Friday, May 3, 2013

Rare earth elements Geological distribution


Rare Earth elements are a group of 17 elements present in the periodic table (15 Lanthanoids, Scandium and Yttrium). Scandium and Yttrium are chemically similar and present in the same ores as Lanthanoids.

These are abundant in the Earth (except Promethium). Cerium is such as copper, the most spacious 25th (68 parts per million) element. These reserves are spread, rather than found in clusters and marketable varieties are called the minerals of the rare earth . Their name came into being thanks to the scarcity of these minerals. Gadolinite was the first connection in Sweden discovered by Arrhenius, a professor at the University.

In 1803, another rare earth-element Served was discovered. It was soon revealed that the substance consisted of other elements within it.

In 1839, the elements were separated from the compound and by 1842; four more elements was discovered. Now, four elements were Earth-Yttrium, Cerium, lanthanum known to exist, Erbium and Terbium Didymium,. Soon a new mineral discovered, with more elements within it.

The ingredients were found by means of x-ray diffraction. 25 rare earth elements were presumed to exist with an undiscovered chemical element present in them. Soon, the ion exchange method was developed and extraction of these metals was more efficient.

The 17 rare earth elements include:

-Scandium
-Yttrium
-Lanthanum
-Cerium
-Praseodymium
-Neodymium
-Promethium
-Samarium
-Europium
-Gadolinium
-Terbium
-Dysprosium
-Holmium
-Erbium
-Thulium
-Ytterbium
-Lutetium

They are either named after the discover scientist or the location where they are first found.

Cerium is usually found with Monazite and is found in large quantities. Yttrium is found with phosphates and is relatively rare. It is primarily found in South China. Gadolinite and Xenotime, among others, are common minerals that contain Yttrium. Major ores of Cerium include Bastnaesite (California, China) and Loparite (Russia). Deposits of earth minerals are present on the seabed also known.

Most rare earth elements were produced in India and Brazil, before deposits were found in Africa and California. China is currently the largest producer. Thanks to the increased demand for minerals and chance of reserves be exhausting, that China exports has fallen. Other countries are working to meet the needs of the population. Recycling of metals is examined as prices mount.

Extracting, metal recycling, disposal of toxic waste and the acids used in refining can be extremely dangerous and can lead to diseases such as leukemia (in Malaysia). Countries time takeoff from extraction to prevent these side effects (e.g. China). Birth defects have also occurred due to the fact that the radioactive ores can be.

China, whose rare earth industry has accelerated in recent decades, recently became a part of this industry because it is better for valuable objects in comparison with others. Thanks to domestic demand, China will slow down export to 130-140,000 tonnes instead of 129,000 tonnes in 2009 (total 132,000 used).

Rare earth metals are sold in private markets and so it is difficult to check their prices. However, people are now taking the purity of the metal that they need to give them the price.