Process Characteristics of Vacuum Refining Furnace

author: Alice

2025-07-25

A vacuum refining furnace is a device used to refine molten steel. It includes a steel ladle and a liftable vacuum furnace cover, and is refined in a vacuum environment.
The vacuum furnace refining process is to move the primary molten steel to another reactor for refining, also known as secondary refining. Its purpose is to divide the traditional steelmaking method into two steps: primary refining and refining.

Process Characteristics of Vacuum Refining Furnace

There are two types of vacuum furnace refining processes:

Primary refining: melting, dephosphorization, decarburization and alloying of the charge in an oxidizing atmosphere.
Refining: deep decarburization, degassing, deoxidation, removal of inclusions and inclusion denaturation treatment under vacuum, inert gas or controlled atmosphere conditions, adjustment of composition, control of molten steel temperature, etc., so as to optimize the process and product structure, develop high value-added products, save energy and reduce consumption, reduce costs and increase economic benefits.

Refining Furnaces Process Flow

The ladle to be treated is hoisted by a crane onto the ladle trolley, which is driven to the treatment position below the vacuum tank. The height of the molten steel is manually determined, and then the ladle trolley is lifted to the predetermined height.

- Temperature measurement, sampling, oxygen determination and other operations are carried out.

- The ladle car is lifted again by the hydraulic cylinder, and the immersion pipe of the vacuum tank is immersed in the molten steel to a predetermined depth. At the same time, argon is blown into the rising immersion pipe at a predetermined flow rate. As the immersion pipe is completely immersed in the molten steel, the vacuum pump starts.

- Each level of vacuum pump works according to the pre-set exhaust curve.

- Vacuum dehydrogenation treatment: Continuous cyclic degassing operation is carried out under the specified time and specified low pressure conditions to achieve the target value of dehydrogenation.

- Vacuum decarburization treatment (low-carbon or ultra-low-carbon grade molten steel): Circulation degassing will continue for a certain period of time to achieve the target value of decarburization. During the decarburization process, carbon and oxygen in the molten steel react to form carbon monoxide and are discharged through the vacuum pump.
If the oxygen content in the steel is insufficient, oxygen can be provided by blowing oxygen through the top gun. At the end of decarburization, the molten steel is deoxidized by adding aluminum.

- After the molten steel is deoxidized, the alloy material is added to the vacuum tank through the vacuum hopper.

- The temperature, oxygen and chemical composition of the molten steel are measured.

- After the molten steel is processed, the vacuum pump system is closed in sequence, the vacuum tank is re-pressurized, and it is back to the atmospheric pressure state, and the ladle trolley descends to the track.

- The riser automatically switches from argon blowing to nitrogen blowing.

- The ladle trolley drives to the insulation adding station, blows argon to feed the wire and puts in the insulation.

- The ladle trolley drives to the ladle hanging position. The crane lifts the ladle to the continuous casting ladle turntable.

The above are some of the characteristics of the vacuum refining furnace process, and you are welcome to add. If you have any needs for vacuum furnace, VD VOD refining furnaces and other smelting equipment, please feel free to contact us.

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