Industry characteristics

Author:International Labour Organization
Pages:5-5
 
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MEISI05-R-2005-02-0159-1-En.doc
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2. Industry characteristics
2.1. Iron- and steel-making
2.1.1. For most iron-making, the essential features are coke ovens and the blast
furnace, where coke is produced from coal and iron ore is melted (reduced) to produce pig
iron, respectively. The furnace is charged from the top with iron ore, coke and limestone;
hot air, frequently enriched with oxygen, is blown in from the bottom; and the carbon
produced from the coke transforms the iron ore into pig iron containing carbon, with the
generation of carbon monoxide and carbon dioxide. The limestone acts as a flux. At a
temperature of 1,600°C, the pig iron melts and collects at the bottom of the furnace. The
furnace is tapped (i.e. the pig iron is removed) periodically, and the pig iron is cast into
pigs for later use (e.g. in foundries), or is poured into ladles where it is transferred, still
molten, to the steel-making plant. The waste gas from the blast furnace, which is rich in
carbon monoxide, is burned in blast furnace stoves to heat the air blown into the furnace
and may be used as a fuel elsewhere in the steel plant.
2.1.2. Some pig iron is also produced in foundry cupola furnaces. Various processes
exist or are under development for producing iron through the direct reduction of iron ore,
using reducing gases. Such processes may become more important in the future.
2.1.3. The purpose of steel-making operations is to refine the pig iron which contains
large amounts of carbon and other impurities. The carbon content must be reduced, the
impurities oxidized and removed, and the iron converted into a highly elastic metal that
can be forged and fabricated. Alloying agents may be added at this stage. Different types
of melting furnace are used in this process.
2.1.4. Some steel is produced directly from scrap or other iron-containing materials,
most often in electric arc furnaces, without the need for iron ore or coke.
2.1.5. Steel is cast into slabs, billets, bars, ingots and other shapes. Subsequent steps
may include scarfing, pickling, annealing, hot and cold rolling, extrusion, galvanizing,
surface coating, cutting and slitting, and other operations designed to produce a variety of
steel products.
2.2. Occupational hazards
2.2.1. Operations in the iron and steel industry may expose workers to a wide range
of hazards or workplace activities or conditions that could cause incidents, injury, death, ill
health or diseases. These are discussed in the following chapters.

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