Xenotime

Formula: YPO4Mohs scale hardness: 4.5

Specific gravity: 4.4–5.1 g/cm3

Rare earth elements: Y, Tm, Dy, Er, Eu, Lu, Tb, Gd, Sc

Rare earth content, %: Y2O3 52–61,4

Other constituents, %: ThO2, UO2 upto 5; ZrO2 3; SnO2, SiO2 9; (U3O8 3)

Mineralklasse: Phosphate

thorium and uranium

Xenotime is a rare earth phosphate mineral, the major component of which is yttrium orthophosphate.

Lithiophyllite, monazite and purpurite are sometimes grouped with xenotime in the informal "anhydrous phosphates" group.

Occurring as a minor accessory mineral, xenotime is found in pegmatites and other igneous rocks, as well as gneisses rich in mica and quartz. Associated minerals include biotite and other micas, chlorite group minerals, quartz, zircon, certain feldspars, analcime, anatase, brookite, rutile, siderite and apatite.

Xenotime is used chiefly as a source of yttrium and heavy lanthanide metals (dysprosium, ytterbium, erbium and gadolinium).

California, Colorado, Georgia, North Carolina and New Hampshire (United States), Norway, Brazil, Madagascar, Afghanistan, Pakistan, Japan. Malaysian.

The highly valuable HREE are currently largely sourced either from xenotime or from ion adsorption clays with the largest deposits and operations located in China, e.g. in the Guangdong, Hunan, Jiangsu and Jiangxi provinces.

Processing of these clays is a fairly simple, low cost operation involving typically ion exchange by washing with (NH4)2SO4, removal of U and Th from the pregnant solution, precipitation of RE carbonates, filtering and calcination to obtain a mixed REO concentrate which can the further be separated and purified into individual REO. Recovery of REE in these operations typically exceeds 90%.

References

  1. https://en.wikipedia.org

  2. http://www.anzaplan.com/strategic-minerals-metals/rare-earth-minerals/rare-earth-minerals-processing/

  3. https://books.google.cl/books?id=jPskAQAAIAAJ&pg=RA4-PA13&lpg=RA4-PA13&dq=Green+Cove+Springs+Mine+monazite&source=bl&ots=8xH_PV9MoG&sig=MkXPfqzQ6OM4zmU2OWc-eHL2-GQ&hl=ru&sa=X&ved=0ahUKEwj6-bG1mfbMAhUDE5AKHYGfCWsQ6AEIKDAD#v=onepage&q&f=false

  4. http://www.xumuk.ru/encyklopedia/2/3854.html