uranium,natural
URANIUM
CAS: 7440-61-1
Molecular Formula:
uranium,natural - Names and Identifiers
uranium,natural - Physico-chemical Properties
| Molar Mass | 238.03 |
| Density | 1.01 g/mL at 25 °C |
| Melting Point | 314-316°C (dec.) |
| Boling Point | 4160.06°C (estimate) |
| Solubility | Aqueous Base (Slightly) |
| Appearance | silvery-white orthorhombic crystals |
| Color | Pale Brown |
| Storage Condition | Refrigerator |
| Physical and Chemical Properties | Physical properties uranium is a silvery-white, lustrous, heavy, mildly radioactive metal. When exposed to air or water, its appearance can change due to oxidation. Its color is darkened by brass, from Brown to charcoal gray. A powder, fine powder, Crumb, or carapace is rapidly oxidized to produce a dark or flat dark gray or brown color. Uranium is almost as hard as steel and much denser than lead. There are 26 isotopes of uranium. Three of them are considered stable because they have such a long half-life and have not yet all decayed into other elements and are therefore still present in the crust. These three are uranium 234, with a half-life of 2.455 x 10 5 years, accounting for 0.0054% of the uranium found on Earth. The half-life of uranium 235 is 703.8 × 10 6 years, accounting for 0.724% of the Earth's uranium; The half-life of uranium 238m is 4.468 × 10 9 years, most of the Earth's supply of uranium is 99.2742% of that found in nature. |
| Use | A brief introduction to radioactive metal elements. Fuel for nuclear reactions. Uranium is a silver-white metal, almost as hard as steel, with a high density (relative density of about 18.95). Before the development of nuclear energy, it was used to make yellow glass. Uranium is the most atomic number element in nature. In 1841 E. Paley (1811-1890) dissociated metallic uranium, although prior to this uranium had been recognized in the case of pyrilobites. It is also hidden in mica uranium, vanadium potassium uranium and monazite; Mainly in Canada, Australia, South Africa and. There are three isotopes of natural uranium: uranium -238(99.283%), uranium -235(0.711%) and uranium -234(0.006%). The half-life of uranium -238 is 4.51 × 109 years, which can be used to date rocks and as fuel for fast neutron reactors. The most important isotope in the nuclear industry is uranium -235, which is used in * thermal neutron reactors. Some reactors use metal fuel, while others use uranium dioxide (UO2). Other oxides are U3O8 and uo3. The volatile gas uranium hexafluoride (UF6) separates isotopes of uranium by gas diffusion. Atomic number 92, atomic weight 238.0289, melting point 1135 ℃, boiling point 4134 ℃. |
uranium,natural - Risk and Safety
| Hazard Symbols | T+ - Very toxic |
| Risk Codes | R20 - Harmful by inhalation R34 - Causes burns R53 - May cause long-term adverse effects in the aquatic environment R33 - Danger of cumulative effects R26/28 - Very toxic by inhalation and if swallowed. |
| Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S20/21 - |
| UN IDs | UN 3264 8/PG 3 |
| WGK Germany | 3 |
| HS Code | 28441000 |
| Hazard Class | 7 |
| Packing Group | Commercial |
| Toxicity | Three isotopes (234U, 235U, 238U) exist, and a large number of uranium salts are known. They present both toxic and radiological hazards. The most important use of uranium is in the nuclear energy industry, but uranium compounds are also used in ceramics, as catalysts and in certain alloys. Entry into the body can occur during a variety of processes involved with the mining, processing or use of uranium and its compounds, and is probably largely by inhalation of dusts, fumes, etc. or by ingestion. Acute uranium toxicity is primarily nephrotoxicity. About 50% of plasma uranium is bound, as the uranyl ion, to bicarbonate (HCO23 ), which is filtered by the glomerulus. As a result of acidification in the proximal tubule, the bicarbonate complex dissociates followed by reabsorption of the HCO23 ; the released UO21 then becomes attached to the membrane of the proximal tubule cells. Loss of cell function follows, as evidenced by increased concentration of glucose, amino acids, and proteins in the urine. 2,3-Mercapto-1-propanol (British Anti-Lewisite, BAL) is ineffective as a therapeutic agent for uranium poisoning; CaEDTA is recommended. Chronic uranium toxicity appears to be radiation related, the effects being similar to those of ionizing radiation. In humans, cancer of the lung, bone, and lymphatic system are all known to occur. |
uranium,natural - Upstream Downstream Industry
| Downstream Products | Isobutylene 3-Methylbutyl 3-methylbutanoate Thorium(IV) nitrate tetrahydrate. diammonium diuranium heptaoxide |
uranium,natural - Uses and methods of synthesis
Discovery History
the element uranium was discovered by a German chemist, Martin craprot. In 1789, in his laboratory in Berlin, he dissolved the pyrilite in nitric acid and neutralized it with sodium hydroxide, and successfully precipitated a yellow compound (probably sodium uronate). Craput assumes that this is an oxide of an unknown element, and is heated with charcoal, resulting in a black powder. He erroneously believes that this is the newly discovered element, but the powder is actually the oxide of uranium. He named this new element after the discovery of Uranus by William Herschel eight years ago, which itself was named after Uranos, the god of the Greek myth. Similarly, the Neptunium after the uranium is named after the Neptunium, and the Plutonium after the Neptunium is named after the sequences of the platonia.
