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  • hafnium
  • These zirconium minerals generally have a hafnium content that varies from a few tenths of 1 percent to several percent. (britannica.com)
  • For some purposes separation of the two elements is not important: zirconium containing about 1 percent of hafnium is as acceptable as pure zirconium. (britannica.com)
  • Hafnium, present in all zirconium ores, must be scrupulously removed from the metal intended for reactor uses because hafnium strongly absorbs thermal neutrons. (britannica.com)
  • Separation of hafnium and zirconium is generally accomplished by a liquid-liquid countercurrent-extraction procedure. (britannica.com)
  • In the procedure, crude zirconium tetrachloride is dissolved in an aqueous solution of ammonium thiocyanate, and methyl isobutyl ketone is passed countercurrent to the aqueous mixture, with the result that the hafnium tetrachloride is preferentially extracted. (britannica.com)
  • The atomic radii of zirconium and hafnium are 1.45 and 1.44 Å, respectively, while the radii of the ions are Zr 4+ , 0.74 Å, and Hf 4+ , 0.75 Å. (britannica.com)
  • Although the chemistry of hafnium has been studied less than that of zirconium, the two are so similar that only very small quantitative differences-for example, in solubilities and volatilities of compounds-would be expected in cases that have not actually been investigated. (britannica.com)
  • Of the elements within the d-block with known electronegativities, zirconium has the fifth lowest electronegativity after hafnium , yttrium , lanthanum , and actinium . (wikipedia.org)
  • Zirconium is routinely found with a low level of hafnium since separation of the two elements is difficult. (americanelements.com)
  • Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. (usgs.gov)
  • Zirconium and hafnium are both refractory lithophile elements that have nearly identical charge, ionic radii, and ionic potentials. (usgs.gov)
  • The world's largest primary deposits of zirconium and hafnium are associated with alkaline igneous rocks, and, in one locality on the Kola Peninsula of Murmanskaya Oblast, Russia, baddeleyite is recovered as a byproduct of apatite and magnetite mining. (usgs.gov)
  • Otherwise, there are few primary igneous deposits of zirconium- and hafnium-bearing minerals with economic value at present. (usgs.gov)
  • Global consumption is expected to increase in the future, however, as demand from the ceramics, chemicals, and metals industries increases (driven by renewed growth in developing economies) and demand for zirconium and hafnium metal increases (driven by the construction and operation of new nuclear powerplants). (usgs.gov)
  • The behaviors of zirconium and hafnium in the environment are very similar to one another in that most zirconium- and hafnium-bearing minerals have limited solubility and reactivity. (usgs.gov)
  • Anthropogenic sources of zirconium, and likely hafnium, are from industrial zirconium-containing byproducts and emissions from the processing of sponge zirconium, and exposure to the general population from these sources is small. (usgs.gov)
  • Zirconium and hafnium are likely not essential to human health and generally are considered to be of low toxicity to humans. (usgs.gov)
  • Because of the low solubility of zirconium and hafnium, ecological health concerns in the aquatic environment and in soils are minimal. (usgs.gov)
  • cubic zirconia
  • This open-style, double-heart pendant necklace shows your romantic side by blending together sparkling cubic zirconia and polished sterling silver to create one very special accessory. (jcpenney.com)
  • sponge
  • The production of nuclear-grade zirconium sponge and the fabrication of zirconium-base alloys have been considered vital in some European countries, because of the need for zirconium independence for military (atomic bomb) or economic (nuclear power plant) reasons. (astm.org)
  • chemical
  • Zirconium (Zr) , chemical element , metal of Group 4 (IVb) of the periodic table , used as a structural material for nuclear reactors . (britannica.com)
  • Zirconium is a chemical element with symbol Zr and atomic number 40. (wikipedia.org)
  • American Elements produces high purity (6N 99.9999%) zirconium triselenide single crystals with low defect density via flux zone or chemical vapor transport (CVT) growth techniques. (americanelements.com)
  • To the best of our knowledge the chemical, physical, and toxicological properties of zirconium silicide have not been thoroughly investigated and reported. (espimetals.com)
  • ductile
  • Pyrolysis of zirconium(IV) iodide gas by contact of hot wire was the first industrial process for the commercial production of pure ductile metallic zirconium. (wikipedia.org)
  • Zirconium is a lustrous , greyish-white, soft, ductile , malleable metal that is solid at room temperature, though it is hard and brittle at lesser purities. (wikipedia.org)
  • metal
  • It is an orange-coloured solid that degrades in the presence of water.The compound was once prominent as an intermediate in the purification of zirconium metal. (wikipedia.org)
  • It is prepared by the direct reaction of powdered zirconium metal and iodine. (wikipedia.org)
  • Zirconium Triselenide is a layered transition metal dichalcogenide (TMDC) semiconductor that exhibits superconducting properties at low temperatures (~2K). (americanelements.com)
  • Zirconium Vanadium is one of numerous metal alloys sold by American Elements under the trade name AE Alloys™ . (americanelements.com)
  • room temperature
  • At room temperature zirconium exhibits a hexagonally close-packed crystal structure, α-Zr, which changes to β-Zr, a body-centered cubic crystal structure, at 863 °C. Zirconium exists in the β-phase until the melting point. (wikipedia.org)
  • nuclear
  • Zirconium, obscure before the late 1940s, became a significant engineering material for nuclear energy applications because it is highly transparent to neutrons . (britannica.com)
  • The most important use of zirconium is in nuclear reactors for cladding fuel rods, for alloying with uranium , and for reactor-core structures because of its unique combination of properties. (britannica.com)
  • The original paper was published by ASTM International in STP 939, Zirconium in the Nuclear Industry: Seventh International Symposium , 1987, pp. 35-46. (astm.org)
  • generally
  • Global consumption of zirconium mineral concentrates generally increased during the same time period, largely as a result of increased demand in developing economies in Asia and the Middle East. (usgs.gov)
  • corrosion
  • Zirconium has good strength at elevated temperatures, resists corrosion from the rapidly circulating coolants, does not form highly radioactive isotopes , and withstands mechanical damage from neutron bombardment. (britannica.com)
  • Zirconium is highly resistant to corrosion by alkalis, acids, salt water and other agents. (wikipedia.org)