How can the blast furnace smelting pig iron reduce carbon, and what method can reduce the carbon content in hot metal?
The definition of pig pig iron is an alloy of iron and carbon carbon content more than 2%, pig iron carbon content is generally in 2%--4.3%, including C, SI, and Mn, S, P and other elements, is the use of iron ores in blast furnace smelting products. According to the different form of carbon in pig iron, it can be divided into several kinds, such as steelmaking pig iron, casting pig iron and nodular cast iron. Pig iron performance: pig iron is hard, wear-resisting, casting good, but pig iron is crisp, can not forge. [editor this paragraph]2, various traits of pig iron, introduction, use carbon steel-making pig iron mainly exists in the form of iron carbide, the white section, usually called white iron. The pig iron is hard and brittle, and is generally used as raw material for steelmaking.
Cast iron in carbon flake graphite form exists, its fracture is gray, usually known as gray iron. Because of its soft and lubricated graphite, casting pig iron has good cutting, wear resistance and casting properties. But its resistance to strength is not enough, it can not be forged, and can only be used to make a variety of castings, such as casting all kinds of machine tools, bed seats, iron pipes and so on. Ductile iron to carbon in the form of spherical graphite, which is far better than the mechanical properties of gray cast iron and close to steel, it has excellent casting, machining and wear resistance, has a certain flexibility, widely used in the manufacture of gear, crankshaft, piston and a variety of advanced casting machine parts. In addition, there are silicon, manganese, nickel or other elements particularly high in pig iron, called alloy pig iron, such as ferrosilicon, ferromanganese, etc., commonly used as steelmaking raw materials. The addition of certain alloy pig iron in steel-making can improve the performance of steel.
The production, from the top (usually roof is composed by Bell and hopper of modern blast furnace is the valve bell and bell less top) constant load of iron ore, coke, flux, from the lower part of blast furnace tuyere blowing hot air, is injected into the oil, coal or natural gas as fuel. An iron ore in a blast furnace; mainly iron and oxygen compounds. At high temperatures, carbon and carbon monoxide produced by the carbon and carbon combustion in the coke and the jet blow out the iron from the iron ore, which is called reduction. The iron ore is produced by reduction reaction, and the molten iron is discharged from the taphole. In the iron ore, the ash in the gangue, coke and blowing material is combined with the flux of limestone added into the furnace to produce slag, which is respectively discharged from the taphole and the slag outlet. Gas is derived from the top of the furnace and is used as industrial gas after dust removal. Modern blast furnaces can also use the high pressure at the top of the furnace to generate electricity with some of the exported gas. The reduction gas in the blast furnace is produced by the burning of the fuel in front of the tuyere. This process produces two major streams of motion: one is the rising hot coal stream, and the other is the descent of the charge stream (iron ore, coke, flux, etc.). All reactions in the blast furnace occur in the opposite motion and interaction between the gas and the charge. It includes the furnace heating, evaporation, volatilization and decomposition; iron and other elements of the reduction; desulfurization slag and pig iron melting, non iron oxide charge; the formation of cementite and iron iron; furnace and gas between the heat exchange and so on, is a series of physical and chemical reactions combined. [Edit]]4, the chemical composition of pig iron, iron in addition to iron, but also contains carbon, silicon, manganese, phosphorus and sulfur and other elements.
