Electric Arc Furnace: Clean Production Technology for Electric Arc Furnace Steelmaking

2020年5月12日星期二

Clean Production Technology for Electric Arc Furnace Steelmaking

Development of Clean Production Technology for Electric Arc Furnace Steelmaking

Cleaning technology includes both internal and external aspects of improving the cleanliness of steel and reducing the load on the external environment. It is a production technology that consumes waste steel materials from society and recycles. It does not consume non-renewable resources and uses the cleanest energy-electrical energy. The development of electric arc furnace steelmaking itself is the development of clean production. In addition, the clean development of EAF steelmaking technology is as follows.

(1) Clean steel production.
① Increase the proportion of pure iron source in raw materials (such as direct reduction iron and molten iron);
② Low-oxygen smelting, control the end molten steel Wr0≤450 × 10;
③ Slag modification;
④ Clean steel refining process;
⑤ Molten steel protection pouring;
⑥ Electromagnetic brake and large inclusion control technology.

(2) Reduce the environmental load.
① Use clean energy in electric arc furnace steelmaking;
② Use desi process to reduce the amount of slag;
③ Promote gas recovery process technology;
④ Develop electric arc furnace scrap preheating technology;
⑤ Refining slag steel-making return utilization technology;
⑥ Dust recovery and treatment technology.

Major Technological Progress in Recent Years

Electric arc furnace steelmaking production technology has made great progress in recent years. Following the ups and downs of compact small steel mills in the 1960s in the 20th century, it changed the unique situation of the joint venture. In recent years, some short-flow steel mills using cutting-edge technology integrated arc furnaces have emerged.

(1) Cremona ESP Headless Rolling Strip Plant of Alvedi, Italy. The company built the world's first Arvedi ESP headless rolling strip steel plant, including one 250t electric arc furnace, two 250t ladle refining furnaces and ESP headless rolled strip production line. The designed annual production capacity is 2 million tons, which can produce strip steel with a thickness of 0.8 ～ 12.0mm and a width of 1590mm.

(2) Crawfordsville Plant of Nucor Corporation, USA. After the transformation of the company's electric arc furnace steelmaking workshop, there is no heating device between the casting machine and the hot rolling stand. The strip passes through the hot rolling stand, that is, the thickness of the finished product is 0.7-2.0mm and the width is 2000mm. The designed annual output capacity is about 50 million tons. Using the Castrip process, due to the high cooling rate, short solidification time, and high pulling speed (generally 8O ~ 1500m / min), it has high productivity and can obtain extremely fine microstructure.

(3) MesabiNuggetITmk3 factory of Kobe Steel Corporation of Japan. ITmk3 (IronTeChnologyMarkm) is known as the third-generation ironmaking method. It is a coal-based direct reduction technology that uses a rotary hearth furnace to produce high-quality pig iron jointly developed by Kobe Steel Corporation of Japan and Midland Corporation of the United States. Pulverized coal directly obtains molten iron. Using this technology, iron ore powder can be smelted into slag-free, uniformly sized, and close to pure granulated iron within 10 minutes.