Molecular Formula | W |
Molar Mass | 183.84 |
Density | 19.3 g/mL at 25 °C (lit.) |
Melting Point | 3410 °C (lit.) |
Boling Point | 5660 °C (lit.) |
Flash Point | -23°C |
Water Solubility | insoluble |
Vapor Presure | 0Pa at 3000℃ |
Appearance | wire |
Specific Gravity | 19.3 |
Color | Silver-gray |
Exposure Limit | ACGIH: TWA 2 ppm; STEL 4 ppmOSHA: TWA 2 ppm(5 mg/m3)NIOSH: IDLH 25 ppm; TWA 2 ppm(5 mg/m3); STEL 4 ppm(10 mg/m3) |
Merck | 13,9884 |
Storage Condition | no restrictions. |
Stability | Stable. Dust is flammable, though not likely to present a hazard if normal good practice is used. |
Physical and Chemical Properties | Tungsten has a density of 19.35g/cm3, close to that of gold, a melting point of 3422 °c and a boiling point of 5927 °c. Tungsten is a silver-white metal with an outer shape like steel, with the highest melting point of all metal elements and a slow evaporation rate. The chemical properties of tungsten is very stable, does not react with air and water at room temperature, does not react with any concentration of hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, however, it can be rapidly dissolved in a mixed acid of hydrofluoric acid and concentrated nitric acid, and has no effect in an alkaline solution. |
Use | Sun-resistant Green Lotus color original R sun-resistant Blue Lake |
Risk Codes | R11 - Highly Flammable R36/38 - Irritating to eyes and skin. R67 - Vapors may cause drowsiness and dizziness R65 - Harmful: May cause lung damage if swallowed R62 - Possible risk of impaired fertility R51/53 - Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R48/20 - R38 - Irritating to the skin |
Safety Description | S6 - Keep under ... (there follows the name of an inert gas). S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S62 - If swallowed, do not induce vomitting; seek medical advice immediately and show this container or label. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S36/37 - Wear suitable protective clothing and gloves. S16 - Keep away from sources of ignition. |
UN IDs | UN 3089 4.1/PG 2 |
WGK Germany | - |
RTECS | YO7175000 |
TSCA | Yes |
HS Code | 81011000 |
Hazard Class | 4.1 |
Packing Group | III |
is a gray-black metal (body-centered cubic crystal) with metallic luster. Melting point 3400 °c. Boiling point 5555 °c. The relative density was 019. 35. The hardness of tungsten is the hardest of the metals, with hardness HB(kgf/mm2) ranging from 200 to 250 for sintered tungsten rods and from 350 to 400 for tungsten rods passed through a rotary hammer. A mixed acid soluble in nitric acid and hydrofluoric acid. Melt with a mixture of sodium hydroxide and sodium carbonate. Slightly soluble in nitric acid, sulfuric acid, Aqua Regia; Insoluble in water, hydrofluoric acid, potassium hydroxide. There are two variants of tungsten, a and B. Type A is a stable body-centered cubic structure at standard temperature and atmospheric pressure. Type B tungsten appears only in the presence of oxygen. It is stable below 630 °c and converts to Alpha tungsten above 630 °c, and this process is irreversible.
industrial production can be prepared by reducing tungsten trioxide with hydrogen; Or the ammonium paratungstate is treated with acid, and then the tungsten trioxide is obtained by the decomposition of the cooked and the reduction of the hydrogen.
tungsten is mostly used to produce cemented carbide and ferrotungsten. Tungsten and chromium, molybdenum, cobalt composition of heat-resistant and wear-resistant alloy for the production of cutting tools, metal surface hardening materials, gas turbine blades and combustion tubes. Tungsten and tantalum, niobium, molybdenum and other components of refractory alloys. Tungsten-copper and tungsten-silver alloys are used as electrical contact point materials. The high-density tungsten-nickel-copper alloy is used as a protective screen against radiation. Wires, rods, sheets, and the like of tungsten metal are used to make parts of electric bulbs, electron tubes, and electrodes for arc welding. Tungsten powder can be burned into a variety of porosity of the filter. FW-1 for large slab, tungsten-rhenium galvanic material. FW-2 for contact alloy, high specific gravity shielding raw materials. FWP-1 for plasma spraying materials.
toxicity of tungsten powder see tungsten trioxide. Product into a clean polyethylene plastic bottle, to tighten the bottle, the plastic bottle is placed in a wooden box, the surrounding with soft fixed, or the product into a polyethylene plastic bag lining the iron drum, 30kg net weight per box (barrel). Products should be stored in dry, ventilated and acid, alkali atmosphere in the warehouse, to prevent oxidation. The product shall be protected from rain and moisture during transportation, and shall not be subject to severe collision. FW-1 and FW-2 storage period should not exceed half a year, FWP-1 storage period should not exceed.
