De Guzman, Jerwin D.Reyes, Hazel Marie J.

Summary of Report

IRON AND STEEL PROCESSING

Iron is an element while steel is an alloy comprising of iron and carbon.

History of Iron and Steel production

The production of iron by humans began probably sometime after 2000 BCE in south-west or south-central Asia, perhaps in the Caucasus region.  Thus began the Iron Age, when iron replaced bronze in implements and weapons. This shift occurred because iron when alloyed with a bit of carbon is harder, more durable, and holds a sharper edge than bronze.  For over three thousand years, until replaced by steel after CE 1870, iron formed the material basis of human civilization in Europe, Asia, and Africa.  Ironmaking -iron is reduced from its ores

Steelmaking –iron is then refined to obtain desired purity and composition (alloying)

The principal ore used in the production of iron and steel is hematite (Fe2O3) •Other iron ores include magnetite (Fe3O4), siderite (FeCO3), and limonite (Fe2O3-xH2O, where x is typically around 1.5) •Iron ores contain from 50% to around 70% iron, depending on grade (hematite is almost 70% iron) •Scrap iron and steel are also widely used today as raw materials in iron-and steel making

Other Raw Materials in Iron-making

•Coke(C) –Supplies heat for chemical reactions and produces carbon monoxide (CO) to reduce iron ore •Limestone(CaCO3) –Used as a flux to react with and remove impurities in molten iron as slag•Hot gases(CO, H2, CO2, H2O, N2, O2, and fuels) –Used to burn coke

Steel is an alloy of iron containing from 0.02% and 2.11% carbon by weight•Often includes other alloying elements: nickel, manganese, chromium, and molybdenum •Steel alloys can be grouped into four categories: 1.Plain carbon steels 2.Low alloy steels

3.Stainless steels 4.Tool steels

Steel production

When iron is smelted from its ore by commercial processes, it contains more carbon than is desirable. To become steel, it must be melted and reprocessed to reduce the carbon to the correct amount, at which point other elements can be added. This liquid is then continuously cast into long slabs or cast into ingots. Approximately 96% of steel is continuously cast, while only 4% is produced as ingots.

The ingots are then heated in a soaking pit and hot rolled into slabs, blooms, or billets. Slabs are hot or cold rolled into sheet metal or plates. Billets are hot or cold rolled into bars, rods, and wire. Blooms are hot or cold rolled into structural steel, such as I-beams and rails. In modern steel mills these processes often occur in one assembly line, with ore coming in and finished steel coming out.

Casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process

An ingot is a material, usually metal, that is cast into a shape suitable for further processing. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods.

Primary steelmaking

Primary steelmaking involves converting liquid iron from a blast furnace and steel scrap into steel via basic oxygen steelmaking or melting scrap steel and/or direct reduced iron (DRI) in an electric arc furnace.

Secondary steelmaking

Secondary steelmaking involves refining of the crude steel before casting and the various operations are normally carried out in ladles. In secondary metallurgy, alloying agents are added, dissolved gases in the steel are lowered, inclusions are removed or altered chemically to ensure that high-quality steel is produced after casting.

Steel industry

In 1980, there were more than 500,000 U.S. steelworkers. By 2000, the number of steelworkers fell to 224,000.The economic boom in China and India has caused a massive increase in the demand for steel in recent years. Between 2000 and 2005, world steel demand increased by 6%. Since 2000, several Indian and Chinese steel firms have risen to prominence like Tata Steel (which bought Corus Group in 2007), Shanghai Baosteel Group Corporation and Shagang Group. ArcelorMittal is however the world's largest steel producer.

In 2005, the British Geological Survey stated China was the top steel producer with about one-third of the world share; Japan, Russia, and the US followed respectively.

In 2008, steel began trading as a commodity on the London Metal Exchange. At the end of 2008, the steel industry faced a sharp downturn that led to many cut-backs.

The world steel industry peaked in 2007. That year, ThyssenKrupp spent $12 billion to build the two most modern mills in the world, in Calvert, Alabama and Sepetiba, Rio de Janeiro, Brazil. The worldwide Great Recession starting in 2008, however, sharply lowered demand and new construction, and so prices fell. ThyssenKrupp lost $11 billion on its two new plants, which sold steel below the cost of production. Finally in 2013, ThyssenKrupp offered the plants for sale at under $4 billion.

