Ladle Refining Technology and Energy Conservation

Ladle Refining Technology and Energy Conservation

Ladle refining refers to the process of transferring the refining tasks that need to be completed in the traditional steelmaking furnace (electric arc furnace or converter), such as desulfurization, deoxidation, removal of harmful gases and non-metallic inclusions, and adjustment of composition and temperature, to a ladle or special container outside the furnace to achieve better smelting results.

With the development of modern industry, the capacity of electric arc furnaces used in steelmaking is constantly expanding. Correspondingly, the capacity of furnace transformers is also continuously increasing. In particular, continuous casting technology, developed to further improve steel quality and save energy, has stringent requirements for the uniformity of steel composition and temperature, which ordinary electric arc furnaces can no longer meet. From an energy-saving perspective, the residence time within the electric arc furnace should also be shortened. Given these reasons, whether from the perspective of energy conservation or improving steel quality, a new steelmaking process is needed, and ladle refining has thus emerged.

The development of modern electric arc furnace steelmaking has placed increasingly higher demands on the compactness of the process. The melting and minor oxidation processes are typically completed within the electric arc furnace, a process known as primary refining. The remaining processes are completed in refining facilities, a process called refining.

The essence of ladle refining is to subject the molten steel to vacuum treatment or the introduction of inert gas to create the necessary chemical, thermodynamic, and kinetic conditions, thereby achieving effective deoxidation, degassing, and inclusion removal.

The effects of ladle refining are roughly manifested in the following aspects:

(1) Significantly improved steel quality. In particular, refined molten steel has the significant advantages of low gas content and fewer inclusions.

(2) Shorten smelting time

(3) Simplify the process and reduce energy consumption

(4) Reduce production costs

The contribution of ladle refining to energy conservation is mainly reflected in:

(1) Shortening the residence time in the electric arc furnace makes the steelmaking process more compact, greatly shortening the overall steelmaking process time, thereby saving electricity;

(2) The modern electric arc furnace steelmaking model of electric arc furnace + refining + continuous casting has extremely high requirements for the smoothness of the entire smelting process. Transferring some of the tasks originally performed by the electric arc furnace to the refining process is beneficial to process matching, especially to the modern short-process production organization centered on the rhythm of the continuous casting machine. A smooth process makes the entire process interconnected, greatly improving production efficiency, thereby achieving the effect of energy conservation.