Ytterbium REE Collection rare earth metals elements

Ytterbium

It is the ultimate pairing of yttrium and erbium. A portmanteau of the two elements, the discoverer linguistically forged ytterbium, alluding to its characteristic properties between those of yttrium and erbium. The new middle “earth” was to wield unimaginable powers. With six paired electrons its properties impart high-energy to lasers, penetrate thick steel to test quality, destroy cancer cells with gamma rays, strengthen turbine blades, and inscribe indentifying marks, codes, and symbols.

Applications

  • Pulsed green ytterbium fiber lasers are used in ablation, micromachining, texturing and marking vehicle part identification numbers, medical products, and implants.
  • Ytterbium lasers are used to drill into diamonds to remove imperfections.
  • Heat-treatment with ytterbium lasers is used to surface-harden turbine blades, threads on industrial tools, and piston rings.
  • Implanted radioactive ytterbium-169 is used to fight cancerous cells.

Interesting Facts

  • Ytterbium is the only element named by combing the names of two other elements, yttrium and erbium.
  • An ytterbium clock based on optical frequencies can keep time to within 1 second in about 100 million years, a precision comparable to the NIST-F1 cesium fountain clock, the civilian time standard in the United States.
  • Ytterbium metal is used in stress gauges to monitor ground deformations from earthquakes.

Discovery

Swiss chemist Jean-Charles Galissard Marignac discovered ytterbium in 1878 from an impure erbia (de Marignac, 1878). He continued to analyze the erbium faction to obtain a new “earth” whose oxide and salts were different from those of erbium. Differing from erbium in both chemical and spectral characteristics, the ytterbium oxide was a white substance that did not absorb light, while the erbium oxide was rose-colored and had discernible spectral absorption lines (Weeks and Leicester, 1968, p. 680). With limited material to continue his analysis, Marignac abandoned further study of the ytterbium and requested others to carry on the research. Starting with larger quantities of mineral concentrates, Swedish chemist Lars Fredrick Nilson, who would subsequently discover scandium, confirmed the findings by using the same methodology using thirteen series of decompositions, heating to solidification the nitrates, and precipitation of the insoluble nitrates with oxalic acid. This was followed by an additional eight steps of purification of the solutions from which the insoluble nitrates had been precipitated. By heating the nitrate in the decomposition steps just to the point where the molten nitrate was barely viscous, the erbium impurities were removed and the molecular weights of ytterbium were verified along with the lack of spectral absorption bands (Nilson, 1879). In the same year, Marignac’s ytterbium was also identified by Delafontaine in an yttrium-niobate mineral named “sipylite,” now called fergusonite-(Y), which was discovered two years earlier in Virginia, USA, by John William Mallet. Marignac named the new element “ytterbium” because its properties were between those of yttrium and erbium. Yttrium and erbium were both named for the small village and mine location in Sweden where the original rare-earth yttrium-bearing mineral was discovered, Ytterby.

Definition

Ytterbium is a bright silvery metal that is relatively stable in air and reacts slowly in water. The metal is soft, quite ductile, and malleable. It is a mixture of seven stable isotopes. At ambient temperatures it has a face-centered cubic structure, a density of 6.965 gm/cm3, a melting point of 819 °C, and a boiling point of 1196 °C. Above 798 °C to its melting point, ytterbium’s structure transforms to body-centered cubic with a density of 6.54. Ytterbium oxide, or ytterbia, occurs as a sesquioxide with the formula Yb2O3. The oxide is a white powder with a specific gravity of 9.17 gm/cm3, a melting point of 2355 °C, a boiling point of 4070 °C, and a formula weight of 394.08.

Preparation of Metal

Ytterbium metal is typically prepared by metallothermic reduction of the oxide, since it will not reduce from the trihalide because of its high vapor pressure. This is similar to the procedure for Sm, Eu, and Tm. The oxide is is heated in air to 625 °C for 15 hours to drive off absorbed moisture, carbon dioxide, and other compounds. Ytterbium oxide is reduced with lanthanum metal turnings (15% in excess of theoretical amount) by volatilization within a tantalum crucible with an attached tantalum condenser. The reactants are heated in a vacuum reduction furnace by slowing raising the temperature to 1400 °C and held at temperature for several hours (Beaudry and Gschneidner, Jr., 1978). Ytterbium metal is formed starting at 625 °C when the oxide preferentially separates from the ytterbium oxide and combines with the lanthanum metal forming lanthanum oxide and forms a sublimated ytterbium metal within the tantalum condenser.

Source

Large resources of ytterbium are in xenotime, synchisite-(Y), eudialyte-(Y), and ion adsorption ores. They are available worldwide in ancient and recent placer deposits, igneous alkalic deposits, uranium ores, and weathered clay deposits (ion-adsorption ore). It occurs in the Earth’s crust at an average concentration of 3 parts per million. Additional large subeconomic resources of yttrium occur in apatite-magnetite-bearing rocks, deposits of niobium-tantalum minerals, non-placer monazite-bearing deposits, and sedimentary phosphate deposits. Additional resources in Canada are contained in fergusonite and xenotime at Nechalacho (Thor Lake), Northwest Territories; and eudialyte-(Y), mosandrite, and britholite at Kipawa, Quebec. It occurs in various minerals in differing concentrations and occurs in a wide variety of geologic environments, including alkaline granites and intrusives, hydrothermal deposits, laterites, placers, and vein-type deposits (Hedrick, 2010).