In 1841, professor of analytical chemistry at the conservation oire National Schools of Arts et Métiers in Paris, yukin-melsio pirigo, heated uranium tetrachloride with potassium, the first separation of uranium metal. In the 19th century, people were not aware of the dangers of uranium, so the development of a variety of daily use of uranium, including the history of ceramic and glass coloring.
In 1896, Henry becoller discovered radioactivity in a laboratory in Paris using the element uranium. Becoller put the potassium salt of uranium sulfate (K2UO2(SO4)2) on the film and placed in the middle of the drawer. After removal, he found that the film appeared in the fog image. He concluded that uranium would emit an invisible light or Ray, leaving an image on the film.
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Natural uranium is used to make fuel for nuclear power plants; Depleted uranium is the remaining product. Some alloys will have a slower oxidation rate, remain silvery white, and then appear brass-colored. No odor was noted. Uranium is used as a rich source of enriched energy. Uranium is present in most rocks in concentrations of 2-4 parts per million and is as common in the Earth's crust as tin, tungsten, and molybdenum. Uranium is present in seawater and can be recovered from the ocean.
The high density of uranium means that it can also find use in a boat keel and serve as a counterweight for the control surface of an aircraft as well as a radiation shield. It is well known that uranium metal reacts dangerously with carbon tetrachloride, chlorine, fluorine, nitric acid, nitric oxide, selenium, sulfur and water (in subdivided form). When decomposed by fire, uranium metal smoke or oxide will be generated. Radioactive progeny (daughters),th 234,pro 234,t234m (transferable) are produced by natural radioactive decay; They are the source of most penetrating radiation. These isotopes can be concentrated in the case of metal melting, condensation or dissolution, and may increase the observed external dose rate. Many industries involved in the extraction, processing and processing of uranium can also release it into the environment. The inert uranium industry may continue to release uranium into the environment. Uranium processing also releases it into the environment.
uranium is important as a nuclear fuel. U can be converted to fission by the following reactions: 238U(n,& gamma;)& rarr;239U-β-& rarr;239Np-β-& rarr;239Pu can achieve this nuclear conversion in a "breeding" reactor where it is possible to produce more new fissionable material than is used to sustain a chain reaction. 235U is of greater importance because it is critical for the utilization of uranium. 235U in natural uranium in the incidence of only 0.72%, in the case of slow neutron fission, so can be made by natural uranium and suitable moderator (such as heavy uranium) A self-sustaining fission chain reaction takes place in the constructed reactor using water or graphite alone. 235 if desired, U can be enriched by gas diffusion and other physical processes and used directly as nuclear fuel instead of natural uranium, or as an explosive.
Source
uranium is the 44th most abundant element on Earth. It mainly exists in the theory of slope, but can also be extracted from ore, such as uranium ore (UO2), carnote [K 2(UO22 VO 4 ], calcium iron ore [Ca(UO 2)2(PO 4 μ2]. Phosphate ore [Ca 3(PO 4+2] and monazite. These ores are found in Africa, France, Australia and Canada, and in Colorado and New Mexico in the United States.
yellow glass was found near Napoli, Italy, with more than 1% uranium oxide, dating back to 79 A. D. Klaproth identified an unknown element in asphalt amphibole and attempted to separate the metal in 1789. Clearly, this metal was first isolated in 1841 by Peligot, which reduced anhydrous chloride with potassium. Uranium is not as rare as before. It is now thought to be more abundant than Mercury, antimony, silver or cadmium, and its content is as much as molybdenum or arsenic. It is found in a variety of minerals, such as pitch amphibole, uranyl, carnote, aurite, uranyl fentanyl, natalite and pyrophyllite. It is also found in phosphate rock, lignite, monazite sand and can be commercially recycled from these sources. Large deposits of uranium mines are located in Utah, Colorado, New Mexico, Canada and elsewhere. Uranium can be produced by reduction of uranium halides with alkali metals or alkaline earth metals or by reduction of uranium oxides with calcium, aluminum or carbon at high temperatures. Metals can also be produced by electrolytically dissolving KUF5 or UF4 in a molten mixture of CaCl2 and NaCl. High purity uranium can be prepared by thermal decomposition of uranium halides on a hot wire.
Last Update：2024-04-10 22:29:15
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Downstream Products for uranium,natural
Isobutylene
3-Methylbutyl 3-methylbutanoate
Thorium(IV) nitrate tetrahydrate.
diammonium diuranium heptaoxide
3-Methylbutyl 3-methylbutanoate
Thorium(IV) nitrate tetrahydrate.
diammonium diuranium heptaoxide