What is secondary refining?

Secondary refining refers to the refining outside the traditional steelmaking furnace (such as open hearth furnace, refining furnace and electric furnace). The main tasks of refining are deoxidation, desulfurization, dephosphorization, decarburization, inclusion removal, alloying and fine adjustment of composition.

Brief introduction of secondary refining furnace

Statistics on the world crude steel output show that the world crude steel output has continued to grow in ups and downs in the past 30 years. The yield increases due to the increase of continuous casting ratio. At present, the crude steel produced by LD Steel Plant accounts for 60% of the world's total steel output. The steel produced by electric furnace steel plant is close to 40%.

In the past 15 years, the vacuum processing capacity of the 15 EU Member States has been increasing. At present, more than 80% of the steel production can be vacuum treated. Ladle furnaces for secondary refining were first introduced into electric furnace mills. In recent years, the use of ladle furnace in BOF steel plant is also growing steadily. At present, more than 30% of the steel output of the 15 EU Member States is secondary refined in ladle furnace.

In fact, continuous casting technology was developed in Japan and Europe in the early 1970s. Later, it was introduced into steel mills. At present, the continuous casting ratio in these two regions reaches about 95%. The development trend of the United States is the same. It took only 3-4 years to make the current continuous casting ratio reach about 95%. In the next few years, the continuous casting ratio of these countries will certainly increase. According to statistics, the world's continuous casting output accounts for about 85% of the steel output. In the next few years, this figure may rise to about 90%.