Industry and business

how to produce iron ore

how to produce iron ore

Allah, the Almighty, revealed a complete Surah (chapter) in the Quran called “Al-Hadid” (Iron) and stated: {وأنزلنا الحديد فيه بأس شديد ومنافع للناس}”And We sent down iron with its great might, benefits for humanity” Besides its essential need, iron ore is one of the most sought-after industrial minerals. It is utilized in almost all industries, whether small or large, and without iron, industrial development would not have progressed to its current state. It is our duty to accurately explain how iron is produced.

Iron is one of the most important metallic minerals in the world, with no other metal equaling its significance and global consumption. It is also one of the earliest metallic elements discovered and utilized by humans in their daily lives. It is usually found dispersed in the Earth’s crust or through meteorites that fall from space. Iron and its alloys possess various and diverse properties in terms of heat resistance, tensile strength, rust resistance, flexibility, and magnetism. It has been one of the most suitable metals for weapons and structural supports throughout history. Additionally, iron plays vital biological roles within organisms. Its compounds are involved in the formation of chlorophyll in plants and the composition of nuclear proteins in living cells. It is also widespread in body fluids and other organs, being a component of hemoglobin.

Overview of Iron Minerals

Different minerals, including iron, exist in impure forms in the Earth’s surface and deep layers. The quantities present and extracted vary depending on the type of mineral and its availability in nature. Moreover, their concentration and degree of purity vary from one location to another. These minerals are usually mixed with various impurities, thus referred to as mineral ores. The well-known and commonly used types of iron are not raw iron minerals; they are alloys of raw iron with other elements such as carbon, silicon, manganese, phosphorus, and sulfur.

Iron is usually extracted in blast furnaces or electric furnaces, resulting in several forms, each with distinct properties suitable for industrial use, such as steel and cast iron. However, raw iron is relatively soft and not used in industrial applications. Iron minerals are easily magnetized, have good thermal and electrical conductivity, and are represented chemically by the symbol Fe.

Iron Ore Extraction Sources

خامات استخراج الحديد الخام

As mentioned, iron does not exist as a pure ore. It is typically found accompanied by impurities and other elements. The types of iron vary depending on their properties and associated elements. Consequently, iron production relies on five main ore types:

1- Magnetite

This type is known as magnetic iron ore because it is black in color with a specific gravity of 5.2 and a hardness of 5.5-6.5. Magnetite accounts for approximately 72% of iron ore and is distinguished by its strong magnetism. It is chemically composed of iron and oxygen. It is usually found in veins within igneous or metamorphic rocks, which accounts for its relative purity due to a lower impurity content. Magnetite is one of the least widespread iron ores globally, and its famous deposits can be found in Sweden, northern Spain, and Egypt.

2- Hematite

Hematite is one of the most important iron sources worldwide due to its widespread occurrence. It is found in extensive sedimentary rocks and also occurs as a secondary mineral in igneous rocks. Hematite appears in flat or curved crystalline forms, and sometimes in lamellar shapes. It ranges in color from gray to black, and its streak is characterized by a dark red hue. This type is prevalent in Aswan, Egypt, and the Lake Superior region in the United States, which is the largest iron-producing area in the world.

3- Siderite

Siderite is a less widespread but valuable iron mineral. It contains around 48% iron and is free of impurities such as sulfur or phosphorus. This mineral has a hardness ranging from 3.75 to 4.25. It crystallizes in the trigonal crystal system, taking on specific crystal forms, usually with curved and striated faces. Its color varies from yellow to dark brown or black.

Siderite is commonly found in thermal waters in Europe, especially in Yorkshire. Most of its formations are associated with sedimentary rocks from the Jurassic period and are linked to barite and fluorite.

4- Pyrite

Pyrite is considered the poorest quality among iron ore types, with iron content ranging around 45% or less. This mineral is typically found in the form of cubic or massive aggregates, granules, or spheres. It is characterized by its brassy yellow color, resembling gold, which earned it the nickname “fool’s gold” due to its resemblance during extraction. Pyrite forms in sedimentary rocks and occasionally in metamorphic rocks.

