Minerals euxenite

The element was discovered by Nilson in 1878 in the minerals euxenite and gadolinite, which had not yet been found anywhere except in Scandinavia. By processing 10 kg of euxenite and other residues of rare-earth minerals, Nilson was able to prepare about 2g of highly pure scandium oxide. Later scientists pointed out that Nilson s scandium was idenhcal with Mendeleev s ekaboron. 

In addition to meeting the foregoing requirements, a good internal standard will be easy to add uniformly and precisely, and (preferably) no appreciable amount of the element St (free or combined) will be present in the sample before the addition. Cope29 provides an excellent illustration of these points. He found that yttrium nitrate dissolved in ethyl alcohol could be added to a powdered uranium mineral in a mortar, whereupon grinding immediately to dryness dispersed the internal standard (yttrium) so uniformly that uranium could be satisfactorily determined in certain minerals. But the mineral euxenite is an exception, for it contains both yttrium and uranium, and this complicates the uranium determination with yttrium as internal standard. 

Ytterbium occurs in minerals euxenite, a complex titanium niobotantalate gadolinite, a rare earth iron beryUium sdicate monazite, a thorium-rare earth phosphate and xenotime, also a rare earth-thorium phosphate. Abundance of ytterbium in the earth s crust is estimated to be 3.2 mg/kg. 

The discovery of Sc occurred separately from the above work. In 1840, C. J. A. Scheerer reported a new mineral euxenite which had been found near Jolster in Norway. An approximate analysis was made and many elements were detected including lanthanoids. Lars Fredrik Nilson in 1879 reported the isolation of2g of SC2O3 if om working up 10 kg of euxenite plus someresidues from several other minerals. 

The specimen Scheerer analyzed was given to him by Professor B. M. Keilhau (51). Using a very small sample, Scheerer made an appioximate quantitative analysis, from which he reported the presence of tantalic and titanic acids, yttria, uranous, cerous, and lanthanum oxides, lime, magnesia, and water. He named the mineral euxenite because of... 

He returned to Upsala, passed his examinations successfully, and was placed m charge of the laboratory. Here, among Berzelius balances, blowpipes, and preparations, he became a true disciple of that great master. After completing some researches on the compounds of selenium, Nilson and Pettersson began to study the mineral euxenite, hoping to measure the chemical and physical constants of the rare earth elements... 

Chemical analysis was a hard job. It took time, certain operations had to be carried out hundreds of times, and, said Cleve, it wasn t until after many years of work I [...] finally succeeded to isolate the real erbium earth The otherwise unknown chemist J. A. Alen from Uppsala University remembered that after 2V, year the salt was still completely intact. Nilson started with 10 kilos of the rare mineral euxenite, in order to produce 20 grams of ytterbium, and he needed 68 decomposing series, which was trying and time-consuming. ... 

Ytterby, a village in Sweden) Discovered by Mosander in 1843. Terbium is a member of the lanthanide or "rare earth" group of elements. It is found in cerite, gadolinite, and other minerals along with other rare earths. It is recovered commercially from monazite in which it is present to the extent of 0.03%, from xenotime, and from euxenite, a complex oxide containing 1% or more of terbia. 

Euxenite is a titanotantalum/niobium-containing mineral and has a complex formula (Table 24.1) with variable chemical composition. It is usually found in sand deposits together with monazite, xenotime, zircon, beryl, columbite and other minerals. 

This hydroxamate is selective towards calcite, fluorite and sericite. The yttrium group minerals that contain zircon also have highly complex mineral compositions. These ores contain fergusonite, euxenite and priorit besides other minerals that contain REO. Such deposits are found in Northern Canada (Thor Lake). 

Tantalum is the 51st most abundant element found on Earth. Although it is found in a free state, it is usually mixed with other minerals and is obtained by heating tantalum potassium fluoride or by the electrolysis of melted salts of tantalum. Tantalum is mainly obtained from the following ores and minerals columbite [(Fe, Mn, Mg)(Nb, Taj O ] tantalite [(Fe, Mn)(Ta, Nb)jOJ and euxenite [(Y, Ca, Er, La, Ce, U, Th)(Nb, Ta, Tij OJ. Tantalums ores are mined in South America, Thailand, Malaysia, Africa, Spain, and Canada. The United States has a few small native deposits but imports most of the tantalum it uses. 

