DRI is a kind of porous material of low carbon iron by reducing from refined iron powder. DRI has steady chemical elements but lower impurities. Direct reduced iron (Sponge Iron) is mainly used as raw material of steel making in electric stove, cooling agent of steel making in converter, or for use of powder metallurgy after secondary reduction.
In recent years, the steel products are trending towards small-scaled and lightweight, function advanced, and complex, so the proportion of nonmetal and nonferrous metal in steel has increased. It leads to quality indulging of scrap steel. As raw material of electric stove steel, scraps steel is collected from varying sources, whose chemical elements fluctuates greatly, difficult to control. This brings great difficulty for steel making with electric stove. While it can relieve you greatly by adding direct reduced iron (sponge iron ) (30-50% ) in a proper proportion as thinner into scrap steel and improving the steel's homogeneity and physical properties. So, it is not only the substitute of high-quality steel, but also a best material of producing high-quality steel (Tianjin Seamless Steel Tube Company declares the ratio 50% of mixing direct reduced iron (sponge iron). According to foreign report, when the electric stove with the heavy-duty is smelted, productivity increases 10-25% and work rate increases 25-30% by mixing direct reduced iron (sponge iron) with a proportion of 30-50%. Test shows that it can save power consumption 27% per ton, save time 28%, and save oxygen 22%, while steel’s physical performances greatly increased. At this point, mixing a certain amount of direct reduced iron (sponge iron) can not merely improve the production capacity, but also reduce electricity consumption and production cost. According to figure that National Bureau of Statistics, China steel output in 1997 has already reached a hundred million tons, China has became the biggest steel maker in the world, while the consumption of energy per ton is enormous, greatly higher than that of Japan and western countries. It is from technology partly, most from improper manufacturing process. Up to now, the output of electrical steel accounts for 25% of total output in China, greatly lower than the rate 50% in Western Countries. We should do more on the supply of electricity and raw materials, to improve the output of electrical steel. Practice has proved, pure and qualified direct reduced iron (sponge iron) is the ideal raw material of electric stove, which has been generally realized in western developed countries. During the "Ninth Five-Years" Plan Period, metallurgical industrial adjustment --Optimizing the structure of steel, paying attention to the scale and output changes into paying attention to quality and benefit. If raw material still mainly rely on scrap steel, to improve the quality of steel will be very difficult. This is because that nearly 100% of harmful impurity (Sn, As, Cu, etc.)in the scrap steel also remains in the steel.
According to the report, in the past 25 years, the content of Cu in carbon steel increases by 20%, the content of nichrome increases by 1. 2 times, and the content of tin increases by 2 times in U.S.A.. So it will be very difficult for simply using scrap steel to improve the quality of steel-making, but to use direct reduced iron (sponge iron) partly could avoid these questions. So it is very important to use direct reduced iron (sponge iron) when smelting high-quality steel and special steel, such as smelting petroleum casing tube, steel for automobile, nuclear power station and military affairs and so on. We can also say to produce special steel and high-quality steel must be used direct reduced iron (sponge iron).
Therefore, direct reducing iron (Sponge Iron) is the indispensable material for smelting high-quality steel and special steel, it is the high-quality material of electric stove to supply scrap steel's deficiency, and it also can be used as refrigerant of converter steelmaking and powder metallurgy.