File Name: production of iron and steel .zip
- The Entire History of Steel
- The modern technology of iron and steel production and possible ways of their development
- How Is It Made? An Infographic of the Iron and Steel Manufacturing Process
- 23.3: Metallurgy of Iron and Steel
The blast furnace is the first step in producing steel from iron oxides.
Steel production is a hour-a-day, day-a-year process, dependent on a consistent supply of raw materials and huge amounts of energy. High demand for iron ore, coke and scrap steel, increasing energy costs, and industry consolidation have prompted steel producers to develop new methods for gaining efficiency to remain competitive. The production methods using raw materials have improved significantly over the past decade, and scrap-based production is accounting for a larger portion of the total steel supply.
The Entire History of Steel
The ores used in making iron and steel are iron oxides, which are compounds of iron and oxygen. The major iron oxide ores are hematite, which is the most plentiful, limonite, also called brown ore, taconite, and magnetite, a black ore. Magnetite is named for its magnetic property and has the highest iron content. Taconite, named for the Taconic Mountains in the northeastern United States, is a low-grade, but important ore, which contains both magnetite and hematite.
Also, the cost of shipping iron ores from the mine to the smelter can be greatly reduced if the unwanted rock and other impurities can be removed prior to shipment. This requires that the ores undergo several processes called "beneficiation. Taconite ore powder, after beneficiation, is mixed with coal dust and a binder and rolled into small balls in a drum pelletizer where it is then baked to hardness. About two tons of unwanted material is removed for each ton of taconite pellets shipped.
The limestone or burnt lime is used as a fluxing material that forms a slag on top of the liquid metal. This has an oxidizing effect on the liquid metal underneath which helps to remove impurities. Approximately two tons of ore, one ton of coke, and a half ton of limestone are required to produce one ton of iron. There are several basic elements which can be found in all commercial steels.
Carbon is a very important element in steel since it allows the steel to be hardened by heat treatment. Only a small amount of carbon is needed to produce steel: up to 0. The metal manganese is used in small amounts 0. Sulfur is difficult to remove from steel and the form it takes in steel iron sulfide, FeS allows the steel to become brittle, or hot-short , when forged or rolled at elevated temperatures. Sulfur content in commercial steels is usually kept below 0. A small quantity of phosphorus usually below 0.
Phosphorus in larger quantities reduces the ductility or formability of steel and can cause the material to crack when cold worked in a rolling mill, making it cold-short. Silicon is another element present in steel, usually between 0.
The silicon dissolves in the iron and increases the strength and toughness of the steel without greatly reducing ductility. The silicon also deoxidizes the molten steel through the formation of silicon dioxide SiO 2 , which makes for stronger, less porous castings.
Another element that plays an important part in the processing of steel is oxygen. Some large steel mills have installed their own oxygen plants, which are located near basic oxygen furnaces.
Oxygen injected into the mix or furnace "charge" improves and speeds up steel production. Steel can be given many different and useful properties by alloying the iron with other metals such as chromium, molybdenum, nickel, aluminum , cobalt, tungsten, vanadium, and titanium , and with nonmetals such as boron and silicon.
The modern technology of iron and steel production and possible ways of their development
In steelmaking, impurities such as nitrogen , silicon , phosphorus , sulfur and excess carbon most important impurity are removed from the sourced iron, and alloying elements such as manganese , nickel , chromium , carbon and vanadium are added to produce different grades of steel. Limiting dissolved gases such as nitrogen and oxygen and entrained impurities termed "inclusions" in the steel is also important to ensure the quality of the products cast from the liquid steel. Steelmaking has existed for millennia, but it was not commercialized on a massive scale until the late 14th century. An ancient process of steelmaking was the crucible process. In the s and s, the Bessemer process and the Siemens-Martin process turned steelmaking into a heavy industry.
