Why Source Silicon Metal from Us - Value Proposition from Process to Delivery
High Purity Raw Materials
Produced from carefully selected quartz and low-ash reducing agents to ensure consistent quality and low impurity levels.
- Feedstock Traceability & Reductant Blending. Our quartz feed comes from fixed mining sources in Inner Mongolia and Xinjiang, with SiO₂ content controlled within ±0.5% variability. Reducing agents are formulated using low-ash petroleum coke and bituminous coal at optimized ratios to prevent resistivity drift in the furnace burden. The carbon stoichiometry is adjusted based on real-time furnace conditions, minimizing the carryover of metallic impurities (Fe, Al, Ca) from raw materials into the final product.
- Tapping & Casting Practice. Tapping temperature is maintained at 1450–1500°C using ladle casting into metal molds. Controlled cooling rates produce dense ingot structures with a thin surface oxide layer (≤0.5 mm). Subsequent crushing employs a jaw crusher followed by a cone crusher in two-stage closed-loop configuration, with magnetic drum separators installed downstream to remove tramp iron introduced during size reduction-ensuring iron content consistently stays below the grade specification limits.
- Particle Size Distribution & Screening Precision. Standard lump product (10–100 mm) is classified using triple-deck vibrating screens with regularly calibrated mesh sizes. Typical screening performance yields <8% undersize (<10 mm) and <5% oversize (>100 mm). For customers with specific furnace feed requirements, narrow-range size fractions (e.g., 20–50 mm, 30–80 mm) are available upon request.
- Quality Assurance & Traceability. Two samples are collected per shift-one at the tapping spout and one from the finished product stream. In-house laboratories are equipped with ICP-OES for Fe, Al, Ca, and other elemental analysis; carbon/sulfur analyzers for carbon content; and oxygen/nitrogen/hydrogen determinators for gas content. Each batch is issued with a comprehensive Certificate of Analysis (COA), and retained samples are archived for at least six months to enable full traceability from furnace heat number to customer lot.
- Export Compliance & Logistics Capability. We maintain a complete dossier of export documentation, including Dangerous Goods Transport Certificates, MSDS, and shipping declarations. With established partnerships with multiple freight forwarders and shipping lines, we operate under CIF, FOB (predominantly Qingdao Port and Tianjin Port), and other trade terms. The East Asia route (South Korea, Japan) benefits from frequent sailings, while Southeast Asian and Middle Eastern destinations have stable container slot allocations.
Request current silicon metal price or a 1–2 kg free sample? English MSDS and COA samples are available upon request. Factory inspections-including furnace-side lab and finished goods warehouse-are welcome by appointment.
Silicon Metal Specifications
Chemical Composition
| Grade | Si (%) | Fe (%) | Al (%) | Ca (%) |
|---|---|---|---|---|
| 553 | ≥98.5 | ≤0.50 | ≤0.50 | ≤0.30 |
| 441 | ≥99.0 | ≤0.40 | ≤0.40 | ≤0.10 |
| 421 | ≥99.0 | ≤0.40 | ≤0.20 | ≤0.10 |
| 411 | ≥99.0 | ≤0.40 | ≤0.10 | ≤0.10 |
| 3303 | ≥99.3 | ≤0.30 | ≤0.30 | ≤0.03 |
| 2202 | ≥99.5 | ≤0.20 | ≤0.20 | ≤0.02 |
Impurity limits listed are maximum allowable values; actual typical batch values generally run 10–20% below these limits. Standard lump size: 10–100 mm (≥90%). Custom sizes available: 3–10 mm, 1–5 mm, 0–3 mm, 5–30 mm, 30–80 mm.
Product Forms
Silicon Metal Lump
Widely used in aluminum alloy production and silicone manufacturing.
Silicon Metal Granules
Ideal for automated feeding systems and precise dosing applications.
Silicon Metal Powder
Suitable for chemical processing, powder metallurgy, and specialized industrial applications.
