Silicon Metal 553 – Standard Grade (Si ≥98.5%) for Alloying & Metallurgical Industries
Cost-effective silicon metal with minimum 98.5% silicon content, balanced impurities (Fe ≤0.5%, Al ≤0.5%, Ca ≤0.3%). Widely used in aluminum alloying, silicone synthesis, and high-temperature refractories.
| Main Composition | Si ≥98.5%, Fe ≤0.5%, Al ≤0.5%, Ca ≤0.3% (typical impurities) |
| Form | Lumps (10-100mm), Granules (2-15mm), Powder (0-2mm, 0-10mm), Custom sizes available |
| Application | Aluminum alloying (casting/extrusion), silicones & chemicals, photovoltaic (solar) industry, refractory materials |
| Standard | GB/T 2881-2014, ASTM A922, ISO 8288 |
Silicon Metal 553 – Product Overview
Silicon Metal 553 is a standard metallurgical-grade silicon with a minimum silicon content of 98.5%. It is produced by carbothermic reduction of quartz in electric arc furnaces. Our Silicon Metal 553 offers a well-balanced impurity profile (Fe ≤0.5%, Al ≤0.5%, Ca ≤0.3%) making it a cost-effective choice for a wide range of applications, from aluminum alloying to chemical synthesis. It serves as a fundamental building block for silicone polymers and as an alloying element to improve the mechanical properties of aluminum.
Product Core Advantages
- Reliable Purity: Minimum 98.5% Si with controlled impurities (Fe, Al, Ca) for consistent performance in general applications.
- Versatile Application: Equally suitable for aluminum alloying (casting and extrusion), silicone production, and refractory industries.
- Custom Sizing: Available in lumps, granules, or powder to match your specific melting or reaction requirements.
- Cost-Effective: Excellent balance of purity and price for applications where ultra-high purity is not required.
- Stable Supply: Produced in modern submerged arc furnaces with strict quality control from raw material to finished product.
Typical Application Areas
Silicon Metal 553 is essential in many industrial processes:
- Aluminum Alloying: Added to molten aluminum to improve fluidity, reduce cracking, and enhance mechanical properties in castings and extrusions (e.g., 4xxx series alloys).
- Silicones & Chemicals: Primary raw material for the synthesis of silicones, silanes, and fumed silica.
- Photovoltaic (Solar) Industry: Used as a starting material for the production of solar-grade silicon after further purification.
- Refractory Materials: Used in the manufacture of high-temperature ceramics and refractory bricks.
- Stainless & Specialty Steels: As a deoxidizer and alloying element in certain steel grades.
For specific application guidance or custom formulations, contact our technical team for personalized recommendations based on your production requirements.
Technical Specifications – Silicon Metal 553 & Common Grades
Our Silicon Metal 553 is produced to meet international standards with strict quality control. Below is the chemical composition of our primary grade (Si 553) compared with other common industrial grades for reference.
Chemical Composition (Typical Values, % by weight)
| Grade / Designation | Si (%) | Fe (%) | Al (%) | Ca (%) | Typical Application |
|---|---|---|---|---|---|
| Si 553 | ≥98.5 | ≤0.50 | ≤0.50 | ≤0.30 | General metallurgical, cost-sensitive applications |
| Si 97 | ≥97.0 | ≤1.5 | ≤1.2 | ≤0.3 | Aluminum alloys, general use |
| Si 331 | ≥98.5 | ≤0.30 | ≤0.30 | ≤0.10 | High-purity aluminum alloys, chemical |
| Si 441 | ≥99.0 | ≤0.40 | ≤0.40 | ≤0.10 | Standard grade for aluminum, silicones |
| Si 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 553
Silicon Metal 553 is a versatile material with the following primary applications:
Aluminum Alloying
Added to molten aluminum (typically at 5-12% for casting alloys) to improve fluidity, reduce hot tearing, and increase strength. Common in 4xxx series alloys (e.g., 4043, 4047) for welding wire and brazing sheets. Our Si 553 provides consistent chemistry for predictable alloy properties.
Chemical Industry (Silicones)
Ground to fine powder and reacted with methyl chloride in the "direct process" to produce methylchlorosilanes, the precursors to silicone polymers. Controlled impurity levels (especially Fe, Al, Ca) are critical for catalyst performance and reaction yield.
Refractory & Ceramics
Used in the production of silicon nitride (Si₃N₄) and other advanced ceramics, as well as a raw material for silicon-based refractory products.
Photovoltaic (Solar) Applications
After further purification (e.g., via the Siemens process), metallurgical-grade silicon (like Si 553) serves as the starting material for solar-grade polysilicon.
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.
Packaging & Logistics – Silicon Metal 553
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).
- Custom Packaging: We can accommodate special packaging requests, including moisture-proof liners or small drums.
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 553
Is it possible to entrust a third-party inspection to check the quality before shipment?
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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 is the difference between Silicon Metal 553 and higher purity grades like 441 or 1101?
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Silicon Metal 553 has a minimum Si content of 98.5%, with impurities Fe ≤0.5%, Al ≤0.5%, Ca ≤0.3%. Grades like 441 (Si≥99.0%, Fe≤0.4%, Al≤0.4%, Ca≤0.1%) have tighter impurity controls, while 1101 (Si≥99.7%) is ultra-pure. Si 553 is a cost-effective choice for applications where moderate impurity levels are acceptable, such as many aluminum alloys and general chemical use.
Can Silicon Metal 553 be used for silicone production?
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Yes, Si 553 is commonly used as a starting material for silicones. While higher purity grades (e.g., 441) are often preferred for optimal catalyst efficiency, Si 553 can be suitable for certain silicone applications where impurity tolerance is higher, or as a blend stock. We recommend discussing your specific process with our technical team.
What sizes are best for aluminum alloying?
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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. We can supply custom sizes based on your furnace type and charging practice.
Do you provide a certificate of analysis with each shipment?
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Absolutely. Every batch of Silicon Metal 553 is tested in our ISO 17025 accredited laboratory, and a Certificate of Analysis (COA) showing Si, Fe, Al, Ca, and other elements is provided with the shipping documents.
What is your production capacity for Silicon Metal 553?
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We have an annual production capacity exceeding 50,000 metric tons of silicon metal across various grades, including Si 97, 441, 553, and 1101. We can accommodate both containerized and bulk vessel shipments.
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
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Silicon Metal Different Grades Comparison
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