resistivity | 4.9 ***-CM, 20°C |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Introduction | tungsten is a rare metal and an important strategic material. China is a large country producing tungsten, tungsten resources reserves of 5.2 million tons, accounting for 65% of the world's total reserves, production and exports are ranked first in the world. The tungsten resource reserves of Hunan, Jiangxi and Henan provinces rank in the top three in the country, and the tungsten resource reserves of Hunan and Jiangxi provinces account for 55.48% of the country. Hunan is dominated by scheelite, and Jiangxi is dominated by tungsten, and its tungsten resources account for 42.40% of the total tungsten resources. Tungsten is a rare high melting point metal belonging to group VIB of the sixth period (second long period) of the periodic table. Tungsten is a silver-white metal that looks like steel. Tungsten has a high melting point, a low vapor pressure and a low evaporation rate. |
Discovery History | The History of tungsten dates back to the 17th century. At that time, some of the ores, which had been noticed by miners in the Earls mountains in the German state of Saxony, interfered with the reduction of cassiterite and produced slag, gave them some German nickname: "wolfert", "Wolachm". Scheler in 1758, the Swedish chemist and mineralogist krangst discovered a mineral, he called it "tungsten", in Swedish means "heavy stone". He is convinced that this mineral contains an element that has not yet been discovered. Scheelite was discovered in 1781 by Swedish chemist Karl William Scheler and tungstic acid was extracted from it. He believes that a new metal may be obtained by the reduction of tungstic acid. Hosi de Luar and the Fu Tu de Luar brothers in 1783 years, Hosi de Luar and Fu Tu de Luar brothers also extracted tungstic acid from scheelite. In the same year, they used carbon to reduce tungsten trioxide to obtain tungsten powder for the first time. Later, Jöns jacobberzelius and Friedrich Wöhler gave the metal a new name: wolfram, but the name was recognized in Germany and Scandinavian, the United Kingdom, the United States and other countries prefer to use the name "tungsten" given to this metal ". |
Source | tungsten is the 58 most abundant elements found on Earth. There is no elemental substance in nature. Its main source and ore, the main ore is called tungsten or tungsten oxide and a mixture of iron, manganese and tungsten oxide. Tungsten ores (oxides) are mainly found in Russia, China, South America, Thailand and Canada. |
Application | the application of tungsten is very wide, the most common is tungsten carbide (WC) cemented carbide. Such hardmetals are commonly used as durable metals in the metal processing, mining, oil extraction, and construction industries. In addition in the light bulb and vacuum tube in the application of tungsten is also very wide. Tungsten is also commonly used as an electrode. Tungsten is very hard, very tight, so it is ideal to make heavy metal alloys, such alloys are used in armor, heat sink and high density applications such as pressing weight, balancing weight, the compaction of ships and aircraft, etc. Because tungsten is very compact, the Dart tends to contain 80% to 97% tungsten. High speed steel contains tungsten, sometimes 18% tungsten. High temperature alloys for the manufacture of turbine sheets, durable sections and protective layers contain tungsten (Haugh, stellite, etc). Compounds of tungsten may be used as catalysts. |
preparation | methods for preparing tungsten powder include hydrogen reduction, carbon reduction and metal thermal reduction. The most common hydrogen reduction method in modern industry is the primary or secondary hydrogen reduction of tungsten trioxide or blue tungsten oxide. This method can accurately control the grain shape, particle size and particle size composition of tungsten powder. Generally, the blue tungsten oxide doping process is better. |
tungsten target applications | tungsten targets are mainly used in aerospace, rare earth smelting, electric light source, chemical equipment, medical equipment, metallurgical machinery, smelting equipment, oil, and other fields |
