Discover a small history
Greek, Roman times people will use bismuth, but do not know is a metallic element, bismuth name from the German white metal (Wismut). Around the 16th century, G. Agricola converted the name to bismntum. In the long run, people were mistaken for lead , tin , silver , and sputum . It was not until 1753 that C. Ggeoffroy and T. Bergman determined that cockroaches were an element. After 1860, cockroaches began to take shape on an industrial scale.
Awkward nature
It is brittle and shiny. The crucible increases in volume when solidified, and the expansion ratio is 3.3%. Niobium is the most reversible metal, and the resistivity increases and the thermal conductivity decreases under the action of a magnetic field. In addition to mercury , niobium is the metal with the lowest thermal conductivity. Niobium and its alloys have a thermoelectric effect. The selenium and tellurium compounds of germanium have semiconducting properties. The hydrazine is slightly oxidized in humid air at room temperature, and is heated to a melting point to burn to form antimony trioxide. The hydrazine reacts slowly with hydrochloric acid, reacts with sulfuric acid to release sulfur dioxide, and reacts with nitric acid to form nitrate.
Awkward resources
The presence of small amounts of bismuth in nature, the main minerals are: bismuthinite, bubble bismuth, bismuth China, natural bismuth, lead bismuth side, Ling bismuth, copper and bismuth.é“‹ There are few separate deposits, often associated with lead, zinc , copper, tungsten, molybdenum , tin and other minerals, and its industrial grade of separate mining is 0.5%. The world's annual output is about 4,400 tons. China's base metal volume is 500,000 tons, and in 1993 it was about 1052 tons.
Preparation of cockroaches
The smelting of smelting is divided into two steps: smelting and refining. The method of smelting varies from raw material to raw material. When bismuth sulfide concentrate, mixed mineral bismuth and bismuth oxide, bismuth oxide, bismuth oxychloride, and slag refining bismuth or the like as a raw material, mixed melting method, with the appropriate amount of scrap iron, soda ash, fluorite powder, coal powder, The mixture is smelted in a reverberatory furnace to obtain a coarse crucible, which is sent to refining. Calcium magnesium dross to bismuth metallurgical refining process lead pyrometallurgical produced as a raw material refining method is: first dross is heated, so that the lead contained therein removed sinking. The slag is further heated, and after melting, lead chloride or chlorine gas is introduced to remove calcium and magnesium to obtain a bismuth-rich lead bismuth alloy, which is then sent to refining. Refining is generally divided into four steps: oxidation of arsenic , antimony, antimony, etc.; addition of zinc and silver; chlorination of lead and zinc; high temperature dechlorination.
Use of cockroaches
The main use of bismuth is in the form of metal for the formulation of fusible alloys and in the form of compounds for use in medicine. The former has a melting point range of 47-262 ° C, and the most commonly used are binary, ternary, quaternary, and pentary alloys composed of metals such as lead, tin, antimony, and indium . By varying the percentage of these metals in the alloy, a range of alloys with different melting points and different physical properties are available; these alloys are used in fire-fighting installations, thermal elements for automatic sprinklers, safety plugs for boilers and compressed air cylinders. , solder, molten bath medium for metal heat treatment, etc. Niobium alloys have the property of not shrinking when condensed, and are used for casting printed typefaces and high precision molds. Bismuth and its alloys often as cast iron, steel, aluminum alloys and additives to improve the machinability of the alloy. A niobium alloy containing 11% niobium is used to manufacture an infrared detector. The antimony tin and antimony cadmium alloys act as auxiliary electrodes for the selenium rectifier. A magnetometer is fabricated by utilizing the characteristic that the resistivity is drastically reduced under the action of a magnetic field. Manganese alloy can be used to make permanent magnet alloys. The thermal neutron absorption cross section of the crucible is small and has a low melting point and a high boiling point, and can be used as a heat transfer medium for a nuclear reactor. Sputum is widely used in the manufacture of thermoelectric components for solar cells. Cesium-Bi-Ag alloys for photo amplifier. Silver sulfide ruthenium is used in the manufacture of semiconductor instruments. The cadmium telluride temperature difference element is used for the alarm device.
Train Engine Parts :Train Engine Valve,Train Engine Valve Seat ,train Engine Valve guide ,train engine piston ,train engine Piston Pin and other Engine Parts .
All our products had adopte with ISO/TS16949 quality system authorities,with advanced technology introduced from Japanese FUJI,Strict testing equipment ,we promise each of our Engine Part with best quality and most competitive price.
Train Engine Parts
Train Engine Parts,Train Parts,Parts Train,Train Parts For Sale
Hebei Zhonghai Shipping Accessories Manufacturing Co., Ltd. , https://www.zhonghaiship.com