Ferro Silicon 72% (abbreviated as FeSi 72%) is a mid-range high-silicon ferroalloy with a silicon (Si) content of 72–74%, iron (Fe) as the balance (~24–26%), and strict impurity control. It fills the gap between lower-silicon FeSi 65% (cost-focused) and higher-silicon FeSi 75% (performance-focused), delivering optimal cost-effectiveness for applications requiring better deoxidation/alloying than FeSi 65% but without the premium cost of Ferro Silicon 75%. deoxidation efficiency is 15–20% higher than Ferro Silicon 65%, while cost is 8–12% lower than ferro silicon 75, making it the first choice for mid-scale high-quality steel/casting production.

Production Process

Raw Material Selection: Use high-purity silica (SiO₂ ≥97.8%, size 80–120mm) to ensure silicon yield; low-ash coke (fixed carbon ≥83%, sulfur ≤0.5%) as a reducer; and low-phosphorus iron scrap (P ≤0.03%) to control impurities.
Arc Furnace Smelting: Operate at 1750–1900℃, with real-time silicon content monitoring (via on-site spectral analysis). Adjust silica/coke ratio during smelting-adding 1–2% more silica than FeSi65 production to reach 72–74% Si, but 3–5% less than FeSi75 to avoid excess silicon loss.
Post-Smelting Treatment: Crush the alloy into lumps (10–50mm) or powder (50–200 Mesh), with magnetic separation to remove iron-rich impurities (Fe ≥95% purity) and screening to ensure particle size uniformity.

Ferro Silicon 72%

chemical composition

Parameter	Standard Range	Industrial Significance
Chemical Composition	Silicon (Si): 72–74%	Balances reactivity (better than FeSi 65%) and cost (lower than FeSi 75%); ideal for mid-grade steel.
	Iron (Fe): 24–26%	Ensures structural stability; avoids diluting silicon's deoxidation effect.
	Aluminum (Al): ≤1.8%	Aids casting inoculation (forms AlN nucleation sites) but controlled to prevent steel brittleness.
	Calcium (Ca): ≤0.6%	Reduces oxide inclusions; excessive Ca causes slag defects in thin-walled castings.
	Carbon (C): ≤0.18%	Prevents carburization in low-carbon steel (e.g., automotive DP steel, C ≤0.1%).
	Phosphorus (P): ≤0.035%	Avoids cold brittleness in weathering steel (e.g., Q355ND, used in bridges).
	Sulfur (S): ≤0.018%	Minimizes hot cracking in cast iron (e.g., ductile iron crankshafts).
Physical Forms & Sizes	Lumps: 10–50mm	Steel ladle addition (slow, uniform reaction; dust loss ≤8%).
	Granules: 3–10mm	Casting inoculation (even dispersion in molten iron; effective period ≥25 minutes).
	Powder: 50–200 Mesh	Magnesium smelting (fast dissolution) and welding rod production.
Physical Properties	Density: 3.05–3.2 g/cm³	Higher than FeSi 65% (2.9–3.0 g/cm³), ensuring full penetration in molten metal.
	Melting Point: ~1330℃	20–30℃ higher than FeSi 65% (1300℃), but lower than FeSi 75% (1350℃)-balances reaction speed.
	Moisture: ≤0.5%	Prevents hydrogen-induced porosity in high-pressure castings (e.g., hydraulic valves).

ferro silicon 72 Application

Deoxidizer:

During steelmaking, the silicon element in ferrosilicon 72 has a strong affinity with oxygen in molten steel and can react with it to remove oxygen, thereby reducing the oxygen content in molten steel, effectively reducing defects such as pores and inclusions in steel, improving the quality and performance of steel, making the organizational structure of steel more dense and uniform, and improving its mechanical properties.

Alloying agent:

Silicon can be added to molten steel to adjust the chemical composition of steel. The addition of silicon can improve the strength, hardness, elastic limit and other mechanical properties of steel, and can also improve the casting performance and welding performance of steel, etc., to meet the diverse performance requirements of different steel grades. It is widely used in the production of ordinary structural steel and some steel for machinery manufacturing.

Casting industry:

As an inoculant, ferrosilicon 72 can change the growth morphology and distribution of graphite in cast iron, prompting graphite to precipitate in a finer and more uniform state, thereby refining the grain structure of cast iron, improving the strength, toughness, wear resistance and other mechanical properties of cast iron parts, and making the cast products of higher quality. It is often used in the production of various cast iron parts such as automotive parts and mechanical accessories.

Ferroalloy production:

When producing other ferroalloys (such as silicon-manganese alloy, silicon-chromium alloy, etc.), ferrosilicon 72 can be used as a reducing agent. With its silicon element reducibility and its own low carbon content, it participates in the corresponding reduction reaction and helps synthesize other ferroalloy products.

Mineral processing industry:

The ground ferrosilicon powder (processed from ferrosilicon 72) can be used as a suspension phase in the mineral processing industry to assist in the sorting of minerals and other operations.

Welding rod manufacturing:

Ferrosilicon 72 can also be used as a component of welding rod flux core, which helps to improve the welding performance of welding rods, such as enhancing the strength of welds and improving the forming quality of welds, and plays an important role in the welding industry.

Ferro Silicon 72%

Core Advantages of Ferro Silicon 72% (vs. FeSi 65%/75%)

Performance Metric	Ferro Silicon 72%	Ferro Silicon 65%	Ferro Silicon 75%
Deoxidation Efficiency	88–92%	75–80%	93–95%
Silicon Utilization Rate	85–88%	80–83%	88–90%
Impurity Control	Moderate (Al ≤1.8%)	Lower (Al ≤2.5%)	Strict (Al ≤1.5%)
Ideal Application	Mid-grade steel/casting	Bulk steel/low-end casting	High-end steel/electrical steel