Pyrite is widespread in sulfide veins and is chemically composed of iron sulfide (FeS2). Spain, Japan, and Russia are the countries with the highest production of this type of iron.

5- Limonite

Limonite is known for its yellow or brown color, depending on the impurities present in it. It is a lower-quality type of iron ore, with iron content reaching around 60%. Limonite is usually found in sedimentary rocks and is composed of iron, hydrogen, and oxygen. It forms as a result of deposits from iron carbonate in clay rocks, which were deposited in freshwater during the Carboniferous geological period. The most famous occurrences of limonite are in the Lorraine region between France and Germany, as well as the Bahariya Oasis in Egypt.

Iron Ore Production

انتاج الحديد الخام

Iron is one of the most widely used metallic materials in industries, representing the backbone of any industrial economy. The process of producing raw iron is not an easy one, as it involves various physical and economic complexities. However, iron is typically extracted from raw materials by smelting them to remove impurities. Nevertheless, pure iron itself does not possess practical properties; it is soft, with low resistance to rust and corrosion. Therefore, it is only useful when mixed with other elements such as carbon, silicon, and manganese. There are three main stages in iron production:

1- Iron Ore Extraction

This stage follows mining, where workers extract iron from mines. Iron does not exist in nature in a pure form but is found combined with other elements such as oxides, carbides, and silicates, along with a high percentage of carbon ranging from 4 to 5%. It also contains impurities from the Earth’s crust, which means iron is extracted from the ground in an impure form. Its quality and concentration vary from one location to another, as well as its purity depending on the extraction site.

2- Iron Ore Preparation

This stage involves the initial processes carried out on the extracted ores before they are sent to blast furnaces for iron ore extraction. The processes include:

  • Crushing: The extracted rocks, which are usually large and difficult to transport or handle, are crushed using specialized machines called crushers or mills.
  • Screening: The crushed materials are sorted according to their size, separating smaller and larger particles. This process is done using electromagnetic separators that attract iron-containing parts and separate non-magnetic materials. The broken ore is then passed through classifiers for further size classification.
  • Agglomeration: This process involves collecting small stones from the iron ore and the resulting dust into larger, suitable-sized particles that can be smelted in furnaces.
  • Washing: After crushing, the iron ore passes through a pressurized water stream to remove adhering dust, sand, and clay. The water stream also carries away the impurities and foreign materials from the ore.
  • Roasting: After the washing process, the ore must be thoroughly dried. This is achieved through the roasting process, where the iron ore passes through hot-air furnaces at a specific temperature to evaporate the washing water and remove a portion of impurities.

3- Iron Ore Extraction

Iron ore is extracted from iron ore fines in specialized furnaces to convert it into raw iron as a preliminary stage. This is usually done using blast furnaces, but occasionally ore is extracted in electric furnaces as well. Recently, iron ore extraction using hot reduced gases such as hydrogen, methane, and carbon monoxide has begun, with different heating methods employed. In both methods, chemical means are used by burning coke, converting it into carbon monoxide, and generating high heat, as is the case with blast furnaces. Electric power is also used for heating in blast furnaces. However, the reduction of iron oxide occurs in the same manner in both methods, using carbon from coke to remove oxygen from iron oxide. This means that coke must be used in both methods to reduce the iron oxides present in the ore.

Top Iron Ore Producing Countries

Global iron ore production reached approximately 2.4 billion metric tons in 2020, according to data from the U.S. Geological Survey, which represents a slight decrease compared to the previous year.

Australia and Brazil are among the largest producers of iron ore in the world, with Australia being the largest. Its production exceeded 900 million metric tons of iron ore in 2021, accounting for about 37.5% of the world’s total production. Brazil follows with the second-largest production of around 380 million metric tons, closely followed by China with a production of 240 million metric tons. As a result, Australia holds the highest iron ore reserves, estimated at 51 billion metric tons, with over 90% of iron extraction mines located in Western Australia.

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