How Ferrosilicon Is Made: Raw Materials, Smelting and Price Drivers

Raw Materials: Silica and Coke

The production of ferrosilicon relies mainly on two raw materials: silica and coke. Silica, usually in the form of quartz or quartzite, must be high in SiO2 and low in alumina and phosphorus. Coke and other carbon materials such as charcoal or coal serve as the reductant; their ash content and reactivity affect both the process and the impurity level of the alloy. The raw materials are crushed and screened to a controlled size range so that the furnace charge is consistent and permeable.

Smelting in the Submerged-Arc Furnace

The prepared silica and coke are mixed in a certain proportion and charged continuously into a large submerged-arc electric furnace. Under the action of the high-temperature electric arc, silicon dioxide in the silica reacts with carbon in the coke to generate silicon and carbon monoxide gas. The overall reaction is approximately SiO2 + 2C = Si + 2CO. Iron sources such as steel scrap or iron ore are added to form the iron-silicon alloy and to control the silicon content of the product. Temperature, power input and the raw material ratio must be strictly controlled to achieve the target silicon purity and a good yield.

Tapping, Cooling and Sizing

The generated ferrosilicon liquid is discharged through the iron outlet and cast into blocks or granulated, depending on the plant. After cooling, the alloy is crushed and screened into the standard lump sizes, typically 0-3 mm, 3-10 mm, 10-50 mm or 10-100 mm, and fines are recycled or sold separately. The entire production process requires efficient equipment and precise operation control to ensure consistent product quality and production efficiency.

Key Factors Affecting Ferrosilicon Prices

Electricity cost: the largest cost component, since ferrosilicon smelting is highly energy-intensive.

Raw material costs: silica, coke and iron source prices, including logistics to the plant.

Supply and demand: steel and foundry production schedules drive consumption, while regional capacity and curtailment affect supply.

Exchange rates and trade policy: currency movements and tariffs change the effective export price.

Transportation cost: distance from production regions in China to the destination port or buyer.

Buying Notes

Confirm the silicon content range (for example FeSi65, FeSi72 or FeSi75) and impurity limits on the COA.

Agree on lump size and packing to match your charging equipment.

Compare quotes on the same Incoterm and payment terms, and consider energy price trends when timing purchases.

For consistent steel chemistry, choose a supplier with stable raw material sourcing and batch traceability.

FAQ

1. What are the main raw materials for ferrosilicon?

Silica (quartz) and carbon reductants such as coke, together with an iron source such as steel scrap; the purity of each directly affects the grade of the finished alloy.

2. Why is ferrosilicon smelting so energy-intensive?

The reduction of silicon dioxide by carbon requires very high temperatures and a continuous electric arc, so electricity typically accounts for more than a third of the production cost, and plants are usually located near low-cost power.

3. What determines the silicon content of the alloy?

The ratio of silica to reductant and iron source, the purity of the raw materials, and the furnace temperature profile all determine the final silicon content, which is why the charge ratio is controlled precisely.

4. How is the molten ferrosilicon handled after tapping?

It is cast into molds or granulated, cooled, then crushed and screened into the required lump sizes; oversized pieces are recrushed and fines are recycled or sold for other uses.

5. Why do ferrosilicon prices vary between regions?

Electricity prices, raw material availability, transport distances and regional supply-demand balances differ, so the same grade can trade at different levels in different markets.