Manganese metal, a Swedish chemist, chlorine the discoverer club Le pyrolusite found in 1774. At that time, this pyrolusite known as the “Manganese”, the club Le use this name as the name of the new element,.
1774 Swedish chemist Scheler (C.W.Scheele) manganese and its nature, “a text sent to the Academy of Sciences of Stockholm; He is considered the discoverer of manganese. 1774 the the Swedish chemist Gunn (J.G.Gahn) with She Leti pure pyrolusite powder and charcoal in the crucible heating 1h, button-shaped metal manganese block. 1895 the Goldschmidt (H.Goldschmidt) obtained patented aluminum heat production of. The beginning of the 20th century, electricity silicon thermal production of . 1923 of Armand (A.I.Allmand) and Cam Harrell (A.N.Camplell) reported that electrolytic manganese sulfate aqueous solution obtained manganese. February 1936, the U.S. Bureau of Mines completed electrolytic manganese sulfate aqueous solution system manganese semi-industrial tests. Electrical manganese company in 1938 to start industrial-scale production of electrolytic manganese. American the manganese chemical company in 1963, was completed and put into operation the annual output of 2000t low carbon ferromanganese plant with molten salt electrolysis method. China Jilin Ferroalloy Plant in May 1957 to test the electrical silicon thermal production of manganese metal. Zunyi Ferroalloy Plant began in 1959, to the industrial-scale silicon thermal power production of manganese metal. 1958 Shanghai the Association Chengchang smelter start trial production of electrolytic manganese.
The metal manganese tilting refining smelting furnace. On the stove till after the first add some lime pad in the bottom. Lime above adding a small amount of high-silico-manganese silicon alloy. The arc after adding manganese-rich slag and lime mixture. Gradually adding manganese silicon alloy melting process to help melt and reduce the basicity. Full penetration after all manganese silicon alloy, adjust the silicon content of qualified baked. Manganese metal containing Mn> 93.5%, Si <1.8%, Fe <2.8%, P <0.06%, C <0.20%. Production lt metal manganese (Mn95% ~ 98%) consume manganese-rich slag (Mn4.8%) 1.9 to 2.0t, the high-silico-manganese silicon alloy about 0.62t, lime (CaO> 90%) about 2.0t , fluorspar about 0.2t. Energy 3000 ~ 3400kW · h. Manganese recovery rate of 72% to 75%.
Manganese is a silver-gray metal than iron much like iron, but softer. If the manganese containing small amounts of impurities – carbon or silicon, and it becomes very hard, and is very brittle. However, the use of pure manganese metal and not too wide, because it prone to rust than iron, in the damp air, not while they become gray, has lost its luster – generated on the surface of a layer of manganese oxide. Say, the melting point of manganese off than iron lower mechanical strength than steel, while the price of inferior steel is much more expensive and therefore almost no production of manganese metal, and the mass production of iron and steel.
Manganese is the most important use is the manufacture of alloys – manganese steel.
Manganese steel temper is very strange and interesting: 2.5-3.5% manganese steel, low-manganese steel obtained simply brittle like glass, a knock on the broken. However, if more than 13% of manganese is added, made of high-manganese steel, then it becomes hard and rich toughness. High manganese steel heated to a pale orange, very soft, very easy to carry out a variety of processing. In addition, it is not magnetic, and will not be attracted by the magnet. Now, a large number of people with manganese steel manufacturing steel mill, ball bearings, bulldozers and excavators bucket often by grinding components, as well as the railroad tracks, bridges, etc.. The roof of the audience hall of the new Shanghai Culture Square, a novel grid structure, with thousands of root manganese steel steel pipes welded together. 76 meters in the vertical cross 138 meters of the fan-shaped hall, not a pillar in the middle. Manganese steel as a structural material, very strong, and materials than other steel Province, the average per square meter of roof only 45 kg manganese steel. 1973 Hing health Shanghai Stadium (to accommodate eighteen thousand people), also manganese steel truss roof structure, material. High manganese steel manufacturing military helmets, tanks, steel armor, armor-piercing warhead. Refining manganese steel, manganese 60 to 70% of the soft tin and iron ore is smelted mixed together.
In addition to manganese steel, manganese steel is also important manganese alloys, manganese steel containing 30% manganese, having a good mechanical strength. Composed by 84% steel, 12% of manganese and 4% nickel Bangladesh Nie alloy (also known as copper-manganese-nickel Qi), its resistance is very small change with temperature, is used to manufacture the precision electrical instruments .
The manganese compound is manganese dioxide. In nature, will have a lot of natural manganese dioxide – Pyrolusite. People will know as early as in ancient times pyrolusite. Manganese dioxide is a black constitutive color powder. Black powder dry-cell batteries is manganese dioxide. The manganese dioxide can be catalyzed oxidation of the oil, is often added in the paint, in order to accelerate paint drying speed. In the manufacture of glass, often added thereto, manganese dioxide, because it can eliminate the green of the glass, so that the green glass becomes colorless and transparent.
Another important manganese compound is potassium permanganate (commonly known as “gray manganese oxide). Potassium permanganate is purple needle-like crystals. Just add a little potassium permanganate would be sufficient to make a bucket of water turned purple. Potassium permanganate is a strong oxidizing agent, can sterilization. Mug next in public places, often stood a bucket of purple disinfection of water, known as “gray the manganese water”, in fact, this is the potassium permanganate solution, the concentration of one-thousandth. However, this water can not drink into the stomach, because it has emetic role in medicine as of gastric lavage agent and emetic. In the analysis of the chemical, potassium permanganate is often used as the oxidant, famous potassium permanganate method is to use it as titrant for chemical analysis. Often become manganese dioxide, potassium permanganate is reduced. Gray manganese water after use, under often some black scum, and that is manganese dioxide.
In addition, the manganese carbonate is a white pigment, commonly known as “manganese white”, and manganese sulfate in agriculture, for seed germination agent or for manganese fertilizer – trace elements fertilizer.