Minerals zircon

Zirconium is found in at least 37 different mineral forms (6) but the predorninant commercial source is the mineral zircon, zirconium orthosiUcate. Other current mineral sources are baddeleyite and eudialyte [12173-26-1]. 

Ion bomliardment Heaw -mineral concentrate Conductor minerals (ilmenite, riitilej from non-condiictor minerals (zircon, monazite, ahiminiim. silicates, (piartz and others j Roll 120 -1.0 + 0.04 2.5 3-6... 

In the drying of compound intermediates of refractory and reactive metals, particular attention is given to the environment and to the materials so that the compound does not pick up impurities during the process. A good example is the drying of zirconium hydroxide. After the solvent extraction separation from hafnium, which co-occurs with zirconium in the mineral zircon, the zirconium values are precipitated as zirconium hydroxide. The hydroxide is dried first at 250 °C for 12 h in air in stainless steel trays and then at 850 °C on the silicon carbide hearth of a muffle furnace. 

There are many advantages of using metal chlorides as interprocess intermediates. One of the most important advantages is that the metal chlorides could be readily purified. In other words, co-occurring metals could be more readily separated from one another as chlorides. This is particularly important when the co-occurring metals have very different technological properties and the presence of one in another in the final product is detrimental to the intended commercial application. A famous example of such co-occurrence is that of zirconium and hafnium in the mineral zircon. Not more than 100 ppm hafnium should be present in the zirconium intended for use in the nuclear reactor core. The hafnium content of zircon is about 2.5%. 

Uraninite is associated with the following minerals zircon, monazite, carbonaceous material (thucolite ), mica, feldspar, and with rare-earth-bearing minerals. It occurs in small distinct crystals or may be massive. Some grains are discoloured, especially in the centre, metamict, and fractured. 

German chemist Martin Heinrich Klaproth Durable metal highly resistant to heat its mineral zircon, a compound of zirconium silicate, is a semiprecious gem often substituted for diamonds. 

Hafnium is obtained commercially from mineral zircon, which is zirconium orthosilicate [14940-68-2]. Zircon usually contains hafnium oxide, Hf02, in an amount that ranges between 1 to 2%. Zircon sand is separated from heavy... 

Zirconium silicate occurs in nature as mineral zircon. Ore is mined from natural deposits and concentrated by various techniques (See Zirconium, Recovery). It is separated from sand by electrostatic and electromagnetic methods. 

Under Reflected Light. Radioactive minerals (zircon, uraninite, coffinite) enclosed in organic material are surrounded by a clear halo of more than 20 microns width (Figure 1). This halo corresponds to a zone of increased anisotropy, reflectivity, and hardness as first observed by Stach (24). 

The simplest silicates, the orthosilicates, are built from Si044 ions. They are not very common but include the mineral zircon, ZrSi04, which is used as a substitute for diamond in costume jewelry. The pyroxenes... 

The mineral zircon (ZrSi04) is a relatively inexpensive gemstone. 

Heavy minerals and accessory minerals Zircon, rutile, tourmaline, orthoclase, biotite — Chlorides, sulfates, nitrates —... 

Another example is found in the analysis of the mineral zircon. We had previously published [4] a spectrum of a positive ion laser desorption spectrum of a sample of the mineral zircon (zirconium silicate) showing uranium as 238U+, present in the sample at a level of approximately 15 parts-per-million [41]. The spectrum, which showed mixed zirconium oxides and hydroxides as the most intense peaks in the spectrum, was taken with a four second delay between the laser pulse and ion detection, in order to allow neutrals to be pumped out of the cell. These conditions had been found adequate for analysis of organic compounds. However, it was found that the reactivity of zirconium was such that the mixed oxides and hydroxides were produced as ion-molecule reaction products during the long trap period. 

Hafnium was discovered in 1923 by Danish chemist Dirk Coster working together with Hungarian physicist Gyorgy K. Hevesy. The electronic structure of hafnium had been predicted by Niels Bohr, and Coster and Hevesy found evidence of a substance whose pattern matched what had been predicted. The element predicted by Bohr was finally identified as being part of the mineral zircon by means of x-ray spectroscopy analysis. Due to its discovery in Copenhagen (whose ancient Latin name was Hafnia), the element was named hafnium. 

Cubic stabilized zirconia (CSZ) Pure zirconia (Zr02) is either chemically extracted and purified from the mineral zircon (ZrSi04) or purified from baddeleyite. It occurs as three crystalline polymorphs with monoclinic, tetragonal and cubic structures. The monoclinic form is stable up to 1170°C... 

Nesosilicates are the simplest silicates. They contain isolated or independent Si04 tetrahedra. This group has also been called the orthosilicates. A secondary classification, the nesosubsilicates has been designated by Strunz (1957), who was the originator of the silicate classification. This subclass included species having a second anion or anionic radical. The nesosilicates include the gem minerals zircon, topaz, and the garnet and olivine groups. 

Zirconium occurs in nature principally as the mineral zircon, ZrSi04. Zircon crystals are found in a variety of colors—white, blue, green, and red—and because of its beauty and hardness (7.5) the mineral is used as a semi-precious stone. The principal oxidation state of zirconium is 4-4 the states - -2 and - -3 are repre> sented by only a few compounds. 

The mineral zircon (ZrSi04) occurs in nature as component of acidic igneous rocks. Their weathering yields sediments containing small crystals (sand) of zircon and further heavy minerals. These deposits are resources for industrial production. 

There are a number of ways of obtaining U-Pb ages on zircons, but in the last two decades the use of the ion microprobe has become the method of choice. Zircon (zirconium silicate, ZrSi04) is a common mineral in granitic rocks, often abundant as a detrital mineral in clastic sediments and a rare accessory mineral in mafic rocks and some metamorphic rocks. The frequent occurrence of the mineral zircon, and its resilience to later thermal events that would reset other isotopic systems are the reasons for its frequent use in studies of the early Earth. 

Zr zirconium, 40, 1789 from the mineral zircon, in which it is found. 

Coarse-grained sedimentary rocks typically have REE patterns essentially parallel to those of shales, but with lower total abundances than shales, due mainly to the diluting effect of quartz. The overall shape of the patterns (Eu/Eu, La/Yb) is generally similar for sandstones and shales. The REE abundances in quartz-rich sedimentary rocks are typically very low. The potential of heavy minerals to distort REE patterns in sedimentary rocks is well recognized. However, these minerals are only rarely concentrated in amounts sufficient to cause perceptible effects on the REE patterns. Thus the resistant mineral zircon, typically enriched in heavy REE, affects the bulkrockpatterns only when zircon constitutes more than about 0.06% (or Zr abundances exceed about 300 ppm), since every 100 ppm of Zr as zircon adds only about 0.25 times the chondritic levels of Yb (typical shale patterns are about 10-15 times chondritic levels for that element). 

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