Mining

Ytterbium is mined from a variety of ore minerals and deposits using various methods. Xenotime, with Yb2O3 contents of 6.0% to 6.77% of the total REO content, is recovered from heavy-mineral sands (specific gravity >2.9) deposits in various parts of the world as a byproduct of mining zircon and titanium-minerals or tin minerals. Heavy mineral sands are recovered by surface placer methods from unconsolidated sands. Many of these deposits are mined using floating dredges which separate the heavy-mineral sands from the lighter weight fraction with an on-board wet mill through a series of wet-gravity equipment that includes screens, hydrocyclones, spirals, and cone concentrators. Consolidated or partially consolidated sand deposits that are too difficult to mine by dredging are mined by dry methods. Ore is stripped by typical earth-moving equipment with bulldozers, scrapers, and loaders or by water jet methods. Ore recovered by these methods is crushed and screened and then processed by the wet mill described above. Wet mill heavy-mineral concentrate is sent to a dry mill for processing to separate the individual heavy-minerals using a combination of scrubbing, drying, screening, electrostatic, electromagnetic, magnetic, and gravity processes (Hedrick, 1991). Vein monazite has been mined by hard-rock methods in South Africa and the United States, and as a byproduct of tungsten mining in China (Hedrick, 2010). In Russia, loparite is mined by underground methods using room and pillar methods. Ore is drilled and blasted and hauled to the mill. At the mill the blasted ore is crushed, screened, and processed by flotation to produce a loparite concentrate with a 0.2% Yb2O3 REO grade. The Monazite-(Nd) at Lemhi Pass, Idaho-Montana, USA, has an Yb2O3 grade of 0.21%, similar to Russian loparite. In Kyrgyzstan, synchysite-(Y) concentrate with a Yb2O3 content of 1.2% to 3.3% of the REO content was mined by hard-rock methods from the open-pit Kutessai-II deposit near Aktyuz (Hedrick, Sinha, and Kosynkin, 1997). Argillaceous marine sediments enriched in fossil fish remains at the Melovie deposit in Kazakhstan were previously recovered for their uranium and rare-earth content, including ytterbium. The main source of the world’s ytterbium is the ion-adsorption lateritic clays with Yb2O3 contents of 0.3% to 0.6% in the Xunwu ore and 2.5% to 3.5% in the Longnan ore’s REO grade. These ores are mined in the southern provinces of China, primarily Fujian, Guangdong, and Jiangxi, with a lesser number of deposits in Guangxi and Hunan. These deposits are mined by leaching methods (Hedrick, 2010).

Selected ytterbium-bearing minerals

Xenotime Y(PO4)
Gadolinite-(Y) Y2Fe2+Be2(Si2O10)
Synchysite-(Y) Ca(Y,Ce)(CO3)2F
Eudialyte-(Y) Na4(Ca,Ce)2(Fe2+,Mn,Y)ZrSi8O22(OH,Cl)2
Loparite-(Ce) (Ce,Na,Ca,Sr,Th)(Ti,Nb,Ta,Fe+3)O3
Monazite-(Nd) (Nd,Ce,La,Th)(PO4)
Mosandrite Na2Ca4(REE)(Si2O7)2OF3
Britholite-(Y) Ca2(Y,Ca)3(SiO4,PO4)3(OH,F)
Monazite (Ce,La,Nd,Th)(PO4)
Ion adsorption lateritic clays Y-enriched lateritic clays

References

Beaudry and Bernard J. and Karl A. Gschneidner, Jr., 1978, Preparation and Basic Properties of the Rare Earth Metals: chapter 2 in Handbook of the Physics and Chemistry of Rare Earths-Volume 1:Metals, (Gschneidner, Jr. and Eyring, editors), North-Holland, New York, p. 173-232.

Gschneidner, Karl A. Jr., 2011, The Rare Earth Crisis—The Supply/Demand Situation for 2010-2015: article in Material Matters, Aldrich Chemical Co., Milwaukee, Wisconsin, v. 6, no. 2, p. 34-35.

Hedrick, James B., 2010, Rare earths: chapter in Mineral commodity summaries 2010, U.S. Geological Survey, p. 128-129.

Hedrick, James B., 1990, Rare earths—The lanthanides, yttrium, and scandium: chapter in Minerals Yearbook 1990, U.S. Geological Survey, v. 1, p. 903-922.

Hedrick, James B., 1991, Rare earths—The lanthanides, yttrium, and scandium: chapter in Minerals Yearbook 1991, U.S. Geological Survey, v. 1, p. 1211-1237.

Hedrick, James B., 2010, Yttrium: chapter in Mineral commodity summaries 2010, U.S. Geological Survey, p. 182-183.

Hedrick, James B., Shyama P. Sinha, and Valery D. Kosynkin, 1997, Loparite—a rare-earth ore (Ce,Na,Sr,Ca)(Ti,Nb,Ta,Fe+3)O3: Journal of Alloys and Compounds, v. 250, p. 467-470.

de Marignac, Jean-Charles Galissard, 1878, Sur l’ytterbine, terre nouvelle, contenu dans la gadoinite [On ytterbium oxide, a new earth, contained in gadolinite]: Comptes Rendus, v. 87, p. 578.

Nilson, Lars Fredrick, 1879, About yttterbine, the new earth of Marignac: Comptes Rendus, v. 88, p. 642-647.

Weeks, Mary E., and Henry M. Leicester, 1968, Discovery of the Elements (7th ed.): Easton, Pennsylvania, Journal of Chemical Education, 896 p.

Electrons per shell:
2, 8, 18, 32, 8, 2
Atomic number,
Protons, Electrons:
70
Number of Neutrons:
103
Atomic Mass:
173.04 amu
Melting Point:
819.0 °C
Boiling Point:
1196.0 °C
Density @ 293 K:
6.965 g/cm3
Crystal structure:
cubic
Color:
silvery