The ores used in making iron and steel are iron oxides, which are compounds of iron and oxygen. The major iron oxide ores are hematite, which is the most plentiful, limonite, also called brown ore, taconite, and magnetite, a black ore. Magnetite is named for its magnetic property and has the highest iron content. Taconite, named for the Taconic Mountains in the northeastern United States, is a low-grade, but important ore, which contains both magnetite and hematite. Also, the cost of shipping iron ores from the mine to the smelter can be greatly reduced if the unwanted rock and other impurities can be removed prior to shipment.
In the changing global market scenario for raw materials for the steel industry, a number of novel ironand steelmaking process technologies are being developed to provide the steel companies with economically-sustainable alternatives for ironand steel-making. In addition, the steel industry is also focusing on reduction of energy consumption as well as green-house gas GHG emissions to address the crucial subject of climate change. Climate change is presenting new risks to the highly energyand carbon-intensive, iron and steel industry. The industry needs to focus on reduction of energy consumption as GHG emissions to address climate change. Development of alternate ironand steelmaking process technologies can provide steel companies with economically-sustainable alternatives for steel production. For managing climate change risks, novel modeling tools have been developed by Hatch to quantify and qualify potential energy savings and CO 2 abatement within the iron and steel industry. Evaluation of existing operations have shown that most integrated plants have GHG and energy abatement opportunities; on the other hand, the best-in-class plants may not have a lot of low-risk abatement opportunities left, even at high CO 2 price.
How Is It Made? An Infographic of the Iron and Steel Manufacturing Process
The steel industry has grown from ancient times, when a few men may have operated, periodically, a small furnace producing 10 kilograms, to the modern integrated iron- and steelworks, with annual steel production of about 1 million tons. The largest commercial steelmaking enterprise, Nippon Steel in Japan, was responsible for producing 26 million tons in , and 11 other companies generally distributed throughout the world each had outputs of more than 10 million tons. Excluding the Eastern-bloc countries, for which employment data are not available, some 1. That is equivalent to about tons of steel per person employed per year—a remarkably efficient use of human endeavour. Iron production began in Anatolia about bc , and the Iron Age was well established by bc.
Steel is an alloy of iron with typically a few tenths of a percent of carbon to improve its strength and fracture resistance compared to iron. Many other elements may be present or added. Because of its high tensile strength and low cost, steel is used in buildings , infrastructure , tools , ships , trains , cars , machines , electrical appliances , and weapons.
23.3: Metallurgy of Iron and Steel
The process of turning raw product into finished stainless steel is a lengthy one, but it can be simplified into six steps. To create pure steel, the products that go into it- lime, coke and iron ore- must be made into iron. These are all put into a blast furnace and melted down to create what is called molten iron or hot metal. The iron still has many impurities at this point, and they will have to be removed to ensure the metal is not brittle. To get the impurities out, the molten metal is infused with scrap steel. Oxygen will be forced through the furnace as well, which gets out a lot of the carbon and other impurities. For electric furnaces, electricity will be forced through the furnace and the same results can be achieved.
The early application of iron to the manufacture of tools and weapons was possible because of the wide distribution of iron ores and the ease with which iron compounds in the ores could be reduced by carbon. For a long time, charcoal was the form of carbon used in the reduction process. The production and use of iron became much more widespread about , when coke was introduced as the reducing agent. Coke is a form of carbon formed by heating coal in the absence of air to remove impurities.
In early times when coal was consumed in far greater proportions in steel production, the trend was to site integrated plants either near the coal source, or near.
The story of steel begins long before bridges, I-beams, and skyscrapers. It begins in the stars. Billions of years before humans walked the Earth—before the Earth even existed—blazing stars fused atoms into iron and carbon. Over countless cosmic explosions and rebirths, these materials found their way into asteroids and other planetary bodies, which slammed into one another as the cosmic pot stirred. Eventually, some of that rock and metal formed the Earth, where it would shape the destiny of one particular species of walking ape.