Which iron ore is often used for iron making?
Industrial iron ore with the iron content accounted for more than 85% of the total iron containing iron minerals named. Iron minerals are divided into iron oxide (Fe2O3, Fe3O4), iron oxide (Fe2O3.nH2O) aqueous and iron carbonate (FeCO3). The use of blast furnace iron ore is divided into hematite (red Fe2O3, magnetite ore) (black ore) Fe3O4, Fe2O3nH2O limonite and siderite FeCO3.
Limonite is iron oxide ore containing crystal water, the color is light brown to dark brown or black, loose tissue, reduction is better. The theory of limonite iron content is not high, generally 37% to 55%, but after being heated to remove water of crystallization, the iron content increased relatively, and the porosity increase, reduction of to improve.Siderite for carbonate iron ore, the color was light yellow brown, grey theory. The iron content is not high, only 48.2%, but the thermal decomposition of CO2 release, not only improve the iron content, and a porous structure, a very good reduction. Therefore, despite the low iron content, smelting value still which is very high.
Magnetite in the scratches on the porcelain fracture is black, dense and hard tissue, small porosity, reduction is difficult. Magnetite can be seen as a combination of Fe2O3 and FeO, Fe2O369%, FeO31%, the theory of iron content of 72.4%. in the nature of pure magnetite rarely seen, due to the different degree of oxidation, Fe2O3 composition of magnetite the increase of FeO content reduced. Magnetite is magnetic, which is the most prominent feature of magnetite.
It is characteristic of hematite in the porcelain section scratches on reddish brown, non-magnetic. Soft, easily broken, easy reduction. The highest iron content is 70%. but there is a kind of hematite in gamma Fe2O3 morphology, the crystalline structure is compact and the scratch is dark brown, but also has strong magnetism, similar to the magnetite.
