Ferro Silicon 70% (abbreviated as FeSi 70) is a critical ferroalloy with a guaranteed silicon (Si) content of 70±2% and iron (Fe) as the balance (28–29%), plus strict impurity control (C≤0.5%, Al≤2.0%, S≤0.05%, P≤0.05%). Unlike lower-silicon grades (e.g., FeSi 50) with weaker deoxidation capacity or higher-silicon FeSi 90 (with premium costs), FeSi 70 strikes an optimal balance: strong deoxidation efficiency (silicon's affinity for oxygen is 3x higher than manganese) and cost-effectiveness (20–30% cheaper than FeSi 90). Available in lumps (10–50mm) or granules (1–3mm), it is indispensable for steelmaking, casting, and alloy production, solving the pain points of incomplete deoxidation and high raw material costs.

FeSi 70 is produced by smelting silica (SiO₂) and coke with iron scrap in electric arc furnaces, forming a master alloy that simplifies silicon addition to molten metals. Its unique value for metallurgy lies in three critical traits:

High Deoxidation Efficiency: 70% silicon content enables rapid reaction with dissolved oxygen (O) in molten steel (Si + O₂ → SiO₂), reducing O to ≤30ppm (vs. ≤50ppm with FeSi 50) and eliminating oxide inclusions (e.g., FeO) that cause casting defects.
Cost-Effective Alloying: Balances silicon content and price-70% Si provides 90% of FeSi 90's deoxidation capacity at 70–80% of the cost, ideal for high-volume steel production (e.g., construction steel, automotive sheet steel).
Dual-Function Performance: Acts as both a deoxidizer and alloying agent-silicon enhances steel's strength and corrosion resistance, while iron ensures compatibility with base metal compositions (no dilution issues).

These traits make 70# Ferro Silicon the most widely used high-silicon ferroalloy for medium-to-large-scale metallurgical processes, bridging the gap between low-silicon cost and high-silicon performance.

Ferro Silicon 70

chemical composition

Parameter	Standard Range	Metallurgical Significance
Main Components	Si: 68–72%, Fe: 28–29%	70% Si ensures rapid deoxidation-reduces addition volume by 30% vs. FeSi 50 (for same O removal).
Key Impurities (Max.)	C≤0.5%, Al≤2.0%	C≤0.5% avoids carburization in low-carbon steel (e.g., IF steel); Al≤2.0% prevents brittle AlN inclusions in low-temperature applications.
Key Impurities (Max.)	S≤0.05%, P≤0.05%	S≤0.05% reduces hot cracking in cast steel; P≤0.05% avoids cold brittleness in structural steel (Q355).
Physical Form	Lumps: 5–50mm; Granules: 1–3mm	Lumps for bulk steel ladles; granules for precision casting (uniform dissolution).
Deoxidation Efficiency	O Reduction Rate: 75–85%	Reduces molten steel O from 80–100ppm to ≤30ppm-meets high-quality steel requirements (O≤40ppm).

Usage and characteristics

Usage:

Ferro silicon 70 is mainly used in the iron and steel metallurgical industry as a deoxidizer and alloy additive. It can effectively remove oxygen and other impurities from steel and improve the quality and performance of steel. In addition, FeSi 70 is also used in the manufacture of some special steels or cast iron.

Characteristics:

Ferro silicon 70 has good thermal stability and chemical stability, and can exist stably in high temperature environments. Its addition can significantly improve the steel smelting process and the mechanical properties of the final product, especially the hardness and wear resistance.

Although ferrosilicon is a common alloy material, it reacts when in contact with oxygen, so appropriate safety measures need to be taken during storage and transportation. In some cases, ferrosilicon can also cause dangerous combustion and explosion phenomena, so its usage and production process need to be strictly controlled during industrial production and use.

Ferro Silicon 70

Sourcing Guide: How to Select Ferro Silicon 70%

To maximize the value of FeSi 70 for your process, follow these critical criteria:

Verify Purity & Impurities:

Ensure Si=68–72% (request third-party SGS/BV test reports)-avoid "low-grade FeSi 70" with actual Si≤65%.
For low-carbon steel: Prioritize C≤0.3% to avoid carburization (C≤0.2% for IF steel).
For stainless steel: Al≤1.5% to prevent AlN inclusions that reduce corrosion resistance.

Select Physical Form by Process:

Bulk steelmaking (EAF/AOD): 10–50mm lumps (stable feeding, low dust loss).
Precision casting (small batches): 1–3mm granules (fast dissolution, precise dosing).
Continuous casting: 5–20mm lumps (uniform alloying, no segregation).

Our Ferro Silicon 70% Solutions

As a professional ferroalloy supplier with 15+ years of metallurgical experience, we offer:

High-Quality FeSi 70: Guaranteed Si=68–72%, with two tailored variants:
Steel Grade: C≤0.3%, Al≤1.5%, optimized for carbon/low-alloy steel.
Casting Grade: C≤0.5%, Al≤2.0%, ideal for gray/ductile iron.
Custom Forms & Sizes: 1–3mm granules (25kg vacuum bags) or 10–50mm lumps (1000kg jumbo bags)-adapt to your feeding equipment.

Contact us today to request a free 1kg sample and customized quote-optimize your deoxidation efficiency and reduce costs with Ferro Silicon 70%!

Hot Tags: ferro silicon 70, China ferro silicon 70 manufacturers, suppliers, factory, Ferro Silicon, Ferro Silicon 72, Ferro Silicon 75, Ferro Silicon Alloy, Ferro Silicon Powder, Low Carbon Ferro Silicon