Stone source distribution
China iron ore resources have two characteristics: first, there are many poor ores, and the reserves of poor ore resources account for 80% of the total; Second, there are many multi-element composite mines. In addition, the ore body is complex; The upper part of some lean iron deposits is hematite and the lower part is magnetite.
I. Northeast China
Iron ore deposits in Northeast China are mainly Anshan mining area, which is the largest mining area in China at present. Large ore bodies are mainly distributed in Anshan (including Dahushan, cherry orchard, East and West Anshan, etc.). ), Benxi (Nanfen, Waitoushan, Tongyuanbao, etc. ) and Liaoyang (Gongchangling) in Liaoning Province, and some deposits are also distributed near Tonghua in Jilin Province. Anshan mining area is the main raw material base of Angang and Benxi Steel.
Main characteristics of ore in Anshan mining area:
1. Except for a few rich ores, about 98% of the reserves are lean ores, with an iron content of 20-40%, with an average of about 30%. It must be beneficiated, and the iron content after beneficiation can reach more than 60%.
2. The ore minerals are mainly magnetite and hematite, and some are pseudomorphic hematite and semi-pseudomorphic hematite. Its structure is compact and hard, gangue is evenly distributed and dense, mineral processing is difficult, and ore reducibility is poor.
3. Most gangue minerals are composed of quartzite, containing 40-50% silica. Benxi Tongyuanbao iron mine is a kind of autolytic ore, and its alkalinity (Ca+Mg/SiO _ 2) is above 1. Manganese content 1.29-7.5% can replace manganese ore.
4. There are few sulfur and phosphorus impurities in the ore, and the phosphorus content of Nanfen Iron Mine in Benxi is extremely low, which is a good raw material for smelting high-quality pig iron.
Second, North China.
It is mainly distributed in Wu 'an and Fengfeng mining areas in Xuanhua, Qian 'an and Handan areas of Hebei Province. Mining villages and other areas as well as Inner Mongolia and Shanxi. It is the raw material base of Shougang, Baotou Steel, Taigang, Handan, Xuanhua and Yangquan.
The ore in Qian Luan mining area is Anshan-type lean magnetite, which contains acid gangue, less sulfur and phosphorus impurities and good washability.
Hanxing mining area is mainly composed of hematite and magnetite, with iron content of 40%-55%. Gangue contains certain alkaline oxides, and some ores contain high sulfur.
Third, Central and South China.
Hubei Daye Iron Mine is the main iron mine in Central South China, and other places such as Xiangtan, Hunan, Wuyang, Anyang, Henan, Hainan Island, Jiangxi and Guangdong have considerable reserves. These mining areas have become the raw material supply bases for WISCO, Xianggang and large and medium-sized blast furnaces in this area respectively.
Daye mining area is one of the earliest mining areas in China, mainly including Tieshan, Jinshandian, Chengchao and Lingxiang, with abundant reserves. The ore is mainly iron-copper ore, the iron mineral is mainly magnetite, followed by hematite, and the others are chalcopyrite and pyrite. The iron content of ore is 40-50%, and the highest is 54-60%.
Gangue minerals include calcite, quartz, etc. Gangue contains about 28% SiO, which is a solvent (CaO/SiO _ 2 is about 0.3). The ore contains low phosphorus (generally 0.027%), high sulfur (0.0 1- 1.2%) and copper (0.2).
The ore has poor reducibility and is smelted in blast furnace after sintering and pelletizing.
Fourth, East China.
East China iron ore producing areas are mainly Aoshan, Nanshan, Gushan, Taochong, Meishan and Fenghuang Mountain from Wuhu, Anhui to Nanjing, Jiangsu. In addition, Jinling Town, Shandong Province is rich in iron ore resources, and it is a raw material supply base for iron and steel enterprises such as Maanshan Iron and Steel Co., Ltd..
