Pig iron production

In 1979, there were 168 blast furnaces in the United States, most located in Pittsburgh and Chicago, and these produced ca 8 x 10 t of pig iron. By 1992, most of the blast furnaces in the Pittsburgh area had disappeared. Only 44 blast furnaces were operating in the United States, producing ca 4.7 x lO t of pig iron. The drop in pig iron production can be attributed to decreased and more efficient use of steel products, competition from steel imports, and rapid growth of scrap-based steelmaking. 

Miscellaneous Fuels A variety of gases have veiy minor market shares. These include reformed gas, oil gases, producer gas, blue water gas, carbureted water gas, coal gas, and blast-furnace gas. The heating values of these gases range from 3.4 to 41 MJ/m (90 to 1100 Btii/ftq. They are produced by pyrolysis, the water gas reaction, or as by-products of pig-iron production. 

As indicated, pig iron production requires input of a reducing agent. Stahlwerke Bremen uses plastic waste as a substitute for fuel oil. Plastics are injected into the blast furnace in a similar way to coal powder or fuel oil. In order to remove fibres and metal particles a separation takes place. Large particles are separated via a screen of > 18 mm. The smaller plastic waste particles (< 18 mm) go to the injection vessel. There, an injection pressure of about 0.5 MPa is built up. Via a pneumatic process the plastics can be dosed and discharged into the blast furnace. The bulk density of the plastics has to be 0.3 tonnes/m. ... 

PIG IRON. Product of blast-furnace reduction of iron oxide in the presence of limestone. About half the ore is converted to iron. Average analysis is 1% silicon, 0.03% sulfur, 0.27% phosphorus, 2.4% manganese, 4.6% carbon, balance iron, Pig iron is the basic raw material for steel and cast iron. In metal terminology a pig is a bar or ingot of cooled metal. 

Oxygen has been used for enriching the blast supplied to blast furnaces m pig-iron production, with consequent economy in the consumption of coke. This process yields particularly favourable results in the manufacture of ferro-silieon.3... 

Dechlorination of mixed plastics from household waste, after separation from municipal solid waste, and co-injection with coal into a blast furnace for pig iron production. The aim is to replace pulverised coal in this process (www.vinyl2010.org). 

Steel derived from new pig iron produced from ores and from recycled steel has better properties than iron for most uses. World steel production currently hovers around 1.33 times world pig iron production, a reflection of the recycled metal content. Again, we have some countries, like China and the U.S.A., whose national steel consumption exceeds even their very large scale of production (Table 14.2). 

Blast furnace production of iron allows the hot, newly reduced product to trickle through the bed of heated coke to the hearth. Since carbon is somewhat soluble in molten iron, pig iron usually contains from 3 to 4.5% carbon. It also contains smaller percentages of other reduced elements such as silicon, phosphorus, manganese, etc., generated by the same reducing processes that yielded the iron (Table 14.3). Primarily from the effect of the high-carbon content on the iron crystal structure, the blast furnace product is brittle, hard, and possesses relatively low-tensile strength. Hence the crude pig iron product of the blast furnace is not much used in this form. 

John Flack Winslow moved with his family at age five to Albany NY, where he was educated until age seventeen. He then entered a commercial house as a clerk. In 1832 he secured the management of the Boston agency of the New Jersey Iron Company. In 1833, he went into the iron industry on his own account and was engaged successfully in the pig iron production in Bergen and Sussex counties NJ. 

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