Smelting Process of Ferrosilicon Submerged Arc Furnace

author: Alice

2025-09-06

A ferrosilicon submerged arc furnace, also known as an submerged arc furnaces, smelting furnaces, or metallurgical furnaces, is an industrial device used to produce ferrosilicon alloys. It smelts silica, iron scrap, and reducing agents (such as coke) at high temperatures.

The ferrosilicon furnace process is crucial in the steel industry, as ferrosilicon alloys are used as deoxidizers and alloying agents.

The structure and operating parameters of the submerged arc furnace affect ferrosilicon production, quality, and energy consumption. Specifically, the furnace design must consider factors such as raw material ratios, temperature control, power consumption, and exhaust gas treatment.

Smelting Process of Ferrosilicon Submerged Arc Furnace

The ferrosilicon furnace smelting process primarily involves four steps: raw material preparation, batching and forming, smelting, and product post-processing.

First, raw materials such as silica, semi-coke, and iron oxide scale are ground and mixed in appropriate proportions to form billets.

The billets are then fed into the submerged arc furnaces, where they undergo high-temperature smelting under the action of an electric arc. Ferrosilicon production is achieved by controlling the reactants and power.

Finally, the slag is processed, the molten iron is removed, and preliminary cooling and inspection are performed, completing the entire production process.

1. Raw Material Preparation & Batching

Raw Material Processing

The main raw materials, such as silica, semi-coke (coke), and iron oxide scale, are ground into fine powders, typically with a particle size of less than 0.063mm.

Batch Mixing

The ground silica, semi-coke, iron oxide scale, and silicon micropowder are mixed at specific weight percentages.

Pressing & Molding

The mixed materials are pressed under pressure into billets. The size and shape of the billets depend on the furnace type. Before entering the furnace, they are dried to a moisture content of less than 3%.

2. Submerged Arc Furnaces Smelting Process

Charging

The dried billets are charged into the ferrosilicon submerged arc furnace in a specific order.

Arc Heating

When electricity is applied to the furnace, a strong arc is formed between the electrodes and the billet pile. The high temperature of the arc reduces the silica and carbon in the billet pile, causing a chemical reaction.

Chemical Reaction

Silica (SiO2) and carbon (C) react at high temperatures to produce silicon (Si) and carbon monoxide (CO). Simultaneously, the iron oxide in the iron oxide scale is reduced to produce iron (Fe).

Composition Control

By controlling parameters such as electrical power, electrode depth, and material ratio, the furnace temperature and reaction process are adjusted to achieve the desired ferrosilicon composition.

3. Product Post-Processing

Tapping & Slag

During the smelting process, molten ferrosilicon and slag are discharged from tapholes in the furnace bottom or walls.

Cooling & Inspection

The molten iron discharged from the submerged arc furnaces undergoes preliminary cooling and, as needed, undergoes composition analysis and quality inspection.

4. Key Elements and Optimization

Raw Material Quality

High-quality silica, semi-coke, and iron oxide scale are the foundation for producing high-grade ferrosilicon.

Energy Efficiency

Optimizing the raw material ratio and electrode control can improve energy efficiency and reduce energy consumption.

Environmental Benefits

Through rational process design and raw material handling, metallurgical furnaces can reduce pollution emissions and enhance social and economic benefits.

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