Production of Silico-Manganese in a Submerged Arc Furnace

The production of silicon-manganese in a submerged arc furnace is a complex metallurgical process, which mainly obtains silicon-manganese alloy (usually Si-Mn, such as SiMn65-17) by reducing and smelting manganese ore and silica oxides such as manganese, iron, and silicon.

The following are the key steps and technical points of silicon-manganese alloy submerged arc furnaces smelting, let us discuss together

1) Raw Material Preparation of Silicon-manganese Furnace

• Manganese ore: The main source is manganese oxide ore (such as pyrolusite MnO₂, brown manganese ore Mn₂O₃), requiring manganese content ≥30% and low impurities (phosphorus, sulfur).

• Silica (SiO₂): Provides silicon source, requiring SiO₂≥97%, and particle size 10 - 60mm.

• Reducing agent: coke or anthracite (fixed carbon ≥80%), which is both a reducing agent and a heat source.

• Flux: lime (CaO) or dolomite, used to adjust the basicity of SAF slag (CaO/SiO₂≈0.60.8) and reduce the melting point.

2) Production of Silico-Manganese in a Submerged Arc Furnace Smelting Principle

High temperature reduction reaction (furnace temperature 13001600℃):

• Manganese oxide reduction:

MnO 2 → Mn2O3 → Mn3O4 → MnO →Mn

• Silica reduction:

SiO2 + 2C → Si + 2CO SiO2 + 2C → Si + 2CO

Iron oxide is reduced to iron and forms an alloy with manganese and silicon.

SAF Final Product

Silicon manganese alloy (typical composition: Mn 65 - 68%, Si 17 - 20%, C 1.52%, Fe balance).

Slag (main component is CaOSiO₂Al₂O₃), manganese content needs to be controlled (<5% to reduce losses).

3) Silicon-manganese alloy submerged arc furnace process flow

1. Batching & mixing

Mix according to the ratio of manganese ore, silica, coke and flux (such as manganese ore: silica ≈ 1:0.20.3).

The raw materials need to be dried and crushed to the appropriate particle size (coke 10 - 25mm, ore 10 - 50mm).

2. Charging & smelting

The mixed material is added to the closed or semi-closed submerged arc furnace (usually 10 - 50MW power) from the top of the SAF furnace.

The electrodes generate arc heat, the coke combustion provides a reducing atmosphere, and the furnace is layered (upper pre-reduction, lower melting zone).

3. Iron tapping & casting

The alloy liquid and slag are regularly discharged from the furnace eye of the Silicon manganese furnace (once every 24 hours).

The alloy liquid is cast into ingots or granulated, and the slag can be used for building materials after water quenching.

4. Flue gas treatment

Recover coal gas (CO content 60 - 70%) for power generation or heating.

Dust removal (bag or electrostatic precipitator) reduces dust emissions.

4) Key Control Parameters of Silicon Manganese Furnace

• Power consumption: 3500 - 4500 kWh/ton alloy (accounting for more than 60% of the cost).

• Electrode management: self-baking electrodes need to control the sintering speed to avoid breakage.

• Slag basicity: affects manganese recovery rate (usually 85 - 90%).

• Temperature control: too high increases silicon content, too low leads to insufficient manganese reduction.

5) Product Application

Silicon manganese alloy is mainly used for:

• Steelmaking deoxidizer (replace pure silicon and pure manganese, reduce costs).

• Alloy additive (improve steel strength and wear resistance).

• Raw materials for producing low-carbon ferromanganese or metallic manganese.

6) Environmental Protection & Energy Saving

• Waste heat utilization: recover coal gas for power generation.

• Dust recovery: manganese-rich dust returns to smelting.

• Low-carbon direction: explore hydrogen reduction or biomass reduction technology.

The above is about the production of silicon-manganese in a submerged arc furnace. Regarding the silicon manganese alloy submerged arc furnaces, if you need more detailed parameters (such as specific formula, furnace design) or encounter production problems (such as furnace condition fluctuations, excessive energy consumption), please feel free to contact us for further discussion.