Of all the 17 rare-earths in the lanthanide series, terbium is number 14 in abundance. Terbium can be separated from the minerals xenotime (YPO ) and euxenite, a mixmre of the following (Y, Ca, Er, La, Ce, Y, Th)(Nb, Ta, Ti O ). It is obtained in commercial amount from monazite sand by the ion-exchange process. Monazite may contain as much as 50% rare-earth elements, and about 0.03% of this is terbium. 

Minerals such as euxenite, fergusonite, samarskite, polycrase and loparite are highly refractory and complex in nature. These minerals may be opened up by treatment with hydrofluoric acid. While metals such as niobium, tantalum and titanium form soluble fluorides, rare earth elements form an insoluble residue of their fluorides. Such insoluble fluorides are filtered out of solution and digested with hot concentrated sulfuric acid. The rare earth sulfates formed are dissolved in cold water and thus separated from the insoluble mineral impurities. Rare earth elements in the aqueous solution are then separated by displacement ion exchange techniques outlined above. 

Holium occurs in rare-earth minerals, such as monazite, gadolinite, xeno-time, euxenite, fergusonite, and bastnasite. Its concentration in monazite is about 0.05%. Its abundance in the earth s crust is 1.3mg/kg. 

Scadium occurs in nature, very widely dispersed in low concentrations. It is found in most soils and numerous minerals in very minute quantities. The principal minerals are wolframite, euxenite, wiikite, bazzite, cassiterite, gadolinite, and throtveitite. Its abundance in the earth s crust is estimated to be 22 mg/kg. The element also has been detected in the sun and other stars. 

Terbium occurs in nature associated with other rare earths. It is found in minerals xenotime, a rare earth phosphate consisting of 1% terbia and in euxenite, a complex oxide containing about 1.3% terbia. It also is found in cerite, monazite, and gadolinite. Also, the element has been detected in stellar matter. Abundance of terbium in the earth s crust is estimated to be 1.2 mg/kg. 

Terbium is recovered from the minerals, monazite, xenotime, and euxenite. The recovery processes are quite similar to those of other lanthanide elements (See individual lanthanide elements). The metal is separated from other rare... 

Thulium was discovered in 1879 by Cleve and named after Thule, the earliest name for Scandinavia. Its oxide thulia was isolated by James in 1911. Thulium is one of the least abundant lanthanide elements and is found in very small amounts with other rare earths. It occurs in the yttrium-rich minerals xenotime, euxenite, samarskite, gadolinite, loparite, fergusonite, and yttroparisite. Also, it occurs in trace quantities in minerals monazite and... 

Euxenite (Loranskite). (Y, Ca, Ce, U, Th)-(Nb, Ta, Ti)20. A rare-earth mineral, occurring in Norway, Madagascar, Canada Pennsylvania. It is brownish-black, brilliant to vitreous sp gr 5.0—5.9 and hardness 5— 6. Used as a source of uranium, niobium and tantalum... 

Residues from uranium mining operations in Canada have been a major source of yttrium. Xenotime (YP04) found in Malaysia is another source, as well as the ion-adsorption clay minerals in China, Some apahte deposits are unusually rich in yttrium and it also is found in gadolimte, euxenite, and samarskite. 

Of these, bastnasite is the only mineral worked primarily for rare earths and both monazite and xenotime are mostly by-products of mining ilmenite, rutile, cassiterite, zircon or gold. Apatite and some multi oxide minerals like pyrochlore, euxenite, brannerite and loparite (a niobium titanate) are also commercial sources of rare earths, but production of RE from these is limited. 

Erbium ranks about number 42 in abundance in Earth s crust. It is more common than bromine, uranium, tin, silver, and mercury. It occurs in many different rare earth minerals, naturally occurring lanthanoid mixtures. Some common sources of erbium are xenotime, fergusonite, gado-linite, and euxenite. 

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