Iron Extraction and Steel Production Processes
Iron Extraction and Steel Production
Iron Ore Extraction Process
The process begins with the extraction of iron ore from the mine, where all the raw material is collected. Once extracted, the ore is transported to a processing area where it is crushed into a fine, dust-like consistency.
This fine mineral powder (along with its impurities) is then transferred to a series of trays equipped with rotating paddles and water. This step aims to separate the earth and isolate as much iron-rich material as possible.
Next, the material is dried and moved to agitators, which rotate to form spherical masses that are subsequently hardened. This process is known as pelletizing. At this stage, the iron material contains oxygen, which needs to be removed.
To eliminate the oxygen, the mineral spheres are placed in a large oven. Gas is injected into the oven, reacting with the oxygen and causing it to be released, leaving behind pure iron ore.
This iron ore, now in the form of spherical pellets, serves as the raw material for the steel industry. In some industries, instead of pellets, the iron is formed into small pads, about the size of a soap bar, known as briquettes.
Steel Production Process
This material becomes the feedstock for the steel industry. Steel is created in large ovens at high temperatures. Carbon, along with other materials like magnesium, vanadium, manganese, and nickel, is added to the iron. The specific combination of materials depends on the desired type of steel and its intended use.
Steel is an alloy composed of iron and carbon, containing less than 1.8% carbon. It can acquire very different properties through mechanical and thermal treatment.
Steel Production
Currently, steel is obtained from liquid iron, with the carbon content regulated along with sulfur, phosphorus, and other elements. Previously, steel was obtained directly from iron ore. This was achieved by reducing iron ore with charcoal, which, in the hottest part of the furnace, transformed into steel (Catalan forging procedure). Over time, increased production led to larger furnaces, and the operation was divided into two phases:
- Acquisition of pig iron (blast furnace)
- Steel obtained from the decarburization of pig iron (converter furnace and hearth furnaces)