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Facilities

   Without changing our traditional integrated production system, we have introduced a state-of-the-art electric furnace that recycles scrap into new steel products, enabling us to consume less energy and significantly reduce environmental pollution.

    This new ECOARC electric furnace system is a groundbreaking steelmaking facility that utilizes the most advanced environment-friendly technologies. In addition to greatly reducing dioxin emissions, it enables energy-saving, automation, labor-saving, and work environment improvements.

    The facility is actually equipped with two furnaces, a heat-retention furnace and a heating furnace, and a cantilevered stand for roughing and intermediate stages. For finishing it employs a block mill, which is rare for round bar rolling. So, as well as saving energy, the ECOARC system allows a huge leap in product quality.

1. Scrap yard

    This yard is used to stock scrap iron, an important raw material in steelmaking. At our scrap yard, we classify scrap into various categories and conduct strict inspection and quality control. The scrap yard occupies a total area of 4,700 m2, sufficient to store approximately 35,000 tons of scrap iron. This is the largest indoor scrap yard capacity of any electric arc furnace steelmaker in the Kansai region of Japan. By using efficient magnetic cranes and a speedy material acceptance system, and applying strict quality control and storage for each category of material, we can rapidly load scrap iron into our ECOARC™ furnace.
     Like this, we are promoting the valuable recycling of scrap iron, a precious resource.

2. Electric furnace

    
     The electric furnaces we use to melt steel scrap are ECOARC furnaces, which are environment-friendly and highly efficient. When steel scrap is melted, high-temperature exhaust gas is generated in the furnace. This hot gas is directed into a shaft filled with steel scrap, thereby reducing the quantity of electrical energy required to melt the scrap and significantly cutting electricity consumption.The exhaust gas treatment system, which is a supplementary equipment to the electric furnace, burns off harmful substances in the exhaust gas generated during melting, thereby reducing the burden on the environment. The result is a revolutionary electric furnace that is both efficient and environmentally friendly.

3. Ladle furnace

     The job of the ladle furnace is to remove impurities from the molten steel melted in the electric arc furnace and adjust and homogenize the composition of the molten steel to meet the required standard. To ensure the quality of the finished product, the LF heats the molten steel using an arc and agitates it with argon gas, to remove impurities and achieve a uniform composition. To arrive at the required steel specification, ferroalloys such as carbon, silicon, and manganese are added.


 

4. Continuous casting

     After the molten steel is adjusted to the correct composition, it is conveyed to a continuous casting machine. The molten steel is poured into a mold in the continuous casting machine. As it is continuously drawn, the steel slowly cools and hardens from the outside in, by means of spray cooling. Like this, the molten steel is finally cast into 140 mm square bar. The lengths of cast bar are then cut to specified lengths to form semi-finished products called “billets.” Finally, the billets are visually inspected, weighed, and then transported to the rolling mill.

1. Heating furnace

     The heating furnace heats the billets transported to the rolling mill uniformly to a temperature of approximately 1,000°C, which is hot enough to enable the steel to be rolled. Our energy-efficient heating furnaces are fueled by natural gas (LNG) and equipped with regenerative burners. A regenerative burner is designed for high-efficiency waste heat recovery by alternately igniting one of two sets of burners with built-in heat reservoirs, at an interval of tens of seconds.

2. Rolling mill

    In this process, the billets heated in the heating furnace are passed between two rolls to reduce their cross-sectional area and lengthen them to achieve the desired shape. The rolling is divided into rough, intermediate and finishing lines, with 19 stands in total. The final rolls are engraved with section, grade, and size marks, which are then transferred to the products.

3. Cooling beds

    The rolled materials are uniformly air-cooled on cooling beds and straightened to prevent bending. A cooling bed is approximately 105 meters long and typically has about 70 to 90 meters of rolled products lined up on it.

4. Cold shear

    After products are cooled on the cooling bed, they are cut further into a certain number of pieces and specified lengths (3.5 to 12.0 m, every 0.5 m). For example, 150 pieces of D10, 90 pieces of D13, and 60 pieces of D16 are cut simultaneously.

5. Bundling machine

    We have small and large bundling machines to bundle products in specific numbers. For example, for D10, 12 bundles of 50 pieces (=600 pieces); for D13, 10 bundles of 30 pieces (=300 pieces); for D16, 10 bundles of 20 pieces (=200 pieces).
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