species | there are more than ten kinds of major tungsten ores, and there are two main species in China; Tungsten carbide (manganese and iron tungstate) and scheelite (calcium tungstate). 1. Tungsten carbide (FeMn) wo4. Colors are dark gray, light red brown, light brown black, brown hair and iron Brown and other colors. Semi-metallic luster, metallic luster and resin luster. Usually leaf-like, curved -like, granular and dense; Some are plate-like, sharp-columnar and monoclinic crystals, it is often filled with white quartz in the form of veins in the granite and its adjacent rock fractures. Hardness 5-5.5, specific gravity 7.1-7.5. Differential fracture. Friable nature, with weak magnetism. Tungsten carbide is the main raw material for the production of tungsten and tungstate. The conventional process uses the alkali fusion method. 2. Scheelite cawo4. The color is gray-white, and there are also yellow-brown, green and light red. Grease gloss. It is a square crystal system, the formation of double-cone pseudo-octahedral or plate-like crystals, sometimes visible diagonal stripes, which is more common inserted double crystal. Some crystals are in the form of skin shell, kidney, granular and dense block. Hardness 4.5-5; Specific gravity 5.9-6.2. Friable, shell-like or differential fracture. Scheelite emits a beautiful light blue fluorescence when illuminated by a fluorescent lamp. Scheelite is produced in Dayu, Xiushui, Jiangxi, China, Rucheng, Anhua, Linwu, Luanchuan, Yunnan, Wenshan and other places. The above Tungsten minerals can be obtained by gravity separation (shaker, jigging, etc.), flotation, chute, heavy sand method and other methods to obtain black tungsten concentrate or white tungsten concentrate. |
resource distribution | The natural reserve of tungsten in the Earth's crust is 6.2 million tons, and the recoverable reserve is 2.9 million tons. China is a tungsten producing country, tungsten resources reserves of 5.2 million tons, for the 30 foreign tungsten production countries Total Reserves (1.3 million tons) more than three times, the output and export volume of the world's first. The tungsten resource reserves of Hunan, Jiangxi and Henan provinces rank in the top three in the country, and the tungsten resource reserves of Hunan and Jiangxi provinces account for 55.48% of the country. Hunan is dominated by scheelite, and Jiangxi is dominated by tungsten, and its tungsten resources account for 42.40% of the total tungsten resources. tungsten ore in China is generally distributed in the eastern coastal area of Guangdong on both sides of the Nanling Mountain in China, especially in the southern part of Jiangxi, accounting for more than 1/2 of the world's reserves. In addition, Jiangxi (Gannan) large surplus, Xiushui, Hunan Rucheng, Anhua, Linwu, Zixing, Zhuling, Henan Luanchuan, Fujian Ninghua, and Guangxi, Guangdong, Gansu, yunnan and other places. The main producing areas of tungsten ore in foreign countries are Canada, Russia, the United States, North Korea, Mongolia and other countries. |
tungsten target material characteristics | after spraying, sintering of the tungsten target, with a density of 99% or even higher, the average diameter of the transparent texture is 100um or less, the oxygen content is 20ppm or less, and the deflection angle is about 500Mpa. The production of raw metal powder is improved, and the sintering ability is improved, the cost of the tungsten target can be stabilized at a low price. The sintered tungsten target has a high density, has a high level of transparent frame that cannot be achieved by the traditional press sintering method, and significantly improves the deflection angle, so that the particulate matter is significantly reduced. |
safety information | tungsten dust, powder and fine particles will be explosive in the air, sometimes spontaneous explosion. Dust of many tungsten compounds is toxic if inhaled or ingested. |
Use | sun-resistant Qinglian original R sun-resistant blue lake large slab, raw material of tungsten-rhenium thermocouple (FW1), contact alloy, high density shielding material (FW2). for the manufacture of hard or high-temperature alloy, high-speed cutting special steel, and for the bulb filament and the aerospace industry heat-resistant material used as an analytical reagent FW-1 for large slab, raw materials for tungsten-rhenium galvanic couples. FW-2 for contact alloy, high specific gravity shielding raw materials. FWP-1 with plasma spraying materials. |
production method | industrial production can be made by reduction of tungsten trioxide with hydrogen or by acid treatment of ammonium paratungstate, tungsten trioxide was obtained by thermal decomposition, and was prepared by reduction with hydrogen. Hydrogen reduction tungsten trioxide method with hydrogen reduction can be carried out in two stages, the first stage of tungsten trioxide is heated to 450~600 ℃, with hydrogen reduction, the second stage of reduction at 750~1100 ℃, the finished tungsten powder was obtained. Its WO3 H2 → WO2 H2OWO2 2H2 → W 2H2O |
category | spontaneous combustion articles |
toxicity grade | low toxicity |
Acute toxicity | intraperitoneal-rat LD50: 5000 mg/kg |
stimulation data | Skin-rabbits were mild at 500 mg/24 h; eyes-rabbits 500 mg/24 h mild |
flammability hazard characteristics | spontaneous combustion in air; Toxic tungsten oxide smoke released from fire scene |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; The package is sealed |
fire extinguishing agent | water, foam mist |
Occupational Standard | TWA 5 mg/m3; Tel 10 mg/m3 |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |