Ytterbium abundance

Yttrium (j Y) is often confused with another element of the lanthanide series of rare Earths— Ytterbium ( Yb). Also confusing is the fact that the rare-earth elements terbium and erbium were found in the same minerals in the same quarry in Sweden. Yttrium ranks second in abundance of all 16 rare-earth, and Ytterbium ranks 10th. Yttrium is a dark silvery-gray hghtweight metal that, in the form of powder or shavings, will ignite spontaneously. Therefore, it is considered a moderately active rare-earth metal. 

Ytterbium is the 45th most abundant element, and it ranks 10th in abundance (2.7 ppm) among the 17 rare-earths found in the Earth s crust. 

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. 

Of the remaining elements such as holmium, erbium, thulium ytterbium and lutetium it is unfortunately true that their relatively low abundance coupled with high cost has tended to preclude their use in applications outside of the laboratory. 

Even more striking in the old tooth is the abundance of rare earths (dysprosium, holmium, erbium, thulium, ytterbium, and lutetium) and the elements tantalum, tungsten, gold, thorium, and uranium. Rare earth minerals are found in Scandinavia (in fact, many rare earth elements were discovered there), but what were they used for Did people prepare food with them Did they somehow get into the food chain ... 

Ytterbium is one of the more common lanthanoids. It is thought to have an abundance of about 2.7 to 8 parts per million in Earth s crust. That makes it somewhat more common than bromine, uranium, tin, and arsenic. Its most common ore is monazite, which is found in beach sands in Brazil, India, and Florida, among other places. Monazite typically contains about 0.03 percent ytterbium. 

The perception that lanthanide metals were rare and therefore inaccessible or expensive was a contributing factor to their long-lasting neglect and slow develo nent as useful synthetic tools, hi fact, rare earths in general are relatively plentiful in terms of their abundance in the earth s crust. Samarium and ytterbium occur in proportions nearly equal to those of boron and tin, for example. Modem separation methods have made virtually all of the lanthanides readily available in pure form at reasonable cost. 

The final isolation from the "cerite tree" occurred in 1901 when Eugene-Anatole Demargay (1852-1904) reported the separation of europium (Eu). The final isolation from the "ytterbite tree" was reported in 1907 when lutetium (Lu) was separated from the more abundant ytterbium (Yb). The element was discovered by Georges Urbain (1872-1938), at the Sorbonne, and independently... 

It would be a preferable situation if the demand for elements that are very abundant would control the REE market. Unfortunately, this is not the case. The most wanted elements at this time are neod3unium and dysprosium (Binnemans et al. 2013). Cerium, praseodymium, and the heavy REEs holmium, gadohnium, thulium, ytterbium and lutetium are produced in excess, and are stockpiled. 

Daane and Spedding 1953), but in each case, only reduction to the SmCl2 or SmF2 state was achieved. The substitution of other alkaline earth and alkali metals for calcium served to no avail. Similar results were obtained for the less abundant europium and ytterbium. 

Known rare-earth minerals were few gadolinite and ce-rite were extremely rare and the other minerals (there were about ten of them) could be likened, as regards their abundance, to museum pieces. Nevertheless, the era of new discoveries had come and the first sprouts appeared on the yttrium tree. Mosander s erbium remained controversial for a long time and only in 1878 did the Swiss scientist J. de Marignac separate a new element from erbium he named it ytterbium also after the village of Ytterby. 

The rare earth minerals are composed of scandium, yttrium, and the lanthanides. The lanthanides comprise a group of 15 elements that include lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Cerium is the most abundant element in the rare earth group at 60 ppm, followed by yttrium at 33 ppm, lanthanum at 30 ppm, and neodymium at 28 ppm. Thulium and lutetium are the least abundant at 0.5 ppm. 

Besides triplet-triplet annihilation, a further process for achieving upconversion luminescence emission under continuous wave low-energy irradiation is based oti the use of lanthanide ions, most often erbium, holmium, and thulium (III) cations. In particular, a large variety of phosphors based on an inorganic host doped by lanthanide cations have been developed. The abundance of available states in these cations opens a large variety of paths for upconversion. As an example (Scheme 7.6), upconversion nanoparticles codoped with ytterbium and erbium cations exhibit a green emission due to the transitions from Hn/2 and respectively " Sn/2 excited states to the ground state as well as a red emission from the F9/2 state [10]. 

It surprises most people to learn that several of the so-called rare earth elements are not actually that rare compared to much more familiar elements. Neodymium, praseodymium, samarium, gadolinium, dysprosium, erbium, and ytterbium are all more abundant than more familiar elements like bromine, uranium, or tin. Europium, holmium, terbium, lutetium, and thulium are more abundant than iodine, silver, or mercury. Yet few people have even heard of most of the rare earths. The reason is that rare earths tend not to concentrate in large ore deposits in the way that better known metals do. Historically there have been fewer profits to be made from mining rare earth elements, and there have been fewer applications developed for them in industry. 

Three lanthanides (samarium, europium and ytterbium) have divalent states that are capable of being exploited, but only Eu " has any appreciable stability in aqueous solutions. Furthermore, due to the relatively low abundance of all three, it is not expedient to utilize the properties of the divalent state until a moderate degree of enrichment has been achieved by other means. Then Eu(III) is easily reduced to Eu(II) by zinc, and europium(II) sulfate can be recovered as a precipitate isomorphous with BaS04, McCoy (1935). 

---