materials and production processes
First, raw materials
Steel is the source of iron ore, that is, iron (Fe) exists in nature in the form of pure iron in nature is non-existent, mainly consist of iron ore magnetite, hematite, limonite three of these are iron oxides, the difference lies in the way of their oxidation. Iron content in iron ore the higher the better, in theory, the highest iron ore in the iron content of about 72%, iron content above 60% as the rich iron ore. First in a furnace with iron ore into iron reduction (milling iron), and then refined into steel-making furnace Decarburization Gang, scrap can also be renewable in the smelting furnaces.
The use of steel in accordance with the general use made of the nature of various shapes of goods, not only the so-called iron and steel products. Iron and steel products is usually iron ore reduction, melting into a milling iron (smelting and milling), refining iron milling Gang (steel), steel re-rolling, made of a variety of processed steel products, iron and steel products include a broad cast iron, cast steel, forged steel products and processed steel products.
Iron and steel raw materials in the discussion, we have to make out the steel and iron What is the difference? Whether there are different ingredients do?
We are always in their daily lives to steel and iron together referred to as the "steel", shows that steel and iron should be a substance; a matter of fact, from a scientific point of view, steel and iron are slightly different They are the main components of iron, but contained different amount of carbon.
We have always considered the carbon content of more than 2 percent in called "pig iron", which is lower than this value is called "Steel." Therefore, in the process of smelting iron and steel, iron ore at blast furnace (blast furnace) (BF) was smelting into molten pig iron, pig iron and then re-melt on the steel-making furnaces (steel making furnace) in the refining Gang.
The production of iron and steel raw materials needed to be divided into four broad categories discussed: the first category is discussed in a variety of raw materials containing iron ore; The second is the coal and coke; the third category are discussed in the smelting process used to make Melting ballast (slag) of the flux (or flux flux), such as limestone, etc.; the last category is a variety of auxiliary materials, such as scrap materials (scrap), oxygen and so on.
Second, the types and distribution of iron ore
In theory, any compound containing iron or iron ore iron ore can be called. However, in industry or business, the iron ore is not only an element to contain iron, but the value must have the use of do. However, absolute as it is hard to determine whether there is a use of the value of ore, so it is difficult to establish an industry standard for iron ore.
For example, in Europe the poor quality of iron ore production, and low iron content, but because they can not find good minerals, so they put that as the iron ore; and Australia because of good quality with high iron ore inventory, so like the kind used by the European ore in Australia has been that the worthless. Well, in Europe, the iron ore used in the United States steel industry will not be considered to be the iron ore. Further example, in the past were considered too low iron content did not take advantage of the value of the ore, as the present, the industrial and technological progress, the development of many low-cost approach to the rich iron ore of the ingredients, so these low iron content of the ore also has become a valuable iron ore.
Thus, we summed up a conclusion that the industry standard for iron ore is found as the regional supply and demand, changes in industrial technology standards and transport conditions change. To current standards, the average iron ore about 25%, and was known as the value of iron ore there.
Iron compounds are present in the state of nature, especially the existence of iron oxide the amount of state is particularly high.
Several more important now to put forward to explain the iron ore: (first three are the main types)
(1) magnetite (Magnetite) is a kind of iron ore, the main ingredients of Fe3O4, is Fe2O3 and FeO of the complex, showing black-gray, about the proportion of about 5.15, with Fe 72.4%, O 27.6%, with a magnetic . In Mineral Processing (Beneficiation) magnetic separation method can be used when dealing with very convenient; but because of its detailed structure, the less will be restored. Over a long period after weathering into hematite.