The iron ore in Wuning mining area is mainly hematite, followed by magnetite, and some sulfide minerals such as chalcopyrite and pyrite. Iron ore has a high grade, some rich ore (containing 50%-60% iron) can be directly smelted in the furnace, and some lean ore can be used for blast furnace smelting after beneficiation, sintering and briquetting. The ore has good reducibility.
Gangue minerals include quartz, calcite, apatite and rutile. The impurities of S and P are high (generally 0.5%, as high as 1.6% and S 2%-3% in Meishan Iron Mine). The ore is solvent (such as 0.7-0.9 rich ore in Aoshan and Meishan), and some ores contain.
Verb (abbreviation for verb) Other regions
In addition to the iron ore in the above areas, China's southwest and northwest provinces, such as Sichuan, Yunnan, Guizhou, Gansu and Xinjiang, are also rich in different types of iron ore resources.
Iron ore classification
I. Hematite
The main component of hematite is Fe2O3, that is, iron oxide. There are two polymorphs of Fe2O3 in nature, namely α-Fe2O3 and γ-Fe2O3, in which the mass fraction of Fe is about 69.4300%. The former is stable under natural conditions and is called hematite; The latter is not as stable as α-Fe2O3 in natural conditions, and is in a metastable state, which is called maghemite. ?
Second, magnetite
The main component is Fe3O4, that is, Fe3O4. Each Fe3O4 molecule has two +3 valence iron atoms and one +2 valence iron atom, namely Fe2O3 FeO. The valence of oxygen atom is -2, and the mass fraction of Fe is about 72.438+0%. Equiaxial crystal system.
Three. brown iron ore
Limonite is not a mineral, but a mixture of goethite, lepidolite, epidote, hydrous silica and argillaceous. The chemical composition changes greatly, and so does the water content.
1, goethite α-FeO(OH).
It contains 62.9% iron. Those containing an indefinite amount of adsorbed water are called goethite. Needle-like, columnar, thin-plate or scaly plagioclase system. Usually bean-shaped, kidney-shaped or stalactite-shaped. The cutting surface has a parallel or radial fiber structure. Sometimes it is dense and massive, earthy, and sometimes it is oolitic.
Colors are reddish brown, dark brown to dark brown. Weathered powdered ochre limonite is yellowish brown. The goethite stripes are reddish brown, with hardness of 5-5.5 and specific gravity of 4-4.3. While limonite stripes are generally light brown or yellowish brown, with hardness of 1 ~ 4 and specific gravity of 3.3 ~ 4.
2. Glass fiber γ-FeO(OH).
It contains 62.9% iron. Those containing an indefinite amount of adsorbed water are called FeO (OH) NH2O. Oblique crystal system Common scaly or fibrous aggregate. The color is dark red to black red. The stripes are orange or brick red. The hardness is 4 ~ 5 and the specific gravity is 4.0 1 ~ 4. 1.
Four. ilmenite
The main component of ilmenite is FeTiO3, namely ferrous titanate, in which the mass fraction of Fe is about 36.803 14 10549%. Tripartite system. Diamond crystal. It is often irregular granular, scaly or thick. Above 950℃, ilmenite and hematite form complete isomorphism.
Five, siderite
The main component of siderite is FeCO3, that is, ferrous carbonate, in which the mass fraction of Fe is about 49.09248%, often containing Mg and Mn. Tripartite system. In common rhombohedral, the crystal plane is often curved. Its aggregate is from coarse to fine.
There are also tuberculous, grape-like and earthy. Yellow, light brown yellow (dark brown after weathering), glassy luster. The hardness is 3.5 ~ 4.5, and the specific gravity is about 3.96, which varies with the contents of magnesium and manganese.
Six, pyrite
The main component of pyrite is FeS2, namely ferrous persulfate, in which the mass fraction of Fe is about 46.55 19684580%. Pyrite is often mistaken for gold because of its light brass color and bright metallic luster. The crystal belongs to the sulfide mineral of equiaxed system. The composition usually contains cobalt, nickel and selenium, and has a NaCl crystal structure.
Refer to the above? China Geological Survey-Investigation Report on Iron Ore Resources in China