World’s largest steel producer

ArcelorMittal is the world’s leading steel company, with an annual production capacity of around 119 million tonnes ArcelorMittal is the successor to Mittal Steel, a business originally set up in 1976 byMr. Lakshmi N. Mittal and also the owner of arcelormittaloperations in more than 60 countries, steelmaking facilities in more than 20 countries, and are the leader in all the main steel markets.ArcelorMittal’s long business produces billets, blooms, rebars, wire rod, sections, rails, sheet piles and drawn wires, as well as supplying both seamless and welded tubular products.

ArcelorMittal timeline:

1976Mr Lakshmi N Mittal establishes PT Ispat Indo (as greenfield steel project) in Indonesia. 1989The company, as Caribbean Ispat, operates Iron and Steel Company of Trinidad and Tobago (Iscott). 1994Caribbean Ispat exercises its option to acquire Iscott. 1995Ispat International Ltd and Ispat Shipping are set up in the UK 2012ArcelorMittal sells 25% of its 75% stake of Baffinland Iron Mines Corporation and becomes equal partners with Nunavut Iron Ore. 2013ArcelorMittal enters into a 50/50 joint venture partnership with Nippon Steel & Sumitomo Metal Corporation (“NSSMC”) to acquire 100% of ThyssenKrupp Steel USA (“TK Steel USA”) from ThyssenKrupp for an agreed price of US$1,550 million.  The steel processing plant is situated in Calvert, Alabama, with a total capacity of 5.3 million

tonnes including hot rolling, cold rolling, coating and finishing lines.

Uses of steel

Iron and steel are used widely in the construction of roads, railways, other infrastructure, appliances, and buildings. Most large modern structures, such as stadiums and skyscrapers,bridges, and airports, are supported by a steel skeleton. Even those with a concrete structure employ steel for reinforcing. In addition, it sees widespread use in major

Other common applications include shipbuilding, pipelines, mining, offshore construction,aerospace, white goods (e.g. washing machines), heavy equipment such as bulldozers, office furniture, steel wool, tools, and armour in the form of personal vests or vehicle armour (better known as rolled homogeneous armour in this role).

Environmental and Public Health Issues

Air PollutantsAir pollutants from iron- and steel-making operations have historically been an environmental concern. These pollutants include gaseous substances such as sulphur dioxide, nitrogen oxide and carbon monoxide.

Sulphur dioxide a potent acid rain maker. Acid rain damages forests and crops, changes the makeup of soil, and makes lakes and streams acidic and unsuitable for fish. Continued exposure over a long time changes the natural variety of plants and animals in an ecosystem. Moreover, sulfur dioxide is associated with increased risk of respiratory diseases, asthma, and premature death.Nitrogen oxide Nitrogen oxides in the air can significantly contribute to a number of environmental effects such as acid rain and eutrophication in coastal waters .Carbon monoxide Carbon monoxide affects the environment in several ways. First, it elevates the amount of methane in the atmosphere and then oxidizes into carbon dioxide. This eventually leads to global warming

Waste Water Contaminants Steel works discharge large volumes of water to lakes, rivers and streams, with additional volumes being vaporized while cooling coke or steel. Contaminants include suspended solids, heavy metals and oils and greases

Suspended solids Suspended solids (SS) are the main waterborne pollutants discharged during steel production. They comprise mainly iron oxides from scale formation during processing; coal, biological sludge, metallic hydroxides and other solids may also be present. Their

presence at higher levels may lead to discolouration of streams, de-oxygenation and silting.

Heavy metals Steel-making process water may contain high levels of zinc and manganese, while discharges from cold-rolling and coatings areas may contain zinc, cadmium, aluminium, copper and chromium. These metals are naturally present in the aquatic environment; it is their presence at higher than usual concentrations that creates concern about potential effects on humans and the ecosystems.

Oils and greases Oils and greases may be present in waste water in both soluble and insoluble forms. Most heavy oils and greases are insoluble and are relatively easily removed.In addition to the question of toxicity, the biological and chemical oxygen demand (BOD and COD) of oils and other organic compounds can decrease the oxygen content of the water, thus affecting the viability of aquatic life.