verify product quality before shipment. The inspection covers product appearance, weighing, dimensions, and chemical composition analysis. The entire inspection process will be documented with photos and written records, which will be provided to you together with the final inspection report. This ensures you have no concerns regarding product quality.
What makes Silicon Metal 331 different from standard grades like 441 or 553?
+
Silicon Metal 331 offers a specific combination of low impurities: Fe ≤0.30%, Al ≤0.30%, and Ca ≤0.10%, with Si ≥98.5%. Compared to 441 (Fe≤0.40%, Al≤0.40%, Ca≤0.10%) and 553 (Fe≤0.50%, Al≤0.50%, Ca≤0.30%), Si 331 provides lower iron and aluminum levels, making it ideal for applications requiring higher purity, such as premium aluminum alloys and sensitive chemical processes.
Is Silicon Metal 331 suitable for silicone production?
+
Yes, Si 331 is an excellent choice for silicone production. Its controlled low levels of Fe, Al, and Ca are critical for maintaining catalyst activity and achieving high yields in the direct synthesis of methylchlorosilanes. It is often preferred over lower purity grades for consistent process performance.
What sizes are recommended for aluminum alloying with Si 331?
+
For aluminum melting, lumps in the range of 10-100mm are typical to ensure easy immersion and good recovery. Smaller granules (2-15mm) can also be used for rapid dissolution in mechanically stirred furnaces or for precise alloying. We can supply custom sizes based on your specific process requirements.
Do you provide a certificate of analysis with each shipment of Si 331?
+
Absolutely. Every batch of Silicon Metal 331 is tested in our ISO 17025 accredited laboratory, and a Certificate of Analysis (COA) showing Si, Fe, Al, Ca, and other relevant elements is provided with the shipping documents. We maintain full traceability.
What is your production capacity for Silicon Metal 331?
+
We have an annual production capacity exceeding 50,000 metric tons of silicon metal across various grades, including Si 331, 441, 553, and 1101. We can accommodate both containerized and bulk vessel shipments, with dedicated production lines for high-purity grades.
Why Choose Our Silicon Metal
20+ Years Experience
Specialized in ferroalloy production with deep industry knowledge
Strict Quality Control
Every batch tested to ensure consistent composition and performance
Global Delivery
Reliable logistics network ensuring timely delivery worldwide
Quality & Production Showcase
Explore our quality control process, production facilities, and customer interactions
Silicon Metal Different Grades Comparison
Loading product overview...
Related Products
High Purity Ferro Silicon
Ultra-Low Impurity FeSi Si 76-79%, Al ≤0.01%, Ca ≤0.05%, C ≤0.015%, B ≤0.002%, Ti ≤0.02%, P ≤0.02%, S ≤0.005% Lumps (10-100mm)
View DetailsReady to Order or Need More Information?
Contact our technical sales team for pricing, samples, or application advice tailored to your specific needs.
Contact Us Today