Yttrium group 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). 

Most important mineral Yttrium has given the name to the heavy REM-group, the yttrium group. Minerals typical for this group are euxenite (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)20g and fergtisortite Y(Nb,Ta)0. Figure M18. 

Scandium is very widely but thinly distributed and its only rich mineral is the rare thortveitite, Sc2Si20v (p. 348), found in Norway, but since scandium has only small-scale commercial use, and can be obtained as a byproduct in the extraction of other materials, this is not a critical problem. Yttrium and lanthanum are invariably associated with lanthanide elements, the former (Y) with the heavier or Yttrium group lanthanides in minerals such as xenotime, M "P04 and gadolinite, M M SijOio (M = Fe, Be), and the latter (La) with the lighter or cerium group lanthanides in minerals such as monazite, M P04 and bastnaesite, M C03F. This association of similar metals is a reflection of their ionic radii. While La is similar in size to the early lanthanides which immediately follow it in the periodic table, Y , because of the steady fall in ionic radius along the lanthanide series (p. 1234), is more akin to the later lanthanides. 

Limited research studies [6] show that the minerals from the yttrium groups can be recovered using alkyl hydroxamate collectors which form complex reactions with REO. 

Figure 24.4 Generalized flowsheet for beneficiation of yttrium group of minerals using flotation.

In a number of cases, the REO from the yttrium group contains significant amounts of pyrochlore and/or tantalum columbite. Both minerals usually float with the zircon and REO minerals. 

The lanthanide contraction is probably the reason why the natural processes lead to fractionation and give rise to cerium group elements containing mainly the larger rare earth elements of lower atomic numbers, and to yttrium earth minerals containing mainly smaller rare earth elements with higher atomic numbers. Yttrium, although not a rare earth element, its atomic number 39 is low and its radius is similar to that of Ho. Thus yttrium appears with heavy rare earth elements. 

Source Monazite, bastnasite, and related fluocarbo-nate minerals as well as minerals of the yttrium group. These ores contain varying percentages of rare-earth oxides, which are often loosely called rare earths. Rare earth elements also occur as fission products of uranium and plutonium. 

In the formulae for minerals Y Is to be msli.nttooil m representing yttrium group elements, and Ce, cerium group elements. 

Fleischer M, Altschuler ZS (1986) The lanthanides and yttrium in minerals of the apatite group - an analysis of the available data. N Jahrb Mineral Monatsh 467-480 Fleischer M, Mandarine JA (1995) Glossary of Mineral Species (7th ed). Mineral Record, Tucson, Arizona. Fortsch E, Freiburg IB (1970) Untersuchungen as mineralien der pyromorphit grappe. N Jahib Mineral Abh 113 219-250... 

The most important rare earth minerals are listed in the following table where Ce and Y represent concentrations particularly of the cerium and yttrium groups, respectively ... 

Monazite, the orthophosphate of the cerium group rare earths, is, without doubt, the most important rare earth mineral. It contains cerium-group oxides (49 to 74 per cent), yttrium-group oxides (1 to 4 per cent), thoria (1 to 20 per cent), and variable quantities of silica, iron (III) oxide, alumina, etc. Typical commercial samples of... 

Mineral Formula Cerium group earths, % Yttrium group earths, % Other oxides, %... 

In 1877, Mallet discovered an yttrium niobate mineral called sipylite in Virginia (USA). Analyzing it he found that it contained niobium and cerium and yttrium group elements (Mallet 1877). In 1878, Delafontaine identified Marignac s ytterbium in this mineral too (Delafontaine 1878d). 

Bastnaesite belongs to the carbonatite group of minerals that contain REOEs. Beside the cerium group of elements, bastnaesite also contains yttrium and europium. Typically, it contains 65-75% REOE. Bastnaesite is usually found in pegmatites, carbonatite and hydrothermal ore bodies in alkaline gangue minerals. Because it is poor chemically and stable, it is not found in mineral sand deposits. 

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