Extraction chromatographic separations of tantalum and tungsten from hafnium and complex matrix constituents.

See more Hafnium products. Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electron configuration is [Xe] 4f¹⁴ 5d² 6s². The hafnium atom has a radius of 159 pm and a Van der Waals radius of 212 pm. Hafnium was predicted by Dmitri Mendeleev in 1869 but it was not until 1922 that it was first isolated Dirk Coster and George de Hevesy. In its elemental form, hafnium has a lustrous silvery-gray appearance. Hafnium does not exist as a free element in nature. It is found in zirconium compounds such as zircon. Hafnium is often a component of superalloys and circuits used in semiconductor device fabrication. Its name is derived from the Latin word Hafnia, meaning Copenhagen, where it was discovered.

See more Tantalum products. Tantalum (atomic symbol: Ta, atomic number: 73) is a Block D, Group 5, Period 6 element with an atomic weight of 180.94788. The number of electrons in each of tantalum's shells is [2, 8, 18, 32, 11, 2] and its electron configuration is [Xe] 4f¹⁴ 5d³ 6s². The tantalum atom has a radius of 146 pm and a Van der Waals radius of 217 pm. Tantalum was first discovered by Anders G. Ekeberg in 1802 in Uppsala, Sweden however, it was not until 1844 when Heinrich Rose first recognized it as a distinct element. In its elemental form, tantalum has a grayish blue appearance. Tantalum is found in the minerals tantalite, microlite, wodginite, euxenite, and polycrase. Due to the close relation of tantalum to niobium in the periodic table, Tantalum's name originates from the Greek word Tantalos meaning Father of Niobe in Greek mythology.

See more Tungsten products. Tungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f¹⁴ 5d⁴ 6s². The tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance. Tungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO₄) and wolframite [(Fe,Mn)WO₄]. In reference to its density, Tungsten gets its name from the Swedish words tung and sten, meaning heavy stone.