Silicon 441, also known as industrial silicon 441 or Si441, is a high-purity metallurgical-grade silicon product. Its core definition stems from its strict control over impurity content. The numbers 441 directly correspond to the maximum permissible content of the three main impurities (iron, aluminum, and calcium) in the product. It is an internationally recognized standard for grading silicon and one of the most commonly specified mainstream grades in industrial procurement.
Core Components of Silicon 441
|
Element |
Silicon (Si) |
|
Minimum/Maximum Content |
≥ 99.0% |
|
Typical Actual Content |
99.1% - 99.3% |
|
Element |
Iron (Fe) |
|
Minimum/Maximum Content |
≤ 0.4% |
|
Typical Actual Content |
0.3% - 0.4% |
|
Element |
Aluminum (Al) |
|
Minimum/Maximum Content |
≤ 0.4% |
|
Typical Actual Content |
0.3% - 0.4% |
|
Element |
Calcium (Ca) |
|
Minimum/Maximum Content |
≤ 0.1% |
|
Typical Actual Content |
0.05% - 0.1% |
Physicochemical Properties of Silicon 441
Appearance: Silver-gray with a metallic luster; hard and brittle; smooth fracture surface free of impurities.
Melting Point: Approximately 1414℃; extremely high thermal stability, suitable for high-temperature smelting environments.
Density: Approximately 2.33 g/cm³; lightweight, easy to store and transport.
Conductivity: A semiconductor material, suitable as a base material for some electronic components.
Corrosion Resistance: Stable in air, water, and most acids at room temperature; not easily oxidized or deteriorated.
Applications of Metallic Silicon 441
Steel Smelting: As a high-quality deoxidizer and alloying element, it is used in the production of ordinary carbon steel and low-alloy steel. Its low reaction free energy with oxygen allows it to preferentially combine with oxygen in molten steel to form SiO₂, which is discharged with the slag, effectively reducing the oxygen content of the molten steel (from 80-100 ppm to 40-60 ppm). Simultaneously, it acts as a slag collector, promoting impurity settling, improving steel purity, and reducing defects such as porosity and inclusions. Furthermore, adding an appropriate amount of metallic silicon 441 can improve the strength, hardness, and toughness of steel, meeting the production needs of conventional steels such as those used in construction and machinery manufacturing.
Cast Iron Modification: Added as an inoculant to molten iron (0.2%-0.5% of the iron mass), it promotes graphitization precipitation, refines cast iron grains, and increases the impact toughness of gray cast iron by 20%-30%. This effectively improves the machinability and mechanical properties of cast iron, making it suitable for producing ordinary cast iron parts such as machine tool beds, pipes, and general machinery castings, reducing the risk of cracking and deformation.
Chemical Industry: With its low impurities (especially calcium ≤0.1%), metallic silicon 441 has become a core raw material for organosilicon synthesis. It avoids catalytic side reactions, ensures uniform molecular weight distribution of organosilicon polymers, and supports the production of high-value-added chemical products, making it an indispensable raw material in the chemical industry.
Other Chemical Fields: It can be used to produce silicides, molecular sieves, and other chemical products. Silicides are used for the modification of ceramics and glass, while molecular sieves are used for gas separation, adsorption drying, and other applications, meeting the needs of the petrochemical and environmental protection industries. Simultaneously, its powder can be used as an auxiliary catalyst in chemical reactions, improving reaction efficiency and product purity.
Casting Auxiliary Materials: As an inoculant and grain refiner in casting, it is added to the molten metal of various castings to improve the fluidity of the molten metal, reduce casting defects such as shrinkage cavities and porosity, and enhance the density and mechanical properties of castings, meeting the casting production needs of industries such as machinery and hardware.
Electronic Auxiliary Materials: Used in the production of housings and lead frames for common electronic components, its good conductivity and mechanical strength meet the production needs of low- to mid-range electronic devices. It can also be used as an auxiliary component in electronic packaging materials to improve the sealing and heat resistance of the packaging.
