Products containing iron minerals according to their mineral composition, can be divided into four categories: magnetite, hematite, limonite and siderite. Due to their different chemical composition, crystal structure and geological conditions, various iron ores have different external morphology and physical properties. C, Z shape roll forming machine and C&Z interchangeable roll forming machine. C purline, Z purline, H beam and others are used for big house building. They are the frame of the house. Normally speaking, the thickness of the material is between 1.5-3.0mm. So for the roll forming machine, it has high standard requirements." It can be widely used in the large and medium-sized enterprise civil construction, such as plant,warehouse,locomotive shed,hanger,exhibition,theatre,stadium and so on. CZ Purlin Roll Forming Machine C Z Purlin Roll Forming Machine,Cz Purlin Roll Forming Machine,C Purlin Machine,Purlin Machine Botou Hongyuan Forming Machine Co.,Ltd , https://www.tilemakingmachinery.com
(1) The main iron-bearing mineral of magnetite is magnetite, and its chemical formula is Fe 3 O 4 , in which FeO=31%, Fe 2 O 3 =69%, and theoretical iron content is 72.4%. Such ore may contain TiO 2 and V 2 O 5 composition composite ore, called magnetite, titanium or vanadium titanium magnetite. It is rarely encountered in natural pure magnetite ore, and some of the magnetite is often oxidized into semi-artificial hematite and imaginary hematite due to surface oxidation. The so-called imaginary hematite is the oxidation of magnetite (Fe 3 O 4 ) to hematite (Fe 2 O 3 ), but it still retains the shape of the original magnetite, so it is called imaginary hematite.
Magnetite has strong magnetism, crystals are often octahedral, and a few are rhombohedral dodecahedrons. Often aggregate into a compact mass, color streak iron black, semi-metallic luster, the relative density of 4.9 to 5.2, a hardness of 5.5 to 6, no cleavage, mainly gangue silicates and quartz. Poor reduction, generally containing harmful impurities such as sulfur and phosphorus .
(2) Hematite Hematite is an anhydrous iron oxide ore with a chemical formula of Fe 2 O 3 and a theoretical iron content of 70%. This ore often forms a huge deposit in nature, and it is the main ore of industrial production in terms of burial and mining.
The iron content of hematite is generally 50% to 60%, and contains less harmful impurities such as sulfur and phosphorus. The reduction is better than that of magnetite. Therefore, hematite is a relatively good ironmaking raw material.
Hematite has both native and wild, regenerated hematite magnetite that loses its magnetic properties after oxidation, but still preserves the pseudomorphic hematite of the crystal shape of magnetite, often contained in illusory hematite. Some residual magnetite. Sometimes hematite also contains some weathering products of hematite, such as limonite (2Fe 2 O 3 •3H 2 O).
Hematite has a semi-metallic luster, the crystallizer hardness is 5.5-6, the earthy hematite hardness is very low, no cleavage, the relative density is 4.9-5.3, only weak magnetic, the gangue is silicate.
(3) Limonite The limonite is hydrous iron oxide ore, which is formed by weathering of other ores. It is the most widely distributed in nature, but it is rare to have large deposits. Its chemical formula is nFe 2 O 3 •mH 2 O (n=1 to 3, m=1 to 4). Limonite is actually a mixture of goethite (Fe 2 O 3 •H 2 O), hydroarticular iron ore (2Fe 2 O 3 •H 2 O) and iron oxide and shale containing different crystal water. consist of. Most of the iron-bearing minerals in limonite are in the form of 2Fe 2 O 3 •H 2 O.
Generally, the iron ore content of iron ore is 37% to 55%, and sometimes the phosphorus content is high. The limonite has strong water absorption, and generally absorbs a large amount of water. After roasting or heating into the blast furnace, the free water and the crystal water are removed, and the porosity of the ore is increased, which greatly improves the reducibility of the ore. Therefore, limonite is better than hematite and magnetite. At the same time, the iron content of the ore is increased correspondingly due to the removal of moisture.
(3) The siderite iron ore is carbonate iron ore, the chemical formula is FeCO 3 , and the theoretical iron content is 48.2%. In nature, there is less industrial iron ore than other three ores. Siderite is easily decomposed and oxidized into limonite. Generally, the amount of iron is not high, but after the decomposition of CO 2 by heat, not only the iron content is significantly increased but also becomes porous, and the reducing property is good.