Other Industries

Iron- and steel-making • 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 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 periodically, and the pig iron is cast into pigs for later use, 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. • 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. • 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. • 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. • 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.
Occupational hazards: 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. Types of risk in steel and Iron: most common causes of injury and illness in the iron and steel industry: (i) exposure to controlled and uncontrolled energy sources; (ii) exposure to mineral wools and fibers; (iii) inhalable agents (gases, vapors, dusts and fumes); (iv) skin contact with chemicals (irritants (acids, alkalis), solvents and sensitizers); (v) fire and explosion; (vi) extreme temperatures; (vii) radiation (non-ionizing, ionizing); (viii) electrical burns and electric shock; (ix) manual handling and repetitive work; (x) exposure to pathogens (e.g. legionella); (xxi) lack of OSH training; (xxii) inadequate accident prevention and inspection; (xxiii) inadequate emergency first-aid and rescue facilities; 1. Physical hazards: Noise, Vibration, Heat and cold stress, Ionizing radiation, Non-ionizing radiation, 2. Chemical hazards: Chemicals in the workplace, . Inhalable agents (gases, vapours, dusts and fumes), Asbestos, insulation wools, 3. Safety hazard: Confined space, Control of hazardous energy, Work equipment and machinery guarding, Cranes and hoists, falling objects, Slips, trips and falls