A Brief History Of Iron Development

There are only three ferrous metals: iron, manganese and chromium. In the survey of land resources and geological and mineral exploration, 157 large and medium-sized mineral areas were newly discovered, including 4 ferrous metal minerals, 73 non-ferrous metal minerals and 34 precious metal minerals.

In 2004, the investment in ferrous metal mining, smelting and rolling processing industry was 154.6 billion yuan, an increase of 40.5%. In 2005, the growth rate of the ferrous metal industry accelerated significantly, and the added value increased by 35.5%. The output of pig iron, crude steel and steel was 27.7 million tons, 29.73 million tons and 31.106 million tons, respectively.

In 2004, the world steel production reached 1,054.8 million tons, the output increased by about 110 million tons, of which China's steel production increased by 52.34 million tons, accounting for 47.73% of the world steel production growth. In 2004, China's steel production reached 272 million tons, which has ranked first in the world for nine consecutive years, and is the combined steel production of Japan, the United States and Russia, ranking second to fourth. China is already the world's largest steel production and consumer, and has become the most concentrated area of steel investment.

Iron is one of the metals known from ancient times. Iron ore is one of the main components of the Earth's crust, iron is widely distributed in nature, but human discovery and use of iron is later than gold and copper. First of all, because the natural elemental state of iron is very rare on the earth, and it is easy to oxidize and rust, plus its melting point (1812K) is much higher than copper (1356K), making it more difficult to melt than copper. The earliest iron found by humans is a meteorite falling from the sky, and the percentage of iron in the meteorite is very high, and it is a mixture of iron and nickel, cobalt and other metals. When the method of melting iron ore has not yet come out, and it is impossible for humans to obtain pig iron in large quantities, iron has been regarded as the most precious metal with mystery.

 

►Properties of iron

It's a shiny, silvery-white metal. Density 7.86 g/cm 3. Melting point 1535℃, boiling point 2750℃. Common valence +2 and +3, with good ductility and thermal conductivity. It also conducts electricity. Pure iron can be both magnetized and demagnetized, and both are very rapid. The ionization energy is 7.870 electron volts. The chemical properties are relatively active, and it is a good reducing agent. If there are impurities, easy to rust in the humid air; Rust is faster in wet air in the presence of acid gas or halogen vapors. Soluble in dilute acid. It can be passivated in concentrated nitric acid. When heated, it can be combined with halogen, sulfur, silicon, carbon, phosphorus, etc. In addition to the formation of +2 and +3 valence oxides, there is also the formation of complex oxides Fe3O4(which is a magnetic oxide). Iron is an indispensable metal in the industrial sector.

 

 

 

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