Iron ore is a special mineral formation, including iron, as well as its compounds. Ore is considered iron in the event that it contains this element in sufficient quantities in order to be economically viable to extract it.
The main variety of iron ore is magnetic iron ore. It contains almost 70% oxide and iron oxide. This ore is black or steel-gray. Magnetic iron ore in Russia is mined in the Urals. It occurs in the bowels of the Magnetic, High, Grace and Kachkanar mountains . In Sweden, it is found in the vicinity of Falun, Dannemore and Gallivara. In the USA, it’s Pennsylvania, and in Norway, Arendal and Persberg.
In ferrous metallurgy, iron ore products are divided into three types:
- separated iron ore (low in iron);
- sinter ore (with an average iron content);
- pellets (wet iron).
Morphological types
Such iron ore deposits that contain more than 57% of iron in their composition are considered rich. Poor ores include those in which at least 26% of iron. Scientists divided iron ore into two morphological types: linear and plane-like.
Linear-type iron ore is an ore-shaped wedge-shaped body in the zones of bends and earth faults. This type is characterized by a particularly high iron content (from 50 to 69%), but sulfur and phosphorus are contained in such ore in a small amount.
Plane-like deposits are found at the tops of strata of ferruginous quartzites, which are a typical weathering crust.
Iron ore. Application and production
Rich iron ore is used to produce pig iron and is mainly used for smelting in converter and open-hearth production, or directly for iron reduction. A small amount is used as natural paint (ocher) and a weighting agent for clay drilling fluids.
The volume of world reserves of explored deposits is 160 billion tons, and iron contains about 80 billion tons. Iron ore was found in Ukraine, and Russia and Brazil have the largest reserves of pure iron.
World ore production is growing every year. In most cases, iron ore is mined by the open pit method, the essence of which is that all the necessary equipment is delivered to the deposit, and a quarry is built there. The depth of the pit is on average about 500 m, and its diameter depends on the characteristics of the found deposit. After that, using special equipment, iron ore is mined, stored on machines adapted for the transportation of heavy goods, and delivered from the quarry to enterprises engaged in processing.
The disadvantage of the open method is the ability to mine ore only at a shallow depth. If it lies much deeper, you have to build mines. First, they make a trunk resembling a deep well with well-fortified walls. In different directions from the trunk corridors depart, the so-called drifts. The ore found in them is blown up, and then its pieces are raised to the surface using special equipment. Extraction of iron ore in this way is effective, but is associated with serious danger and cost.
There is another way by which iron ore is mined. It is called SRS or downhole hydraulic production. Ore is extracted from underground in the following way: a well is drilled, pipes with a hydraulic monitor are lowered into it and a rock is crushed by a very powerful water jet, which is then lifted to the surface. Mining of iron ore in this way is safe, but, unfortunately, is inefficient. So only 3% of the ore can be mined, and 70% is mined. However, the development of the SRS method is being improved, and there is a high probability that in the future this option will become the main one, displacing mines and quarries.