Key Application Areas & Technical Rationale
- Aluminum Alloy Melting (~45% of global consumption). In Al-Si casting alloys (e.g., A356, ADC12, ZL101), silicon acts as the primary alloying element, forming a eutectic structure that improves fluidity, tensile strength, and wear resistance. Addition rates typically range from 7% to 12% depending on target specifications. High-iron silicon metal promotes the precipitation of acicular iron phases in aluminum alloys, degrading ductility-which is why premium wheel alloys favor 3303 or 2202 grades with tighter iron control.
- Silicone Monomer Synthesis (Chemical-Grade Application). In the Rochow direct synthesis process, silicon metal reacts with methyl chloride over a copper-based catalyst to produce methylchlorosilane monomers. This reaction is highly sensitive to impurity levels-elevated calcium deactivates the catalyst, high aluminum affects reaction selectivity, while iron levels influence activation temperature. Chemical-grade silicon (typically 411 or 3303) is therefore specified with stricter impurity limits, and often requires higher crystal activity.
- Polysilicon Feedstock (Photovoltaic & Semiconductor Supply Chain). Through the trichlorosilane hydrogen reduction route (modified Siemens process) or silane fluidized-bed process, metallurgical-grade silicon is refined to electronic-grade polysilicon (purity > 99.9999999%). This upstream application increasingly imposes implicit limits on boron (≤15 ppm) and phosphorus (≤20 ppm), a specification that some polysilicon producers now include in their purchasing requirements.
- Steelmaking Deoxidation & Alloy Addition. In electric arc or basic oxygen steelmaking, silicon metal serves as an effective deoxidizer: Si + O₂ → SiO₂. The resulting silica rises into the slag phase, reducing dissolved oxygen in molten steel and preventing blowhole formation and inclusion defects in continuous casting. Silicon also provides solid-solution strengthening of ferrite, enhancing elastic limit and hardenability-critical in electrical steel (silicon steel sheets) and spring steel production.
- Refractories & Ceramics. Ground to fine powder (typically –200 mesh), silicon metal is incorporated into alumina-carbon bricks, magnesia-carbon bricks, and silicon carbide-based refractories as an oxidation inhibitor. At elevated service temperatures, silicon metal oxidizes preferentially, forming a glassy phase that seals surface pores and retards carbon oxidation-extending furnace lining life. This segment accepts 553 or 97-grade material, with key parameters being particle fineness and oxidation activity.
General Inquiries
Q1: What furnace types do you operate, and what is your capacity?
We operate four submerged arc furnaces rated at 12500 KVA and 16500 KVA, with a combined monthly output of approximately 3000 MT. Long-term framework contracts exceeding 500 MT are acceptable.
Q2: How do you ensure batch-to-batch composition consistency?
We implement a three-point sampling protocol per heat (early, mid, late tapping stages), with composite analysis guiding adjustments to carbon balance and burden ratios for subsequent heats. Feedstock sources undergo full re-assay every six months, with advance notice provided to long-term customers if changes are anticipated.
Q3: What is the typical yield for 1–5 mm granular product?
Using roll-crushers in closed circuit with screening, the yield in the 1–5 mm fraction typically ranges from 75% to 80%. Oversize material can be returned to the circuit or sold as a by-product at negotiated terms.
Q4: Can you arrange third-party inspection (SGS or BV)?
Yes. SGS, BV, or CCIC inspection at the loading port can be arranged prior to shipment, with costs to be discussed based on the specific testing scope. Routine parameters (Si, Fe, Al, Ca) typically require 3–5 working days for reporting.
Q5: What is your price quote validity period?
Given frequent fluctuations in electrode paste, petroleum coke, and electricity costs, our standard quotation is valid for 3 working days. Annual contracts may adopt quarterly or monthly index-linked price adjustments-terms are negotiable.
Q6: Do you have a minimum order quantity?
The standard MOQ is 25 MT (one full container or truckload). For new customers, we can arrange 1–2 MT trial orders, though freight costs are to be borne by the buyer.
Hot Tags: Silicon Metal Industrial Silicon, China Silicon Metal Industrial Silicon manufacturers, suppliers